Convert watch page to flask framework

48 files changed, 22252 insertions, 0 deletions

diff --git a/python/werkzeug/__init__.py b/python/werkzeug/__init__.py
new file mode 100644
index 0000000..e460e75
--- /dev/null
+++ b/python/werkzeug/__init__.py
@@ -0,0 +1,233 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug
+    ~~~~~~~~
+
+    Werkzeug is the Swiss Army knife of Python web development.
+
+    It provides useful classes and functions for any WSGI application to make
+    the life of a python web developer much easier.  All of the provided
+    classes are independent from each other so you can mix it with any other
+    library.
+
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import sys
+from types import ModuleType
+
+__version__ = "0.15.4"
+
+# This import magic raises concerns quite often which is why the implementation
+# and motivation is explained here in detail now.
+#
+# The majority of the functions and classes provided by Werkzeug work on the
+# HTTP and WSGI layer.  There is no useful grouping for those which is why
+# they are all importable from "werkzeug" instead of the modules where they are
+# implemented.  The downside of that is, that now everything would be loaded at
+# once, even if unused.
+#
+# The implementation of a lazy-loading module in this file replaces the
+# werkzeug package when imported from within.  Attribute access to the werkzeug
+# module will then lazily import from the modules that implement the objects.
+
+# import mapping to objects in other modules
+all_by_module = {
+    "werkzeug.debug": ["DebuggedApplication"],
+    "werkzeug.local": [
+        "Local",
+        "LocalManager",
+        "LocalProxy",
+        "LocalStack",
+        "release_local",
+    ],
+    "werkzeug.serving": ["run_simple"],
+    "werkzeug.test": ["Client", "EnvironBuilder", "create_environ", "run_wsgi_app"],
+    "werkzeug.testapp": ["test_app"],
+    "werkzeug.exceptions": ["abort", "Aborter"],
+    "werkzeug.urls": [
+        "url_decode",
+        "url_encode",
+        "url_quote",
+        "url_quote_plus",
+        "url_unquote",
+        "url_unquote_plus",
+        "url_fix",
+        "Href",
+        "iri_to_uri",
+        "uri_to_iri",
+    ],
+    "werkzeug.formparser": ["parse_form_data"],
+    "werkzeug.utils": [
+        "escape",
+        "environ_property",
+        "append_slash_redirect",
+        "redirect",
+        "cached_property",
+        "import_string",
+        "dump_cookie",
+        "parse_cookie",
+        "unescape",
+        "format_string",
+        "find_modules",
+        "header_property",
+        "html",
+        "xhtml",
+        "HTMLBuilder",
+        "validate_arguments",
+        "ArgumentValidationError",
+        "bind_arguments",
+        "secure_filename",
+    ],
+    "werkzeug.wsgi": [
+        "get_current_url",
+        "get_host",
+        "pop_path_info",
+        "peek_path_info",
+        "ClosingIterator",
+        "FileWrapper",
+        "make_line_iter",
+        "LimitedStream",
+        "responder",
+        "wrap_file",
+        "extract_path_info",
+    ],
+    "werkzeug.datastructures": [
+        "MultiDict",
+        "CombinedMultiDict",
+        "Headers",
+        "EnvironHeaders",
+        "ImmutableList",
+        "ImmutableDict",
+        "ImmutableMultiDict",
+        "TypeConversionDict",
+        "ImmutableTypeConversionDict",
+        "Accept",
+        "MIMEAccept",
+        "CharsetAccept",
+        "LanguageAccept",
+        "RequestCacheControl",
+        "ResponseCacheControl",
+        "ETags",
+        "HeaderSet",
+        "WWWAuthenticate",
+        "Authorization",
+        "FileMultiDict",
+        "CallbackDict",
+        "FileStorage",
+        "OrderedMultiDict",
+        "ImmutableOrderedMultiDict",
+    ],
+    "werkzeug.useragents": ["UserAgent"],
+    "werkzeug.http": [
+        "parse_etags",
+        "parse_date",
+        "http_date",
+        "cookie_date",
+        "parse_cache_control_header",
+        "is_resource_modified",
+        "parse_accept_header",
+        "parse_set_header",
+        "quote_etag",
+        "unquote_etag",
+        "generate_etag",
+        "dump_header",
+        "parse_list_header",
+        "parse_dict_header",
+        "parse_authorization_header",
+        "parse_www_authenticate_header",
+        "remove_entity_headers",
+        "is_entity_header",
+        "remove_hop_by_hop_headers",
+        "parse_options_header",
+        "dump_options_header",
+        "is_hop_by_hop_header",
+        "unquote_header_value",
+        "quote_header_value",
+        "HTTP_STATUS_CODES",
+    ],
+    "werkzeug.wrappers": [
+        "BaseResponse",
+        "BaseRequest",
+        "Request",
+        "Response",
+        "AcceptMixin",
+        "ETagRequestMixin",
+        "ETagResponseMixin",
+        "ResponseStreamMixin",
+        "CommonResponseDescriptorsMixin",
+        "UserAgentMixin",
+        "AuthorizationMixin",
+        "WWWAuthenticateMixin",
+        "CommonRequestDescriptorsMixin",
+    ],
+    "werkzeug.middleware.dispatcher": ["DispatcherMiddleware"],
+    "werkzeug.middleware.shared_data": ["SharedDataMiddleware"],
+    "werkzeug.security": ["generate_password_hash", "check_password_hash"],
+    # the undocumented easteregg ;-)
+    "werkzeug._internal": ["_easteregg"],
+}
+
+# modules that should be imported when accessed as attributes of werkzeug
+attribute_modules = frozenset(["exceptions", "routing"])
+
+object_origins = {}
+for module, items in all_by_module.items():
+    for item in items:
+        object_origins[item] = module
+
+
+class module(ModuleType):
+    """Automatically import objects from the modules."""
+
+    def __getattr__(self, name):
+        if name in object_origins:
+            module = __import__(object_origins[name], None, None, [name])
+            for extra_name in all_by_module[module.__name__]:
+                setattr(self, extra_name, getattr(module, extra_name))
+            return getattr(module, name)
+        elif name in attribute_modules:
+            __import__("werkzeug." + name)
+        return ModuleType.__getattribute__(self, name)
+
+    def __dir__(self):
+        """Just show what we want to show."""
+        result = list(new_module.__all__)
+        result.extend(
+            (
+                "__file__",
+                "__doc__",
+                "__all__",
+                "__docformat__",
+                "__name__",
+                "__path__",
+                "__package__",
+                "__version__",
+            )
+        )
+        return result
+
+
+# keep a reference to this module so that it's not garbage collected
+old_module = sys.modules["werkzeug"]
+
+
+# setup the new module and patch it into the dict of loaded modules
+new_module = sys.modules["werkzeug"] = module("werkzeug")
+new_module.__dict__.update(
+    {
+        "__file__": __file__,
+        "__package__": "werkzeug",
+        "__path__": __path__,
+        "__doc__": __doc__,
+        "__version__": __version__,
+        "__all__": tuple(object_origins) + tuple(attribute_modules),
+        "__docformat__": "restructuredtext en",
+    }
+)
+
+
+# Due to bootstrapping issues we need to import exceptions here.
+# Don't ask :-(
+__import__("werkzeug.exceptions")
diff --git a/python/werkzeug/_compat.py b/python/werkzeug/_compat.py
new file mode 100644
index 0000000..1097983
--- /dev/null
+++ b/python/werkzeug/_compat.py
@@ -0,0 +1,219 @@
+# flake8: noqa
+# This whole file is full of lint errors
+import functools
+import operator
+import sys
+
+try:
+    import builtins
+except ImportError:
+    import __builtin__ as builtins
+
+
+PY2 = sys.version_info[0] == 2
+WIN = sys.platform.startswith("win")
+
+_identity = lambda x: x
+
+if PY2:
+    unichr = unichr
+    text_type = unicode
+    string_types = (str, unicode)
+    integer_types = (int, long)
+
+    iterkeys = lambda d, *args, **kwargs: d.iterkeys(*args, **kwargs)
+    itervalues = lambda d, *args, **kwargs: d.itervalues(*args, **kwargs)
+    iteritems = lambda d, *args, **kwargs: d.iteritems(*args, **kwargs)
+
+    iterlists = lambda d, *args, **kwargs: d.iterlists(*args, **kwargs)
+    iterlistvalues = lambda d, *args, **kwargs: d.iterlistvalues(*args, **kwargs)
+
+    int_to_byte = chr
+    iter_bytes = iter
+
+    import collections as collections_abc
+
+    exec("def reraise(tp, value, tb=None):\n raise tp, value, tb")
+
+    def fix_tuple_repr(obj):
+        def __repr__(self):
+            cls = self.__class__
+            return "%s(%s)" % (
+                cls.__name__,
+                ", ".join(
+                    "%s=%r" % (field, self[index])
+                    for index, field in enumerate(cls._fields)
+                ),
+            )
+
+        obj.__repr__ = __repr__
+        return obj
+
+    def implements_iterator(cls):
+        cls.next = cls.__next__
+        del cls.__next__
+        return cls
+
+    def implements_to_string(cls):
+        cls.__unicode__ = cls.__str__
+        cls.__str__ = lambda x: x.__unicode__().encode("utf-8")
+        return cls
+
+    def native_string_result(func):
+        def wrapper(*args, **kwargs):
+            return func(*args, **kwargs).encode("utf-8")
+
+        return functools.update_wrapper(wrapper, func)
+
+    def implements_bool(cls):
+        cls.__nonzero__ = cls.__bool__
+        del cls.__bool__
+        return cls
+
+    from itertools import imap, izip, ifilter
+
+    range_type = xrange
+
+    from StringIO import StringIO
+    from cStringIO import StringIO as BytesIO
+
+    NativeStringIO = BytesIO
+
+    def make_literal_wrapper(reference):
+        return _identity
+
+    def normalize_string_tuple(tup):
+        """Normalizes a string tuple to a common type. Following Python 2
+        rules, upgrades to unicode are implicit.
+        """
+        if any(isinstance(x, text_type) for x in tup):
+            return tuple(to_unicode(x) for x in tup)
+        return tup
+
+    def try_coerce_native(s):
+        """Try to coerce a unicode string to native if possible. Otherwise,
+        leave it as unicode.
+        """
+        try:
+            return to_native(s)
+        except UnicodeError:
+            return s
+
+    wsgi_get_bytes = _identity
+
+    def wsgi_decoding_dance(s, charset="utf-8", errors="replace"):
+        return s.decode(charset, errors)
+
+    def wsgi_encoding_dance(s, charset="utf-8", errors="replace"):
+        if isinstance(s, bytes):
+            return s
+        return s.encode(charset, errors)
+
+    def to_bytes(x, charset=sys.getdefaultencoding(), errors="strict"):
+        if x is None:
+            return None
+        if isinstance(x, (bytes, bytearray, buffer)):
+            return bytes(x)
+        if isinstance(x, unicode):
+            return x.encode(charset, errors)
+        raise TypeError("Expected bytes")
+
+    def to_native(x, charset=sys.getdefaultencoding(), errors="strict"):
+        if x is None or isinstance(x, str):
+            return x
+        return x.encode(charset, errors)
+
+
+else:
+    unichr = chr
+    text_type = str
+    string_types = (str,)
+    integer_types = (int,)
+
+    iterkeys = lambda d, *args, **kwargs: iter(d.keys(*args, **kwargs))
+    itervalues = lambda d, *args, **kwargs: iter(d.values(*args, **kwargs))
+    iteritems = lambda d, *args, **kwargs: iter(d.items(*args, **kwargs))
+
+    iterlists = lambda d, *args, **kwargs: iter(d.lists(*args, **kwargs))
+    iterlistvalues = lambda d, *args, **kwargs: iter(d.listvalues(*args, **kwargs))
+
+    int_to_byte = operator.methodcaller("to_bytes", 1, "big")
+    iter_bytes = functools.partial(map, int_to_byte)
+
+    import collections.abc as collections_abc
+
+    def reraise(tp, value, tb=None):
+        if value.__traceback__ is not tb:
+            raise value.with_traceback(tb)
+        raise value
+
+    fix_tuple_repr = _identity
+    implements_iterator = _identity
+    implements_to_string = _identity
+    implements_bool = _identity
+    native_string_result = _identity
+    imap = map
+    izip = zip
+    ifilter = filter
+    range_type = range
+
+    from io import StringIO, BytesIO
+
+    NativeStringIO = StringIO
+
+    _latin1_encode = operator.methodcaller("encode", "latin1")
+
+    def make_literal_wrapper(reference):
+        if isinstance(reference, text_type):
+            return _identity
+        return _latin1_encode
+
+    def normalize_string_tuple(tup):
+        """Ensures that all types in the tuple are either strings
+        or bytes.
+        """
+        tupiter = iter(tup)
+        is_text = isinstance(next(tupiter, None), text_type)
+        for arg in tupiter:
+            if isinstance(arg, text_type) != is_text:
+                raise TypeError(
+                    "Cannot mix str and bytes arguments (got %s)" % repr(tup)
+                )
+        return tup
+
+    try_coerce_native = _identity
+    wsgi_get_bytes = _latin1_encode
+
+    def wsgi_decoding_dance(s, charset="utf-8", errors="replace"):
+        return s.encode("latin1").decode(charset, errors)
+
+    def wsgi_encoding_dance(s, charset="utf-8", errors="replace"):
+        if isinstance(s, text_type):
+            s = s.encode(charset)
+        return s.decode("latin1", errors)
+
+    def to_bytes(x, charset=sys.getdefaultencoding(), errors="strict"):
+        if x is None:
+            return None
+        if isinstance(x, (bytes, bytearray, memoryview)):  # noqa
+            return bytes(x)
+        if isinstance(x, str):
+            return x.encode(charset, errors)
+        raise TypeError("Expected bytes")
+
+    def to_native(x, charset=sys.getdefaultencoding(), errors="strict"):
+        if x is None or isinstance(x, str):
+            return x
+        return x.decode(charset, errors)
+
+
+def to_unicode(
+    x, charset=sys.getdefaultencoding(), errors="strict", allow_none_charset=False
+):
+    if x is None:
+        return None
+    if not isinstance(x, bytes):
+        return text_type(x)
+    if charset is None and allow_none_charset:
+        return x
+    return x.decode(charset, errors)
diff --git a/python/werkzeug/_internal.py b/python/werkzeug/_internal.py
new file mode 100644
index 0000000..90e3dd9
--- /dev/null
+++ b/python/werkzeug/_internal.py
@@ -0,0 +1,484 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug._internal
+    ~~~~~~~~~~~~~~~~~~
+
+    This module provides internally used helpers and constants.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import inspect
+import logging
+import re
+import string
+from datetime import date
+from datetime import datetime
+from itertools import chain
+from weakref import WeakKeyDictionary
+
+from ._compat import int_to_byte
+from ._compat import integer_types
+from ._compat import iter_bytes
+from ._compat import range_type
+from ._compat import text_type
+
+
+_logger = None
+_signature_cache = WeakKeyDictionary()
+_epoch_ord = date(1970, 1, 1).toordinal()
+_cookie_params = {
+    b"expires",
+    b"path",
+    b"comment",
+    b"max-age",
+    b"secure",
+    b"httponly",
+    b"version",
+}
+_legal_cookie_chars = (
+    string.ascii_letters + string.digits + u"/=!#$%&'*+-.^_`|~:"
+).encode("ascii")
+
+_cookie_quoting_map = {b",": b"\\054", b";": b"\\073", b'"': b'\\"', b"\\": b"\\\\"}
+for _i in chain(range_type(32), range_type(127, 256)):
+    _cookie_quoting_map[int_to_byte(_i)] = ("\\%03o" % _i).encode("latin1")
+
+_octal_re = re.compile(br"\\[0-3][0-7][0-7]")
+_quote_re = re.compile(br"[\\].")
+_legal_cookie_chars_re = br"[\w\d!#%&\'~_`><@,:/\$\*\+\-\.\^\|\)\(\?\}\{\=]"
+_cookie_re = re.compile(
+    br"""
+    (?P<key>[^=;]+)
+    (?:\s*=\s*
+        (?P<val>
+            "(?:[^\\"]|\\.)*" |
+             (?:.*?)
+        )
+    )?
+    \s*;
+""",
+    flags=re.VERBOSE,
+)
+
+
+class _Missing(object):
+    def __repr__(self):
+        return "no value"
+
+    def __reduce__(self):
+        return "_missing"
+
+
+_missing = _Missing()
+
+
+def _get_environ(obj):
+    env = getattr(obj, "environ", obj)
+    assert isinstance(env, dict), (
+        "%r is not a WSGI environment (has to be a dict)" % type(obj).__name__
+    )
+    return env
+
+
+def _has_level_handler(logger):
+    """Check if there is a handler in the logging chain that will handle
+    the given logger's effective level.
+    """
+    level = logger.getEffectiveLevel()
+    current = logger
+
+    while current:
+        if any(handler.level <= level for handler in current.handlers):
+            return True
+
+        if not current.propagate:
+            break
+
+        current = current.parent
+
+    return False
+
+
+def _log(type, message, *args, **kwargs):
+    """Log a message to the 'werkzeug' logger.
+
+    The logger is created the first time it is needed. If there is no
+    level set, it is set to :data:`logging.INFO`. If there is no handler
+    for the logger's effective level, a :class:`logging.StreamHandler`
+    is added.
+    """
+    global _logger
+
+    if _logger is None:
+        _logger = logging.getLogger("werkzeug")
+
+        if _logger.level == logging.NOTSET:
+            _logger.setLevel(logging.INFO)
+
+        if not _has_level_handler(_logger):
+            _logger.addHandler(logging.StreamHandler())
+
+    getattr(_logger, type)(message.rstrip(), *args, **kwargs)
+
+
+def _parse_signature(func):
+    """Return a signature object for the function."""
+    if hasattr(func, "im_func"):
+        func = func.im_func
+
+    # if we have a cached validator for this function, return it
+    parse = _signature_cache.get(func)
+    if parse is not None:
+        return parse
+
+    # inspect the function signature and collect all the information
+    if hasattr(inspect, "getfullargspec"):
+        tup = inspect.getfullargspec(func)
+    else:
+        tup = inspect.getargspec(func)
+    positional, vararg_var, kwarg_var, defaults = tup[:4]
+    defaults = defaults or ()
+    arg_count = len(positional)
+    arguments = []
+    for idx, name in enumerate(positional):
+        if isinstance(name, list):
+            raise TypeError(
+                "cannot parse functions that unpack tuples in the function signature"
+            )
+        try:
+            default = defaults[idx - arg_count]
+        except IndexError:
+            param = (name, False, None)
+        else:
+            param = (name, True, default)
+        arguments.append(param)
+    arguments = tuple(arguments)
+
+    def parse(args, kwargs):
+        new_args = []
+        missing = []
+        extra = {}
+
+        # consume as many arguments as positional as possible
+        for idx, (name, has_default, default) in enumerate(arguments):
+            try:
+                new_args.append(args[idx])
+            except IndexError:
+                try:
+                    new_args.append(kwargs.pop(name))
+                except KeyError:
+                    if has_default:
+                        new_args.append(default)
+                    else:
+                        missing.append(name)
+            else:
+                if name in kwargs:
+                    extra[name] = kwargs.pop(name)
+
+        # handle extra arguments
+        extra_positional = args[arg_count:]
+        if vararg_var is not None:
+            new_args.extend(extra_positional)
+            extra_positional = ()
+        if kwargs and kwarg_var is None:
+            extra.update(kwargs)
+            kwargs = {}
+
+        return (
+            new_args,
+            kwargs,
+            missing,
+            extra,
+            extra_positional,
+            arguments,
+            vararg_var,
+            kwarg_var,
+        )
+
+    _signature_cache[func] = parse
+    return parse
+
+
+def _date_to_unix(arg):
+    """Converts a timetuple, integer or datetime object into the seconds from
+    epoch in utc.
+    """
+    if isinstance(arg, datetime):
+        arg = arg.utctimetuple()
+    elif isinstance(arg, integer_types + (float,)):
+        return int(arg)
+    year, month, day, hour, minute, second = arg[:6]
+    days = date(year, month, 1).toordinal() - _epoch_ord + day - 1
+    hours = days * 24 + hour
+    minutes = hours * 60 + minute
+    seconds = minutes * 60 + second
+    return seconds
+
+
+class _DictAccessorProperty(object):
+    """Baseclass for `environ_property` and `header_property`."""
+
+    read_only = False
+
+    def __init__(
+        self,
+        name,
+        default=None,
+        load_func=None,
+        dump_func=None,
+        read_only=None,
+        doc=None,
+    ):
+        self.name = name
+        self.default = default
+        self.load_func = load_func
+        self.dump_func = dump_func
+        if read_only is not None:
+            self.read_only = read_only
+        self.__doc__ = doc
+
+    def __get__(self, obj, type=None):
+        if obj is None:
+            return self
+        storage = self.lookup(obj)
+        if self.name not in storage:
+            return self.default
+        rv = storage[self.name]
+        if self.load_func is not None:
+            try:
+                rv = self.load_func(rv)
+            except (ValueError, TypeError):
+                rv = self.default
+        return rv
+
+    def __set__(self, obj, value):
+        if self.read_only:
+            raise AttributeError("read only property")
+        if self.dump_func is not None:
+            value = self.dump_func(value)
+        self.lookup(obj)[self.name] = value
+
+    def __delete__(self, obj):
+        if self.read_only:
+            raise AttributeError("read only property")
+        self.lookup(obj).pop(self.name, None)
+
+    def __repr__(self):
+        return "<%s %s>" % (self.__class__.__name__, self.name)
+
+
+def _cookie_quote(b):
+    buf = bytearray()
+    all_legal = True
+    _lookup = _cookie_quoting_map.get
+    _push = buf.extend
+
+    for char in iter_bytes(b):
+        if char not in _legal_cookie_chars:
+            all_legal = False
+            char = _lookup(char, char)
+        _push(char)
+
+    if all_legal:
+        return bytes(buf)
+    return bytes(b'"' + buf + b'"')
+
+
+def _cookie_unquote(b):
+    if len(b) < 2:
+        return b
+    if b[:1] != b'"' or b[-1:] != b'"':
+        return b
+
+    b = b[1:-1]
+
+    i = 0
+    n = len(b)
+    rv = bytearray()
+    _push = rv.extend
+
+    while 0 <= i < n:
+        o_match = _octal_re.search(b, i)
+        q_match = _quote_re.search(b, i)
+        if not o_match and not q_match:
+            rv.extend(b[i:])
+            break
+        j = k = -1
+        if o_match:
+            j = o_match.start(0)
+        if q_match:
+            k = q_match.start(0)
+        if q_match and (not o_match or k < j):
+            _push(b[i:k])
+            _push(b[k + 1 : k + 2])
+            i = k + 2
+        else:
+            _push(b[i:j])
+            rv.append(int(b[j + 1 : j + 4], 8))
+            i = j + 4
+
+    return bytes(rv)
+
+
+def _cookie_parse_impl(b):
+    """Lowlevel cookie parsing facility that operates on bytes."""
+    i = 0
+    n = len(b)
+
+    while i < n:
+        match = _cookie_re.search(b + b";", i)
+        if not match:
+            break
+
+        key = match.group("key").strip()
+        value = match.group("val") or b""
+        i = match.end(0)
+
+        # Ignore parameters.  We have no interest in them.
+        if key.lower() not in _cookie_params:
+            yield _cookie_unquote(key), _cookie_unquote(value)
+
+
+def _encode_idna(domain):
+    # If we're given bytes, make sure they fit into ASCII
+    if not isinstance(domain, text_type):
+        domain.decode("ascii")
+        return domain
+
+    # Otherwise check if it's already ascii, then return
+    try:
+        return domain.encode("ascii")
+    except UnicodeError:
+        pass
+
+    # Otherwise encode each part separately
+    parts = domain.split(".")
+    for idx, part in enumerate(parts):
+        parts[idx] = part.encode("idna")
+    return b".".join(parts)
+
+
+def _decode_idna(domain):
+    # If the input is a string try to encode it to ascii to
+    # do the idna decoding.  if that fails because of an
+    # unicode error, then we already have a decoded idna domain
+    if isinstance(domain, text_type):
+        try:
+            domain = domain.encode("ascii")
+        except UnicodeError:
+            return domain
+
+    # Decode each part separately.  If a part fails, try to
+    # decode it with ascii and silently ignore errors.  This makes
+    # most sense because the idna codec does not have error handling
+    parts = domain.split(b".")
+    for idx, part in enumerate(parts):
+        try:
+            parts[idx] = part.decode("idna")
+        except UnicodeError:
+            parts[idx] = part.decode("ascii", "ignore")
+
+    return ".".join(parts)
+
+
+def _make_cookie_domain(domain):
+    if domain is None:
+        return None
+    domain = _encode_idna(domain)
+    if b":" in domain:
+        domain = domain.split(b":", 1)[0]
+    if b"." in domain:
+        return domain
+    raise ValueError(
+        "Setting 'domain' for a cookie on a server running locally (ex: "
+        "localhost) is not supported by complying browsers. You should "
+        "have something like: '127.0.0.1 localhost dev.localhost' on "
+        "your hosts file and then point your server to run on "
+        "'dev.localhost' and also set 'domain' for 'dev.localhost'"
+    )
+
+
+def _easteregg(app=None):
+    """Like the name says.  But who knows how it works?"""
+
+    def bzzzzzzz(gyver):
+        import base64
+        import zlib
+
+        return zlib.decompress(base64.b64decode(gyver)).decode("ascii")
+
+    gyver = u"\n".join(
+        [
+            x + (77 - len(x)) * u" "
+            for x in bzzzzzzz(
+                b"""
+eJyFlzuOJDkMRP06xRjymKgDJCDQStBYT8BCgK4gTwfQ2fcFs2a2FzvZk+hvlcRvRJD148efHt9m
+9Xz94dRY5hGt1nrYcXx7us9qlcP9HHNh28rz8dZj+q4rynVFFPdlY4zH873NKCexrDM6zxxRymzz
+4QIxzK4bth1PV7+uHn6WXZ5C4ka/+prFzx3zWLMHAVZb8RRUxtFXI5DTQ2n3Hi2sNI+HK43AOWSY
+jmEzE4naFp58PdzhPMdslLVWHTGUVpSxImw+pS/D+JhzLfdS1j7PzUMxij+mc2U0I9zcbZ/HcZxc
+q1QjvvcThMYFnp93agEx392ZdLJWXbi/Ca4Oivl4h/Y1ErEqP+lrg7Xa4qnUKu5UE9UUA4xeqLJ5
+jWlPKJvR2yhRI7xFPdzPuc6adXu6ovwXwRPXXnZHxlPtkSkqWHilsOrGrvcVWXgGP3daXomCj317
+8P2UOw/NnA0OOikZyFf3zZ76eN9QXNwYdD8f8/LdBRFg0BO3bB+Pe/+G8er8tDJv83XTkj7WeMBJ
+v/rnAfdO51d6sFglfi8U7zbnr0u9tyJHhFZNXYfH8Iafv2Oa+DT6l8u9UYlajV/hcEgk1x8E8L/r
+XJXl2SK+GJCxtnyhVKv6GFCEB1OO3f9YWAIEbwcRWv/6RPpsEzOkXURMN37J0PoCSYeBnJQd9Giu
+LxYQJNlYPSo/iTQwgaihbART7Fcyem2tTSCcwNCs85MOOpJtXhXDe0E7zgZJkcxWTar/zEjdIVCk
+iXy87FW6j5aGZhttDBoAZ3vnmlkx4q4mMmCdLtnHkBXFMCReqthSGkQ+MDXLLCpXwBs0t+sIhsDI
+tjBB8MwqYQpLygZ56rRHHpw+OAVyGgaGRHWy2QfXez+ZQQTTBkmRXdV/A9LwH6XGZpEAZU8rs4pE
+1R4FQ3Uwt8RKEtRc0/CrANUoes3EzM6WYcFyskGZ6UTHJWenBDS7h163Eo2bpzqxNE9aVgEM2CqI
+GAJe9Yra4P5qKmta27VjzYdR04Vc7KHeY4vs61C0nbywFmcSXYjzBHdiEjraS7PGG2jHHTpJUMxN
+Jlxr3pUuFvlBWLJGE3GcA1/1xxLcHmlO+LAXbhrXah1tD6Ze+uqFGdZa5FM+3eHcKNaEarutAQ0A
+QMAZHV+ve6LxAwWnXbbSXEG2DmCX5ijeLCKj5lhVFBrMm+ryOttCAeFpUdZyQLAQkA06RLs56rzG
+8MID55vqr/g64Qr/wqwlE0TVxgoiZhHrbY2h1iuuyUVg1nlkpDrQ7Vm1xIkI5XRKLedN9EjzVchu
+jQhXcVkjVdgP2O99QShpdvXWoSwkp5uMwyjt3jiWCqWGSiaaPAzohjPanXVLbM3x0dNskJsaCEyz
+DTKIs+7WKJD4ZcJGfMhLFBf6hlbnNkLEePF8Cx2o2kwmYF4+MzAxa6i+6xIQkswOqGO+3x9NaZX8
+MrZRaFZpLeVTYI9F/djY6DDVVs340nZGmwrDqTCiiqD5luj3OzwpmQCiQhdRYowUYEA3i1WWGwL4
+GCtSoO4XbIPFeKGU13XPkDf5IdimLpAvi2kVDVQbzOOa4KAXMFlpi/hV8F6IDe0Y2reg3PuNKT3i
+RYhZqtkQZqSB2Qm0SGtjAw7RDwaM1roESC8HWiPxkoOy0lLTRFG39kvbLZbU9gFKFRvixDZBJmpi
+Xyq3RE5lW00EJjaqwp/v3EByMSpVZYsEIJ4APaHmVtpGSieV5CALOtNUAzTBiw81GLgC0quyzf6c
+NlWknzJeCsJ5fup2R4d8CYGN77mu5vnO1UqbfElZ9E6cR6zbHjgsr9ly18fXjZoPeDjPuzlWbFwS
+pdvPkhntFvkc13qb9094LL5NrA3NIq3r9eNnop9DizWOqCEbyRBFJTHn6Tt3CG1o8a4HevYh0XiJ
+sR0AVVHuGuMOIfbuQ/OKBkGRC6NJ4u7sbPX8bG/n5sNIOQ6/Y/BX3IwRlTSabtZpYLB85lYtkkgm
+p1qXK3Du2mnr5INXmT/78KI12n11EFBkJHHp0wJyLe9MvPNUGYsf+170maayRoy2lURGHAIapSpQ
+krEDuNoJCHNlZYhKpvw4mspVWxqo415n8cD62N9+EfHrAvqQnINStetek7RY2Urv8nxsnGaZfRr/
+nhXbJ6m/yl1LzYqscDZA9QHLNbdaSTTr+kFg3bC0iYbX/eQy0Bv3h4B50/SGYzKAXkCeOLI3bcAt
+mj2Z/FM1vQWgDynsRwNvrWnJHlespkrp8+vO1jNaibm+PhqXPPv30YwDZ6jApe3wUjFQobghvW9p
+7f2zLkGNv8b191cD/3vs9Q833z8t"""
+            ).splitlines()
+        ]
+    )
+
+    def easteregged(environ, start_response):
+        def injecting_start_response(status, headers, exc_info=None):
+            headers.append(("X-Powered-By", "Werkzeug"))
+            return start_response(status, headers, exc_info)
+
+        if app is not None and environ.get("QUERY_STRING") != "macgybarchakku":
+            return app(environ, injecting_start_response)
+        injecting_start_response("200 OK", [("Content-Type", "text/html")])
+        return [
+            (
+                u"""
+<!DOCTYPE html>
+<html>
+<head>
+<title>About Werkzeug</title>
+<style type="text/css">
+  body { font: 15px Georgia, serif; text-align: center; }
+  a { color: #333; text-decoration: none; }
+  h1 { font-size: 30px; margin: 20px 0 10px 0; }
+  p { margin: 0 0 30px 0; }
+  pre { font: 11px 'Consolas', 'Monaco', monospace; line-height: 0.95; }
+</style>
+</head>
+<body>
+<h1><a href="http://werkzeug.pocoo.org/">Werkzeug</a></h1>
+<p>the Swiss Army knife of Python web development.</p>
+<pre>%s\n\n\n</pre>
+</body>
+</html>"""
+                % gyver
+            ).encode("latin1")
+        ]
+
+    return easteregged
diff --git a/python/werkzeug/_reloader.py b/python/werkzeug/_reloader.py
new file mode 100644
index 0000000..f06a63d
--- /dev/null
+++ b/python/werkzeug/_reloader.py
@@ -0,0 +1,334 @@
+import os
+import subprocess
+import sys
+import threading
+import time
+from itertools import chain
+
+from ._compat import iteritems
+from ._compat import PY2
+from ._compat import text_type
+from ._internal import _log
+
+
+def _iter_module_files():
+    """This iterates over all relevant Python files.  It goes through all
+    loaded files from modules, all files in folders of already loaded modules
+    as well as all files reachable through a package.
+    """
+    # The list call is necessary on Python 3 in case the module
+    # dictionary modifies during iteration.
+    for module in list(sys.modules.values()):
+        if module is None:
+            continue
+        filename = getattr(module, "__file__", None)
+        if filename:
+            if os.path.isdir(filename) and os.path.exists(
+                os.path.join(filename, "__init__.py")
+            ):
+                filename = os.path.join(filename, "__init__.py")
+
+            old = None
+            while not os.path.isfile(filename):
+                old = filename
+                filename = os.path.dirname(filename)
+                if filename == old:
+                    break
+            else:
+                if filename[-4:] in (".pyc", ".pyo"):
+                    filename = filename[:-1]
+                yield filename
+
+
+def _find_observable_paths(extra_files=None):
+    """Finds all paths that should be observed."""
+    rv = set(
+        os.path.dirname(os.path.abspath(x)) if os.path.isfile(x) else os.path.abspath(x)
+        for x in sys.path
+    )
+
+    for filename in extra_files or ():
+        rv.add(os.path.dirname(os.path.abspath(filename)))
+
+    for module in list(sys.modules.values()):
+        fn = getattr(module, "__file__", None)
+        if fn is None:
+            continue
+        fn = os.path.abspath(fn)
+        rv.add(os.path.dirname(fn))
+
+    return _find_common_roots(rv)
+
+
+def _get_args_for_reloading():
+    """Returns the executable. This contains a workaround for windows
+    if the executable is incorrectly reported to not have the .exe
+    extension which can cause bugs on reloading.  This also contains
+    a workaround for linux where the file is executable (possibly with
+    a program other than python)
+    """
+    rv = [sys.executable]
+    py_script = os.path.abspath(sys.argv[0])
+    args = sys.argv[1:]
+    # Need to look at main module to determine how it was executed.
+    __main__ = sys.modules["__main__"]
+
+    if __main__.__package__ is None:
+        # Executed a file, like "python app.py".
+        if os.name == "nt":
+            # Windows entry points have ".exe" extension and should be
+            # called directly.
+            if not os.path.exists(py_script) and os.path.exists(py_script + ".exe"):
+                py_script += ".exe"
+
+            if (
+                os.path.splitext(rv[0])[1] == ".exe"
+                and os.path.splitext(py_script)[1] == ".exe"
+            ):
+                rv.pop(0)
+
+        elif os.path.isfile(py_script) and os.access(py_script, os.X_OK):
+            # The file is marked as executable. Nix adds a wrapper that
+            # shouldn't be called with the Python executable.
+            rv.pop(0)
+
+        rv.append(py_script)
+    else:
+        # Executed a module, like "python -m werkzeug.serving".
+        if sys.argv[0] == "-m":
+            # Flask works around previous behavior by putting
+            # "-m flask" in sys.argv.
+            # TODO remove this once Flask no longer misbehaves
+            args = sys.argv
+        else:
+            py_module = __main__.__package__
+            name = os.path.splitext(os.path.basename(py_script))[0]
+
+            if name != "__main__":
+                py_module += "." + name
+
+            rv.extend(("-m", py_module.lstrip(".")))
+
+    rv.extend(args)
+    return rv
+
+
+def _find_common_roots(paths):
+    """Out of some paths it finds the common roots that need monitoring."""
+    paths = [x.split(os.path.sep) for x in paths]
+    root = {}
+    for chunks in sorted(paths, key=len, reverse=True):
+        node = root
+        for chunk in chunks:
+            node = node.setdefault(chunk, {})
+        node.clear()
+
+    rv = set()
+
+    def _walk(node, path):
+        for prefix, child in iteritems(node):
+            _walk(child, path + (prefix,))
+        if not node:
+            rv.add("/".join(path))
+
+    _walk(root, ())
+    return rv
+
+
+class ReloaderLoop(object):
+    name = None
+
+    # monkeypatched by testsuite. wrapping with `staticmethod` is required in
+    # case time.sleep has been replaced by a non-c function (e.g. by
+    # `eventlet.monkey_patch`) before we get here
+    _sleep = staticmethod(time.sleep)
+
+    def __init__(self, extra_files=None, interval=1):
+        self.extra_files = set(os.path.abspath(x) for x in extra_files or ())
+        self.interval = interval
+
+    def run(self):
+        pass
+
+    def restart_with_reloader(self):
+        """Spawn a new Python interpreter with the same arguments as this one,
+        but running the reloader thread.
+        """
+        while 1:
+            _log("info", " * Restarting with %s" % self.name)
+            args = _get_args_for_reloading()
+
+            # a weird bug on windows. sometimes unicode strings end up in the
+            # environment and subprocess.call does not like this, encode them
+            # to latin1 and continue.
+            if os.name == "nt" and PY2:
+                new_environ = {}
+                for key, value in iteritems(os.environ):
+                    if isinstance(key, text_type):
+                        key = key.encode("iso-8859-1")
+                    if isinstance(value, text_type):
+                        value = value.encode("iso-8859-1")
+                    new_environ[key] = value
+            else:
+                new_environ = os.environ.copy()
+
+            new_environ["WERKZEUG_RUN_MAIN"] = "true"
+            exit_code = subprocess.call(args, env=new_environ, close_fds=False)
+            if exit_code != 3:
+                return exit_code
+
+    def trigger_reload(self, filename):
+        self.log_reload(filename)
+        sys.exit(3)
+
+    def log_reload(self, filename):
+        filename = os.path.abspath(filename)
+        _log("info", " * Detected change in %r, reloading" % filename)
+
+
+class StatReloaderLoop(ReloaderLoop):
+    name = "stat"
+
+    def run(self):
+        mtimes = {}
+        while 1:
+            for filename in chain(_iter_module_files(), self.extra_files):
+                try:
+                    mtime = os.stat(filename).st_mtime
+                except OSError:
+                    continue
+
+                old_time = mtimes.get(filename)
+                if old_time is None:
+                    mtimes[filename] = mtime
+                    continue
+                elif mtime > old_time:
+                    self.trigger_reload(filename)
+            self._sleep(self.interval)
+
+
+class WatchdogReloaderLoop(ReloaderLoop):
+    def __init__(self, *args, **kwargs):
+        ReloaderLoop.__init__(self, *args, **kwargs)
+        from watchdog.observers import Observer
+        from watchdog.events import FileSystemEventHandler
+
+        self.observable_paths = set()
+
+        def _check_modification(filename):
+            if filename in self.extra_files:
+                self.trigger_reload(filename)
+            dirname = os.path.dirname(filename)
+            if dirname.startswith(tuple(self.observable_paths)):
+                if filename.endswith((".pyc", ".pyo", ".py")):
+                    self.trigger_reload(filename)
+
+        class _CustomHandler(FileSystemEventHandler):
+            def on_created(self, event):
+                _check_modification(event.src_path)
+
+            def on_modified(self, event):
+                _check_modification(event.src_path)
+
+            def on_moved(self, event):
+                _check_modification(event.src_path)
+                _check_modification(event.dest_path)
+
+            def on_deleted(self, event):
+                _check_modification(event.src_path)
+
+        reloader_name = Observer.__name__.lower()
+        if reloader_name.endswith("observer"):
+            reloader_name = reloader_name[:-8]
+        reloader_name += " reloader"
+
+        self.name = reloader_name
+
+        self.observer_class = Observer
+        self.event_handler = _CustomHandler()
+        self.should_reload = False
+
+    def trigger_reload(self, filename):
+        # This is called inside an event handler, which means throwing
+        # SystemExit has no effect.
+        # https://github.com/gorakhargosh/watchdog/issues/294
+        self.should_reload = True
+        self.log_reload(filename)
+
+    def run(self):
+        watches = {}
+        observer = self.observer_class()
+        observer.start()
+
+        try:
+            while not self.should_reload:
+                to_delete = set(watches)
+                paths = _find_observable_paths(self.extra_files)
+                for path in paths:
+                    if path not in watches:
+                        try:
+                            watches[path] = observer.schedule(
+                                self.event_handler, path, recursive=True
+                            )
+                        except OSError:
+                            # Clear this path from list of watches We don't want
+                            # the same error message showing again in the next
+                            # iteration.
+                            watches[path] = None
+                    to_delete.discard(path)
+                for path in to_delete:
+                    watch = watches.pop(path, None)
+                    if watch is not None:
+                        observer.unschedule(watch)
+                self.observable_paths = paths
+                self._sleep(self.interval)
+        finally:
+            observer.stop()
+            observer.join()
+
+        sys.exit(3)
+
+
+reloader_loops = {"stat": StatReloaderLoop, "watchdog": WatchdogReloaderLoop}
+
+try:
+    __import__("watchdog.observers")
+except ImportError:
+    reloader_loops["auto"] = reloader_loops["stat"]
+else:
+    reloader_loops["auto"] = reloader_loops["watchdog"]
+
+
+def ensure_echo_on():
+    """Ensure that echo mode is enabled. Some tools such as PDB disable
+    it which causes usability issues after reload."""
+    # tcgetattr will fail if stdin isn't a tty
+    if not sys.stdin.isatty():
+        return
+    try:
+        import termios
+    except ImportError:
+        return
+    attributes = termios.tcgetattr(sys.stdin)
+    if not attributes[3] & termios.ECHO:
+        attributes[3] |= termios.ECHO
+        termios.tcsetattr(sys.stdin, termios.TCSANOW, attributes)
+
+
+def run_with_reloader(main_func, extra_files=None, interval=1, reloader_type="auto"):
+    """Run the given function in an independent python interpreter."""
+    import signal
+
+    reloader = reloader_loops[reloader_type](extra_files, interval)
+    signal.signal(signal.SIGTERM, lambda *args: sys.exit(0))
+    try:
+        if os.environ.get("WERKZEUG_RUN_MAIN") == "true":
+            ensure_echo_on()
+            t = threading.Thread(target=main_func, args=())
+            t.setDaemon(True)
+            t.start()
+            reloader.run()
+        else:
+            sys.exit(reloader.restart_with_reloader())
+    except KeyboardInterrupt:
+        pass
diff --git a/python/werkzeug/contrib/__init__.py b/python/werkzeug/contrib/__init__.py
new file mode 100644
index 0000000..0e741f0
--- /dev/null
+++ b/python/werkzeug/contrib/__init__.py
@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.contrib
+    ~~~~~~~~~~~~~~~~
+
+    Contains user-submitted code that other users may find useful, but which
+    is not part of the Werkzeug core.  Anyone can write code for inclusion in
+    the `contrib` package.  All modules in this package are distributed as an
+    add-on library and thus are not part of Werkzeug itself.
+
+    This file itself is mostly for informational purposes and to tell the
+    Python interpreter that `contrib` is a package.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
diff --git a/python/werkzeug/contrib/atom.py b/python/werkzeug/contrib/atom.py
new file mode 100644
index 0000000..d079d2b
--- /dev/null
+++ b/python/werkzeug/contrib/atom.py
@@ -0,0 +1,362 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.contrib.atom
+    ~~~~~~~~~~~~~~~~~~~~~
+
+    This module provides a class called :class:`AtomFeed` which can be
+    used to generate feeds in the Atom syndication format (see :rfc:`4287`).
+
+    Example::
+
+        def atom_feed(request):
+            feed = AtomFeed("My Blog", feed_url=request.url,
+                            url=request.host_url,
+                            subtitle="My example blog for a feed test.")
+            for post in Post.query.limit(10).all():
+                feed.add(post.title, post.body, content_type='html',
+                         author=post.author, url=post.url, id=post.uid,
+                         updated=post.last_update, published=post.pub_date)
+            return feed.get_response()
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import warnings
+from datetime import datetime
+
+from .._compat import implements_to_string
+from .._compat import string_types
+from ..utils import escape
+from ..wrappers import BaseResponse
+
+warnings.warn(
+    "'werkzeug.contrib.atom' is deprecated as of version 0.15 and will"
+    " be removed in version 1.0.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+XHTML_NAMESPACE = "http://www.w3.org/1999/xhtml"
+
+
+def _make_text_block(name, content, content_type=None):
+    """Helper function for the builder that creates an XML text block."""
+    if content_type == "xhtml":
+        return u'<%s type="xhtml"><div xmlns="%s">%s</div></%s>\n' % (
+            name,
+            XHTML_NAMESPACE,
+            content,
+            name,
+        )
+    if not content_type:
+        return u"<%s>%s</%s>\n" % (name, escape(content), name)
+    return u'<%s type="%s">%s</%s>\n' % (name, content_type, escape(content), name)
+
+
+def format_iso8601(obj):
+    """Format a datetime object for iso8601"""
+    iso8601 = obj.isoformat()
+    if obj.tzinfo:
+        return iso8601
+    return iso8601 + "Z"
+
+
+@implements_to_string
+class AtomFeed(object):
+
+    """A helper class that creates Atom feeds.
+
+    :param title: the title of the feed. Required.
+    :param title_type: the type attribute for the title element.  One of
+                       ``'html'``, ``'text'`` or ``'xhtml'``.
+    :param url: the url for the feed (not the url *of* the feed)
+    :param id: a globally unique id for the feed.  Must be an URI.  If
+               not present the `feed_url` is used, but one of both is
+               required.
+    :param updated: the time the feed was modified the last time.  Must
+                    be a :class:`datetime.datetime` object.  If not
+                    present the latest entry's `updated` is used.
+                    Treated as UTC if naive datetime.
+    :param feed_url: the URL to the feed.  Should be the URL that was
+                     requested.
+    :param author: the author of the feed.  Must be either a string (the
+                   name) or a dict with name (required) and uri or
+                   email (both optional).  Can be a list of (may be
+                   mixed, too) strings and dicts, too, if there are
+                   multiple authors. Required if not every entry has an
+                   author element.
+    :param icon: an icon for the feed.
+    :param logo: a logo for the feed.
+    :param rights: copyright information for the feed.
+    :param rights_type: the type attribute for the rights element.  One of
+                        ``'html'``, ``'text'`` or ``'xhtml'``.  Default is
+                        ``'text'``.
+    :param subtitle: a short description of the feed.
+    :param subtitle_type: the type attribute for the subtitle element.
+                          One of ``'text'``, ``'html'``, ``'text'``
+                          or ``'xhtml'``.  Default is ``'text'``.
+    :param links: additional links.  Must be a list of dictionaries with
+                  href (required) and rel, type, hreflang, title, length
+                  (all optional)
+    :param generator: the software that generated this feed.  This must be
+                      a tuple in the form ``(name, url, version)``.  If
+                      you don't want to specify one of them, set the item
+                      to `None`.
+    :param entries: a list with the entries for the feed. Entries can also
+                    be added later with :meth:`add`.
+
+    For more information on the elements see
+    http://www.atomenabled.org/developers/syndication/
+
+    Everywhere where a list is demanded, any iterable can be used.
+    """
+
+    default_generator = ("Werkzeug", None, None)
+
+    def __init__(self, title=None, entries=None, **kwargs):
+        self.title = title
+        self.title_type = kwargs.get("title_type", "text")
+        self.url = kwargs.get("url")
+        self.feed_url = kwargs.get("feed_url", self.url)
+        self.id = kwargs.get("id", self.feed_url)
+        self.updated = kwargs.get("updated")
+        self.author = kwargs.get("author", ())
+        self.icon = kwargs.get("icon")
+        self.logo = kwargs.get("logo")
+        self.rights = kwargs.get("rights")
+        self.rights_type = kwargs.get("rights_type")
+        self.subtitle = kwargs.get("subtitle")
+        self.subtitle_type = kwargs.get("subtitle_type", "text")
+        self.generator = kwargs.get("generator")
+        if self.generator is None:
+            self.generator = self.default_generator
+        self.links = kwargs.get("links", [])
+        self.entries = list(entries) if entries else []
+
+        if not hasattr(self.author, "__iter__") or isinstance(
+            self.author, string_types + (dict,)
+        ):
+            self.author = [self.author]
+        for i, author in enumerate(self.author):
+            if not isinstance(author, dict):
+                self.author[i] = {"name": author}
+
+        if not self.title:
+            raise ValueError("title is required")
+        if not self.id:
+            raise ValueError("id is required")
+        for author in self.author:
+            if "name" not in author:
+                raise TypeError("author must contain at least a name")
+
+    def add(self, *args, **kwargs):
+        """Add a new entry to the feed.  This function can either be called
+        with a :class:`FeedEntry` or some keyword and positional arguments
+        that are forwarded to the :class:`FeedEntry` constructor.
+        """
+        if len(args) == 1 and not kwargs and isinstance(args[0], FeedEntry):
+            self.entries.append(args[0])
+        else:
+            kwargs["feed_url"] = self.feed_url
+            self.entries.append(FeedEntry(*args, **kwargs))
+
+    def __repr__(self):
+        return "<%s %r (%d entries)>" % (
+            self.__class__.__name__,
+            self.title,
+            len(self.entries),
+        )
+
+    def generate(self):
+        """Return a generator that yields pieces of XML."""
+        # atom demands either an author element in every entry or a global one
+        if not self.author:
+            if any(not e.author for e in self.entries):
+                self.author = ({"name": "Unknown author"},)
+
+        if not self.updated:
+            dates = sorted([entry.updated for entry in self.entries])
+            self.updated = dates[-1] if dates else datetime.utcnow()
+
+        yield u'<?xml version="1.0" encoding="utf-8"?>\n'
+        yield u'<feed xmlns="http://www.w3.org/2005/Atom">\n'
+        yield "  " + _make_text_block("title", self.title, self.title_type)
+        yield u"  <id>%s</id>\n" % escape(self.id)
+        yield u"  <updated>%s</updated>\n" % format_iso8601(self.updated)
+        if self.url:
+            yield u'  <link href="%s" />\n' % escape(self.url)
+        if self.feed_url:
+            yield u'  <link href="%s" rel="self" />\n' % escape(self.feed_url)
+        for link in self.links:
+            yield u"  <link %s/>\n" % "".join(
+                '%s="%s" ' % (k, escape(link[k])) for k in link
+            )
+        for author in self.author:
+            yield u"  <author>\n"
+            yield u"    <name>%s</name>\n" % escape(author["name"])
+            if "uri" in author:
+                yield u"    <uri>%s</uri>\n" % escape(author["uri"])
+            if "email" in author:
+                yield "    <email>%s</email>\n" % escape(author["email"])
+            yield "  </author>\n"
+        if self.subtitle:
+            yield "  " + _make_text_block("subtitle", self.subtitle, self.subtitle_type)
+        if self.icon:
+            yield u"  <icon>%s</icon>\n" % escape(self.icon)
+        if self.logo:
+            yield u"  <logo>%s</logo>\n" % escape(self.logo)
+        if self.rights:
+            yield "  " + _make_text_block("rights", self.rights, self.rights_type)
+        generator_name, generator_url, generator_version = self.generator
+        if generator_name or generator_url or generator_version:
+            tmp = [u"  <generator"]
+            if generator_url:
+                tmp.append(u' uri="%s"' % escape(generator_url))
+            if generator_version:
+                tmp.append(u' version="%s"' % escape(generator_version))
+            tmp.append(u">%s</generator>\n" % escape(generator_name))
+            yield u"".join(tmp)
+        for entry in self.entries:
+            for line in entry.generate():
+                yield u"  " + line
+        yield u"</feed>\n"
+
+    def to_string(self):
+        """Convert the feed into a string."""
+        return u"".join(self.generate())
+
+    def get_response(self):
+        """Return a response object for the feed."""
+        return BaseResponse(self.to_string(), mimetype="application/atom+xml")
+
+    def __call__(self, environ, start_response):
+        """Use the class as WSGI response object."""
+        return self.get_response()(environ, start_response)
+
+    def __str__(self):
+        return self.to_string()
+
+
+@implements_to_string
+class FeedEntry(object):
+
+    """Represents a single entry in a feed.
+
+    :param title: the title of the entry. Required.
+    :param title_type: the type attribute for the title element.  One of
+                       ``'html'``, ``'text'`` or ``'xhtml'``.
+    :param content: the content of the entry.
+    :param content_type: the type attribute for the content element.  One
+                         of ``'html'``, ``'text'`` or ``'xhtml'``.
+    :param summary: a summary of the entry's content.
+    :param summary_type: the type attribute for the summary element.  One
+                         of ``'html'``, ``'text'`` or ``'xhtml'``.
+    :param url: the url for the entry.
+    :param id: a globally unique id for the entry.  Must be an URI.  If
+               not present the URL is used, but one of both is required.
+    :param updated: the time the entry was modified the last time.  Must
+                    be a :class:`datetime.datetime` object.  Treated as
+                    UTC if naive datetime. Required.
+    :param author: the author of the entry.  Must be either a string (the
+                   name) or a dict with name (required) and uri or
+                   email (both optional).  Can be a list of (may be
+                   mixed, too) strings and dicts, too, if there are
+                   multiple authors. Required if the feed does not have an
+                   author element.
+    :param published: the time the entry was initially published.  Must
+                      be a :class:`datetime.datetime` object.  Treated as
+                      UTC if naive datetime.
+    :param rights: copyright information for the entry.
+    :param rights_type: the type attribute for the rights element.  One of
+                        ``'html'``, ``'text'`` or ``'xhtml'``.  Default is
+                        ``'text'``.
+    :param links: additional links.  Must be a list of dictionaries with
+                  href (required) and rel, type, hreflang, title, length
+                  (all optional)
+    :param categories: categories for the entry. Must be a list of dictionaries
+                       with term (required), scheme and label (all optional)
+    :param xml_base: The xml base (url) for this feed item.  If not provided
+                     it will default to the item url.
+
+    For more information on the elements see
+    http://www.atomenabled.org/developers/syndication/
+
+    Everywhere where a list is demanded, any iterable can be used.
+    """
+
+    def __init__(self, title=None, content=None, feed_url=None, **kwargs):
+        self.title = title
+        self.title_type = kwargs.get("title_type", "text")
+        self.content = content
+        self.content_type = kwargs.get("content_type", "html")
+        self.url = kwargs.get("url")
+        self.id = kwargs.get("id", self.url)
+        self.updated = kwargs.get("updated")
+        self.summary = kwargs.get("summary")
+        self.summary_type = kwargs.get("summary_type", "html")
+        self.author = kwargs.get("author", ())
+        self.published = kwargs.get("published")
+        self.rights = kwargs.get("rights")
+        self.links = kwargs.get("links", [])
+        self.categories = kwargs.get("categories", [])
+        self.xml_base = kwargs.get("xml_base", feed_url)
+
+        if not hasattr(self.author, "__iter__") or isinstance(
+            self.author, string_types + (dict,)
+        ):
+            self.author = [self.author]
+        for i, author in enumerate(self.author):
+            if not isinstance(author, dict):
+                self.author[i] = {"name": author}
+
+        if not self.title:
+            raise ValueError("title is required")
+        if not self.id:
+            raise ValueError("id is required")
+        if not self.updated:
+            raise ValueError("updated is required")
+
+    def __repr__(self):
+        return "<%s %r>" % (self.__class__.__name__, self.title)
+
+    def generate(self):
+        """Yields pieces of ATOM XML."""
+        base = ""
+        if self.xml_base:
+            base = ' xml:base="%s"' % escape(self.xml_base)
+        yield u"<entry%s>\n" % base
+        yield u"  " + _make_text_block("title", self.title, self.title_type)
+        yield u"  <id>%s</id>\n" % escape(self.id)
+        yield u"  <updated>%s</updated>\n" % format_iso8601(self.updated)
+        if self.published:
+            yield u"  <published>%s</published>\n" % format_iso8601(self.published)
+        if self.url:
+            yield u'  <link href="%s" />\n' % escape(self.url)
+        for author in self.author:
+            yield u"  <author>\n"
+            yield u"    <name>%s</name>\n" % escape(author["name"])
+            if "uri" in author:
+                yield u"    <uri>%s</uri>\n" % escape(author["uri"])
+            if "email" in author:
+                yield u"    <email>%s</email>\n" % escape(author["email"])
+            yield u"  </author>\n"
+        for link in self.links:
+            yield u"  <link %s/>\n" % "".join(
+                '%s="%s" ' % (k, escape(link[k])) for k in link
+            )
+        for category in self.categories:
+            yield u"  <category %s/>\n" % "".join(
+                '%s="%s" ' % (k, escape(category[k])) for k in category
+            )
+        if self.summary:
+            yield u"  " + _make_text_block("summary", self.summary, self.summary_type)
+        if self.content:
+            yield u"  " + _make_text_block("content", self.content, self.content_type)
+        yield u"</entry>\n"
+
+    def to_string(self):
+        """Convert the feed item into a unicode object."""
+        return u"".join(self.generate())
+
+    def __str__(self):
+        return self.to_string()
diff --git a/python/werkzeug/contrib/cache.py b/python/werkzeug/contrib/cache.py
new file mode 100644
index 0000000..79c749b
--- /dev/null
+++ b/python/werkzeug/contrib/cache.py
@@ -0,0 +1,933 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.contrib.cache
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    The main problem with dynamic Web sites is, well, they're dynamic.  Each
+    time a user requests a page, the webserver executes a lot of code, queries
+    the database, renders templates until the visitor gets the page he sees.
+
+    This is a lot more expensive than just loading a file from the file system
+    and sending it to the visitor.
+
+    For most Web applications, this overhead isn't a big deal but once it
+    becomes, you will be glad to have a cache system in place.
+
+    How Caching Works
+    =================
+
+    Caching is pretty simple.  Basically you have a cache object lurking around
+    somewhere that is connected to a remote cache or the file system or
+    something else.  When the request comes in you check if the current page
+    is already in the cache and if so, you're returning it from the cache.
+    Otherwise you generate the page and put it into the cache. (Or a fragment
+    of the page, you don't have to cache the full thing)
+
+    Here is a simple example of how to cache a sidebar for 5 minutes::
+
+        def get_sidebar(user):
+            identifier = 'sidebar_for/user%d' % user.id
+            value = cache.get(identifier)
+            if value is not None:
+                return value
+            value = generate_sidebar_for(user=user)
+            cache.set(identifier, value, timeout=60 * 5)
+            return value
+
+    Creating a Cache Object
+    =======================
+
+    To create a cache object you just import the cache system of your choice
+    from the cache module and instantiate it.  Then you can start working
+    with that object:
+
+    >>> from werkzeug.contrib.cache import SimpleCache
+    >>> c = SimpleCache()
+    >>> c.set("foo", "value")
+    >>> c.get("foo")
+    'value'
+    >>> c.get("missing") is None
+    True
+
+    Please keep in mind that you have to create the cache and put it somewhere
+    you have access to it (either as a module global you can import or you just
+    put it into your WSGI application).
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import errno
+import os
+import platform
+import re
+import tempfile
+import warnings
+from hashlib import md5
+from time import time
+
+from .._compat import integer_types
+from .._compat import iteritems
+from .._compat import string_types
+from .._compat import text_type
+from .._compat import to_native
+from ..posixemulation import rename
+
+try:
+    import cPickle as pickle
+except ImportError:  # pragma: no cover
+    import pickle
+
+warnings.warn(
+    "'werkzeug.contrib.cache' is deprecated as of version 0.15 and will"
+    " be removed in version 1.0. It has moved to https://github.com"
+    "/pallets/cachelib.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+
+def _items(mappingorseq):
+    """Wrapper for efficient iteration over mappings represented by dicts
+    or sequences::
+
+        >>> for k, v in _items((i, i*i) for i in xrange(5)):
+        ...    assert k*k == v
+
+        >>> for k, v in _items(dict((i, i*i) for i in xrange(5))):
+        ...    assert k*k == v
+
+    """
+    if hasattr(mappingorseq, "items"):
+        return iteritems(mappingorseq)
+    return mappingorseq
+
+
+class BaseCache(object):
+    """Baseclass for the cache systems.  All the cache systems implement this
+    API or a superset of it.
+
+    :param default_timeout: the default timeout (in seconds) that is used if
+                            no timeout is specified on :meth:`set`. A timeout
+                            of 0 indicates that the cache never expires.
+    """
+
+    def __init__(self, default_timeout=300):
+        self.default_timeout = default_timeout
+
+    def _normalize_timeout(self, timeout):
+        if timeout is None:
+            timeout = self.default_timeout
+        return timeout
+
+    def get(self, key):
+        """Look up key in the cache and return the value for it.
+
+        :param key: the key to be looked up.
+        :returns: The value if it exists and is readable, else ``None``.
+        """
+        return None
+
+    def delete(self, key):
+        """Delete `key` from the cache.
+
+        :param key: the key to delete.
+        :returns: Whether the key existed and has been deleted.
+        :rtype: boolean
+        """
+        return True
+
+    def get_many(self, *keys):
+        """Returns a list of values for the given keys.
+        For each key an item in the list is created::
+
+            foo, bar = cache.get_many("foo", "bar")
+
+        Has the same error handling as :meth:`get`.
+
+        :param keys: The function accepts multiple keys as positional
+                     arguments.
+        """
+        return [self.get(k) for k in keys]
+
+    def get_dict(self, *keys):
+        """Like :meth:`get_many` but return a dict::
+
+            d = cache.get_dict("foo", "bar")
+            foo = d["foo"]
+            bar = d["bar"]
+
+        :param keys: The function accepts multiple keys as positional
+                     arguments.
+        """
+        return dict(zip(keys, self.get_many(*keys)))
+
+    def set(self, key, value, timeout=None):
+        """Add a new key/value to the cache (overwrites value, if key already
+        exists in the cache).
+
+        :param key: the key to set
+        :param value: the value for the key
+        :param timeout: the cache timeout for the key in seconds (if not
+                        specified, it uses the default timeout). A timeout of
+                        0 idicates that the cache never expires.
+        :returns: ``True`` if key has been updated, ``False`` for backend
+                  errors. Pickling errors, however, will raise a subclass of
+                  ``pickle.PickleError``.
+        :rtype: boolean
+        """
+        return True
+
+    def add(self, key, value, timeout=None):
+        """Works like :meth:`set` but does not overwrite the values of already
+        existing keys.
+
+        :param key: the key to set
+        :param value: the value for the key
+        :param timeout: the cache timeout for the key in seconds (if not
+                        specified, it uses the default timeout). A timeout of
+                        0 idicates that the cache never expires.
+        :returns: Same as :meth:`set`, but also ``False`` for already
+                  existing keys.
+        :rtype: boolean
+        """
+        return True
+
+    def set_many(self, mapping, timeout=None):
+        """Sets multiple keys and values from a mapping.
+
+        :param mapping: a mapping with the keys/values to set.
+        :param timeout: the cache timeout for the key in seconds (if not
+                        specified, it uses the default timeout). A timeout of
+                        0 idicates that the cache never expires.
+        :returns: Whether all given keys have been set.
+        :rtype: boolean
+        """
+        rv = True
+        for key, value in _items(mapping):
+            if not self.set(key, value, timeout):
+                rv = False
+        return rv
+
+    def delete_many(self, *keys):
+        """Deletes multiple keys at once.
+
+        :param keys: The function accepts multiple keys as positional
+                     arguments.
+        :returns: Whether all given keys have been deleted.
+        :rtype: boolean
+        """
+        return all(self.delete(key) for key in keys)
+
+    def has(self, key):
+        """Checks if a key exists in the cache without returning it. This is a
+        cheap operation that bypasses loading the actual data on the backend.
+
+        This method is optional and may not be implemented on all caches.
+
+        :param key: the key to check
+        """
+        raise NotImplementedError(
+            "%s doesn't have an efficient implementation of `has`. That "
+            "means it is impossible to check whether a key exists without "
+            "fully loading the key's data. Consider using `self.get` "
+            "explicitly if you don't care about performance."
+        )
+
+    def clear(self):
+        """Clears the cache.  Keep in mind that not all caches support
+        completely clearing the cache.
+
+        :returns: Whether the cache has been cleared.
+        :rtype: boolean
+        """
+        return True
+
+    def inc(self, key, delta=1):
+        """Increments the value of a key by `delta`.  If the key does
+        not yet exist it is initialized with `delta`.
+
+        For supporting caches this is an atomic operation.
+
+        :param key: the key to increment.
+        :param delta: the delta to add.
+        :returns: The new value or ``None`` for backend errors.
+        """
+        value = (self.get(key) or 0) + delta
+        return value if self.set(key, value) else None
+
+    def dec(self, key, delta=1):
+        """Decrements the value of a key by `delta`.  If the key does
+        not yet exist it is initialized with `-delta`.
+
+        For supporting caches this is an atomic operation.
+
+        :param key: the key to increment.
+        :param delta: the delta to subtract.
+        :returns: The new value or `None` for backend errors.
+        """
+        value = (self.get(key) or 0) - delta
+        return value if self.set(key, value) else None
+
+
+class NullCache(BaseCache):
+    """A cache that doesn't cache.  This can be useful for unit testing.
+
+    :param default_timeout: a dummy parameter that is ignored but exists
+                            for API compatibility with other caches.
+    """
+
+    def has(self, key):
+        return False
+
+
+class SimpleCache(BaseCache):
+    """Simple memory cache for single process environments.  This class exists
+    mainly for the development server and is not 100% thread safe.  It tries
+    to use as many atomic operations as possible and no locks for simplicity
+    but it could happen under heavy load that keys are added multiple times.
+
+    :param threshold: the maximum number of items the cache stores before
+                      it starts deleting some.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    """
+
+    def __init__(self, threshold=500, default_timeout=300):
+        BaseCache.__init__(self, default_timeout)
+        self._cache = {}
+        self.clear = self._cache.clear
+        self._threshold = threshold
+
+    def _prune(self):
+        if len(self._cache) > self._threshold:
+            now = time()
+            toremove = []
+            for idx, (key, (expires, _)) in enumerate(self._cache.items()):
+                if (expires != 0 and expires <= now) or idx % 3 == 0:
+                    toremove.append(key)
+            for key in toremove:
+                self._cache.pop(key, None)
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout > 0:
+            timeout = time() + timeout
+        return timeout
+
+    def get(self, key):
+        try:
+            expires, value = self._cache[key]
+            if expires == 0 or expires > time():
+                return pickle.loads(value)
+        except (KeyError, pickle.PickleError):
+            return None
+
+    def set(self, key, value, timeout=None):
+        expires = self._normalize_timeout(timeout)
+        self._prune()
+        self._cache[key] = (expires, pickle.dumps(value, pickle.HIGHEST_PROTOCOL))
+        return True
+
+    def add(self, key, value, timeout=None):
+        expires = self._normalize_timeout(timeout)
+        self._prune()
+        item = (expires, pickle.dumps(value, pickle.HIGHEST_PROTOCOL))
+        if key in self._cache:
+            return False
+        self._cache.setdefault(key, item)
+        return True
+
+    def delete(self, key):
+        return self._cache.pop(key, None) is not None
+
+    def has(self, key):
+        try:
+            expires, value = self._cache[key]
+            return expires == 0 or expires > time()
+        except KeyError:
+            return False
+
+
+_test_memcached_key = re.compile(r"[^\x00-\x21\xff]{1,250}$").match
+
+
+class MemcachedCache(BaseCache):
+    """A cache that uses memcached as backend.
+
+    The first argument can either be an object that resembles the API of a
+    :class:`memcache.Client` or a tuple/list of server addresses. In the
+    event that a tuple/list is passed, Werkzeug tries to import the best
+    available memcache library.
+
+    This cache looks into the following packages/modules to find bindings for
+    memcached:
+
+        - ``pylibmc``
+        - ``google.appengine.api.memcached``
+        - ``memcached``
+        - ``libmc``
+
+    Implementation notes:  This cache backend works around some limitations in
+    memcached to simplify the interface.  For example unicode keys are encoded
+    to utf-8 on the fly.  Methods such as :meth:`~BaseCache.get_dict` return
+    the keys in the same format as passed.  Furthermore all get methods
+    silently ignore key errors to not cause problems when untrusted user data
+    is passed to the get methods which is often the case in web applications.
+
+    :param servers: a list or tuple of server addresses or alternatively
+                    a :class:`memcache.Client` or a compatible client.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    :param key_prefix: a prefix that is added before all keys.  This makes it
+                       possible to use the same memcached server for different
+                       applications.  Keep in mind that
+                       :meth:`~BaseCache.clear` will also clear keys with a
+                       different prefix.
+    """
+
+    def __init__(self, servers=None, default_timeout=300, key_prefix=None):
+        BaseCache.__init__(self, default_timeout)
+        if servers is None or isinstance(servers, (list, tuple)):
+            if servers is None:
+                servers = ["127.0.0.1:11211"]
+            self._client = self.import_preferred_memcache_lib(servers)
+            if self._client is None:
+                raise RuntimeError("no memcache module found")
+        else:
+            # NOTE: servers is actually an already initialized memcache
+            # client.
+            self._client = servers
+
+        self.key_prefix = to_native(key_prefix)
+
+    def _normalize_key(self, key):
+        key = to_native(key, "utf-8")
+        if self.key_prefix:
+            key = self.key_prefix + key
+        return key
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout > 0:
+            timeout = int(time()) + timeout
+        return timeout
+
+    def get(self, key):
+        key = self._normalize_key(key)
+        # memcached doesn't support keys longer than that.  Because often
+        # checks for so long keys can occur because it's tested from user
+        # submitted data etc we fail silently for getting.
+        if _test_memcached_key(key):
+            return self._client.get(key)
+
+    def get_dict(self, *keys):
+        key_mapping = {}
+        have_encoded_keys = False
+        for key in keys:
+            encoded_key = self._normalize_key(key)
+            if not isinstance(key, str):
+                have_encoded_keys = True
+            if _test_memcached_key(key):
+                key_mapping[encoded_key] = key
+        _keys = list(key_mapping)
+        d = rv = self._client.get_multi(_keys)
+        if have_encoded_keys or self.key_prefix:
+            rv = {}
+            for key, value in iteritems(d):
+                rv[key_mapping[key]] = value
+        if len(rv) < len(keys):
+            for key in keys:
+                if key not in rv:
+                    rv[key] = None
+        return rv
+
+    def add(self, key, value, timeout=None):
+        key = self._normalize_key(key)
+        timeout = self._normalize_timeout(timeout)
+        return self._client.add(key, value, timeout)
+
+    def set(self, key, value, timeout=None):
+        key = self._normalize_key(key)
+        timeout = self._normalize_timeout(timeout)
+        return self._client.set(key, value, timeout)
+
+    def get_many(self, *keys):
+        d = self.get_dict(*keys)
+        return [d[key] for key in keys]
+
+    def set_many(self, mapping, timeout=None):
+        new_mapping = {}
+        for key, value in _items(mapping):
+            key = self._normalize_key(key)
+            new_mapping[key] = value
+
+        timeout = self._normalize_timeout(timeout)
+        failed_keys = self._client.set_multi(new_mapping, timeout)
+        return not failed_keys
+
+    def delete(self, key):
+        key = self._normalize_key(key)
+        if _test_memcached_key(key):
+            return self._client.delete(key)
+
+    def delete_many(self, *keys):
+        new_keys = []
+        for key in keys:
+            key = self._normalize_key(key)
+            if _test_memcached_key(key):
+                new_keys.append(key)
+        return self._client.delete_multi(new_keys)
+
+    def has(self, key):
+        key = self._normalize_key(key)
+        if _test_memcached_key(key):
+            return self._client.append(key, "")
+        return False
+
+    def clear(self):
+        return self._client.flush_all()
+
+    def inc(self, key, delta=1):
+        key = self._normalize_key(key)
+        return self._client.incr(key, delta)
+
+    def dec(self, key, delta=1):
+        key = self._normalize_key(key)
+        return self._client.decr(key, delta)
+
+    def import_preferred_memcache_lib(self, servers):
+        """Returns an initialized memcache client.  Used by the constructor."""
+        try:
+            import pylibmc
+        except ImportError:
+            pass
+        else:
+            return pylibmc.Client(servers)
+
+        try:
+            from google.appengine.api import memcache
+        except ImportError:
+            pass
+        else:
+            return memcache.Client()
+
+        try:
+            import memcache
+        except ImportError:
+            pass
+        else:
+            return memcache.Client(servers)
+
+        try:
+            import libmc
+        except ImportError:
+            pass
+        else:
+            return libmc.Client(servers)
+
+
+# backwards compatibility
+GAEMemcachedCache = MemcachedCache
+
+
+class RedisCache(BaseCache):
+    """Uses the Redis key-value store as a cache backend.
+
+    The first argument can be either a string denoting address of the Redis
+    server or an object resembling an instance of a redis.Redis class.
+
+    Note: Python Redis API already takes care of encoding unicode strings on
+    the fly.
+
+    .. versionadded:: 0.7
+
+    .. versionadded:: 0.8
+       `key_prefix` was added.
+
+    .. versionchanged:: 0.8
+       This cache backend now properly serializes objects.
+
+    .. versionchanged:: 0.8.3
+       This cache backend now supports password authentication.
+
+    .. versionchanged:: 0.10
+        ``**kwargs`` is now passed to the redis object.
+
+    :param host: address of the Redis server or an object which API is
+                 compatible with the official Python Redis client (redis-py).
+    :param port: port number on which Redis server listens for connections.
+    :param password: password authentication for the Redis server.
+    :param db: db (zero-based numeric index) on Redis Server to connect.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    :param key_prefix: A prefix that should be added to all keys.
+
+    Any additional keyword arguments will be passed to ``redis.Redis``.
+    """
+
+    def __init__(
+        self,
+        host="localhost",
+        port=6379,
+        password=None,
+        db=0,
+        default_timeout=300,
+        key_prefix=None,
+        **kwargs
+    ):
+        BaseCache.__init__(self, default_timeout)
+        if host is None:
+            raise ValueError("RedisCache host parameter may not be None")
+        if isinstance(host, string_types):
+            try:
+                import redis
+            except ImportError:
+                raise RuntimeError("no redis module found")
+            if kwargs.get("decode_responses", None):
+                raise ValueError("decode_responses is not supported by RedisCache.")
+            self._client = redis.Redis(
+                host=host, port=port, password=password, db=db, **kwargs
+            )
+        else:
+            self._client = host
+        self.key_prefix = key_prefix or ""
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout == 0:
+            timeout = -1
+        return timeout
+
+    def dump_object(self, value):
+        """Dumps an object into a string for redis.  By default it serializes
+        integers as regular string and pickle dumps everything else.
+        """
+        t = type(value)
+        if t in integer_types:
+            return str(value).encode("ascii")
+        return b"!" + pickle.dumps(value)
+
+    def load_object(self, value):
+        """The reversal of :meth:`dump_object`.  This might be called with
+        None.
+        """
+        if value is None:
+            return None
+        if value.startswith(b"!"):
+            try:
+                return pickle.loads(value[1:])
+            except pickle.PickleError:
+                return None
+        try:
+            return int(value)
+        except ValueError:
+            # before 0.8 we did not have serialization.  Still support that.
+            return value
+
+    def get(self, key):
+        return self.load_object(self._client.get(self.key_prefix + key))
+
+    def get_many(self, *keys):
+        if self.key_prefix:
+            keys = [self.key_prefix + key for key in keys]
+        return [self.load_object(x) for x in self._client.mget(keys)]
+
+    def set(self, key, value, timeout=None):
+        timeout = self._normalize_timeout(timeout)
+        dump = self.dump_object(value)
+        if timeout == -1:
+            result = self._client.set(name=self.key_prefix + key, value=dump)
+        else:
+            result = self._client.setex(
+                name=self.key_prefix + key, value=dump, time=timeout
+            )
+        return result
+
+    def add(self, key, value, timeout=None):
+        timeout = self._normalize_timeout(timeout)
+        dump = self.dump_object(value)
+        return self._client.setnx(
+            name=self.key_prefix + key, value=dump
+        ) and self._client.expire(name=self.key_prefix + key, time=timeout)
+
+    def set_many(self, mapping, timeout=None):
+        timeout = self._normalize_timeout(timeout)
+        # Use transaction=False to batch without calling redis MULTI
+        # which is not supported by twemproxy
+        pipe = self._client.pipeline(transaction=False)
+
+        for key, value in _items(mapping):
+            dump = self.dump_object(value)
+            if timeout == -1:
+                pipe.set(name=self.key_prefix + key, value=dump)
+            else:
+                pipe.setex(name=self.key_prefix + key, value=dump, time=timeout)
+        return pipe.execute()
+
+    def delete(self, key):
+        return self._client.delete(self.key_prefix + key)
+
+    def delete_many(self, *keys):
+        if not keys:
+            return
+        if self.key_prefix:
+            keys = [self.key_prefix + key for key in keys]
+        return self._client.delete(*keys)
+
+    def has(self, key):
+        return self._client.exists(self.key_prefix + key)
+
+    def clear(self):
+        status = False
+        if self.key_prefix:
+            keys = self._client.keys(self.key_prefix + "*")
+            if keys:
+                status = self._client.delete(*keys)
+        else:
+            status = self._client.flushdb()
+        return status
+
+    def inc(self, key, delta=1):
+        return self._client.incr(name=self.key_prefix + key, amount=delta)
+
+    def dec(self, key, delta=1):
+        return self._client.decr(name=self.key_prefix + key, amount=delta)
+
+
+class FileSystemCache(BaseCache):
+    """A cache that stores the items on the file system.  This cache depends
+    on being the only user of the `cache_dir`.  Make absolutely sure that
+    nobody but this cache stores files there or otherwise the cache will
+    randomly delete files therein.
+
+    :param cache_dir: the directory where cache files are stored.
+    :param threshold: the maximum number of items the cache stores before
+                      it starts deleting some. A threshold value of 0
+                      indicates no threshold.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    :param mode: the file mode wanted for the cache files, default 0600
+    """
+
+    #: used for temporary files by the FileSystemCache
+    _fs_transaction_suffix = ".__wz_cache"
+    #: keep amount of files in a cache element
+    _fs_count_file = "__wz_cache_count"
+
+    def __init__(self, cache_dir, threshold=500, default_timeout=300, mode=0o600):
+        BaseCache.__init__(self, default_timeout)
+        self._path = cache_dir
+        self._threshold = threshold
+        self._mode = mode
+
+        try:
+            os.makedirs(self._path)
+        except OSError as ex:
+            if ex.errno != errno.EEXIST:
+                raise
+
+        self._update_count(value=len(self._list_dir()))
+
+    @property
+    def _file_count(self):
+        return self.get(self._fs_count_file) or 0
+
+    def _update_count(self, delta=None, value=None):
+        # If we have no threshold, don't count files
+        if self._threshold == 0:
+            return
+
+        if delta:
+            new_count = self._file_count + delta
+        else:
+            new_count = value or 0
+        self.set(self._fs_count_file, new_count, mgmt_element=True)
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout != 0:
+            timeout = time() + timeout
+        return int(timeout)
+
+    def _list_dir(self):
+        """return a list of (fully qualified) cache filenames
+        """
+        mgmt_files = [
+            self._get_filename(name).split("/")[-1] for name in (self._fs_count_file,)
+        ]
+        return [
+            os.path.join(self._path, fn)
+            for fn in os.listdir(self._path)
+            if not fn.endswith(self._fs_transaction_suffix) and fn not in mgmt_files
+        ]
+
+    def _prune(self):
+        if self._threshold == 0 or not self._file_count > self._threshold:
+            return
+
+        entries = self._list_dir()
+        now = time()
+        for idx, fname in enumerate(entries):
+            try:
+                remove = False
+                with open(fname, "rb") as f:
+                    expires = pickle.load(f)
+                remove = (expires != 0 and expires <= now) or idx % 3 == 0
+
+                if remove:
+                    os.remove(fname)
+            except (IOError, OSError):
+                pass
+        self._update_count(value=len(self._list_dir()))
+
+    def clear(self):
+        for fname in self._list_dir():
+            try:
+                os.remove(fname)
+            except (IOError, OSError):
+                self._update_count(value=len(self._list_dir()))
+                return False
+        self._update_count(value=0)
+        return True
+
+    def _get_filename(self, key):
+        if isinstance(key, text_type):
+            key = key.encode("utf-8")  # XXX unicode review
+        hash = md5(key).hexdigest()
+        return os.path.join(self._path, hash)
+
+    def get(self, key):
+        filename = self._get_filename(key)
+        try:
+            with open(filename, "rb") as f:
+                pickle_time = pickle.load(f)
+                if pickle_time == 0 or pickle_time >= time():
+                    return pickle.load(f)
+                else:
+                    os.remove(filename)
+                    return None
+        except (IOError, OSError, pickle.PickleError):
+            return None
+
+    def add(self, key, value, timeout=None):
+        filename = self._get_filename(key)
+        if not os.path.exists(filename):
+            return self.set(key, value, timeout)
+        return False
+
+    def set(self, key, value, timeout=None, mgmt_element=False):
+        # Management elements have no timeout
+        if mgmt_element:
+            timeout = 0
+
+        # Don't prune on management element update, to avoid loop
+        else:
+            self._prune()
+
+        timeout = self._normalize_timeout(timeout)
+        filename = self._get_filename(key)
+        try:
+            fd, tmp = tempfile.mkstemp(
+                suffix=self._fs_transaction_suffix, dir=self._path
+            )
+            with os.fdopen(fd, "wb") as f:
+                pickle.dump(timeout, f, 1)
+                pickle.dump(value, f, pickle.HIGHEST_PROTOCOL)
+            rename(tmp, filename)
+            os.chmod(filename, self._mode)
+        except (IOError, OSError):
+            return False
+        else:
+            # Management elements should not count towards threshold
+            if not mgmt_element:
+                self._update_count(delta=1)
+            return True
+
+    def delete(self, key, mgmt_element=False):
+        try:
+            os.remove(self._get_filename(key))
+        except (IOError, OSError):
+            return False
+        else:
+            # Management elements should not count towards threshold
+            if not mgmt_element:
+                self._update_count(delta=-1)
+            return True
+
+    def has(self, key):
+        filename = self._get_filename(key)
+        try:
+            with open(filename, "rb") as f:
+                pickle_time = pickle.load(f)
+                if pickle_time == 0 or pickle_time >= time():
+                    return True
+                else:
+                    os.remove(filename)
+                    return False
+        except (IOError, OSError, pickle.PickleError):
+            return False
+
+
+class UWSGICache(BaseCache):
+    """Implements the cache using uWSGI's caching framework.
+
+    .. note::
+        This class cannot be used when running under PyPy, because the uWSGI
+        API implementation for PyPy is lacking the needed functionality.
+
+    :param default_timeout: The default timeout in seconds.
+    :param cache: The name of the caching instance to connect to, for
+        example: mycache@localhost:3031, defaults to an empty string, which
+        means uWSGI will cache in the local instance. If the cache is in the
+        same instance as the werkzeug app, you only have to provide the name of
+        the cache.
+    """
+
+    def __init__(self, default_timeout=300, cache=""):
+        BaseCache.__init__(self, default_timeout)
+
+        if platform.python_implementation() == "PyPy":
+            raise RuntimeError(
+                "uWSGI caching does not work under PyPy, see "
+                "the docs for more details."
+            )
+
+        try:
+            import uwsgi
+
+            self._uwsgi = uwsgi
+        except ImportError:
+            raise RuntimeError(
+                "uWSGI could not be imported, are you running under uWSGI?"
+            )
+
+        self.cache = cache
+
+    def get(self, key):
+        rv = self._uwsgi.cache_get(key, self.cache)
+        if rv is None:
+            return
+        return pickle.loads(rv)
+
+    def delete(self, key):
+        return self._uwsgi.cache_del(key, self.cache)
+
+    def set(self, key, value, timeout=None):
+        return self._uwsgi.cache_update(
+            key, pickle.dumps(value), self._normalize_timeout(timeout), self.cache
+        )
+
+    def add(self, key, value, timeout=None):
+        return self._uwsgi.cache_set(
+            key, pickle.dumps(value), self._normalize_timeout(timeout), self.cache
+        )
+
+    def clear(self):
+        return self._uwsgi.cache_clear(self.cache)
+
+    def has(self, key):
+        return self._uwsgi.cache_exists(key, self.cache) is not None
diff --git a/python/werkzeug/contrib/fixers.py b/python/werkzeug/contrib/fixers.py
new file mode 100644
index 0000000..8df0afd
--- /dev/null
+++ b/python/werkzeug/contrib/fixers.py
@@ -0,0 +1,262 @@
+"""
+Fixers
+======
+
+.. warning::
+    .. deprecated:: 0.15
+        ``ProxyFix`` has moved to :mod:`werkzeug.middleware.proxy_fix`.
+        All other code in this module is deprecated and will be removed
+        in version 1.0.
+
+.. versionadded:: 0.5
+
+This module includes various helpers that fix web server behavior.
+
+.. autoclass:: ProxyFix
+   :members:
+
+.. autoclass:: CGIRootFix
+
+.. autoclass:: PathInfoFromRequestUriFix
+
+.. autoclass:: HeaderRewriterFix
+
+.. autoclass:: InternetExplorerFix
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+import warnings
+
+from ..datastructures import Headers
+from ..datastructures import ResponseCacheControl
+from ..http import parse_cache_control_header
+from ..http import parse_options_header
+from ..http import parse_set_header
+from ..middleware.proxy_fix import ProxyFix as _ProxyFix
+from ..useragents import UserAgent
+
+try:
+    from urllib.parse import unquote
+except ImportError:
+    from urllib import unquote
+
+
+class CGIRootFix(object):
+    """Wrap the application in this middleware if you are using FastCGI
+    or CGI and you have problems with your app root being set to the CGI
+    script's path instead of the path users are going to visit.
+
+    :param app: the WSGI application
+    :param app_root: Defaulting to ``'/'``, you can set this to
+        something else if your app is mounted somewhere else.
+
+    .. deprecated:: 0.15
+        This middleware will be removed in version 1.0.
+
+    .. versionchanged:: 0.9
+        Added `app_root` parameter and renamed from
+        ``LighttpdCGIRootFix``.
+    """
+
+    def __init__(self, app, app_root="/"):
+        warnings.warn(
+            "'CGIRootFix' is deprecated as of version 0.15 and will be"
+            " removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        self.app = app
+        self.app_root = app_root.strip("/")
+
+    def __call__(self, environ, start_response):
+        environ["SCRIPT_NAME"] = self.app_root
+        return self.app(environ, start_response)
+
+
+class LighttpdCGIRootFix(CGIRootFix):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'LighttpdCGIRootFix' is renamed 'CGIRootFix'. Both will be"
+            " removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(LighttpdCGIRootFix, self).__init__(*args, **kwargs)
+
+
+class PathInfoFromRequestUriFix(object):
+    """On windows environment variables are limited to the system charset
+    which makes it impossible to store the `PATH_INFO` variable in the
+    environment without loss of information on some systems.
+
+    This is for example a problem for CGI scripts on a Windows Apache.
+
+    This fixer works by recreating the `PATH_INFO` from `REQUEST_URI`,
+    `REQUEST_URL`, or `UNENCODED_URL` (whatever is available).  Thus the
+    fix can only be applied if the webserver supports either of these
+    variables.
+
+    :param app: the WSGI application
+
+    .. deprecated:: 0.15
+        This middleware will be removed in version 1.0.
+    """
+
+    def __init__(self, app):
+        warnings.warn(
+            "'PathInfoFromRequestUriFix' is deprecated as of version"
+            " 0.15 and will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        self.app = app
+
+    def __call__(self, environ, start_response):
+        for key in "REQUEST_URL", "REQUEST_URI", "UNENCODED_URL":
+            if key not in environ:
+                continue
+            request_uri = unquote(environ[key])
+            script_name = unquote(environ.get("SCRIPT_NAME", ""))
+            if request_uri.startswith(script_name):
+                environ["PATH_INFO"] = request_uri[len(script_name) :].split("?", 1)[0]
+                break
+        return self.app(environ, start_response)
+
+
+class ProxyFix(_ProxyFix):
+    """
+    .. deprecated:: 0.15
+        ``werkzeug.contrib.fixers.ProxyFix`` has moved to
+        :mod:`werkzeug.middleware.proxy_fix`. This import will be
+        removed in 1.0.
+    """
+
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.contrib.fixers.ProxyFix' has moved to 'werkzeug"
+            ".middleware.proxy_fix.ProxyFix'. This import is deprecated"
+            " as of version 0.15 and will be removed in 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(ProxyFix, self).__init__(*args, **kwargs)
+
+
+class HeaderRewriterFix(object):
+    """This middleware can remove response headers and add others.  This
+    is for example useful to remove the `Date` header from responses if you
+    are using a server that adds that header, no matter if it's present or
+    not or to add `X-Powered-By` headers::
+
+        app = HeaderRewriterFix(app, remove_headers=['Date'],
+                                add_headers=[('X-Powered-By', 'WSGI')])
+
+    :param app: the WSGI application
+    :param remove_headers: a sequence of header keys that should be
+                           removed.
+    :param add_headers: a sequence of ``(key, value)`` tuples that should
+                        be added.
+
+    .. deprecated:: 0.15
+        This middleware will be removed in 1.0.
+    """
+
+    def __init__(self, app, remove_headers=None, add_headers=None):
+        warnings.warn(
+            "'HeaderRewriterFix' is deprecated as of version 0.15 and"
+            " will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        self.app = app
+        self.remove_headers = set(x.lower() for x in (remove_headers or ()))
+        self.add_headers = list(add_headers or ())
+
+    def __call__(self, environ, start_response):
+        def rewriting_start_response(status, headers, exc_info=None):
+            new_headers = []
+            for key, value in headers:
+                if key.lower() not in self.remove_headers:
+                    new_headers.append((key, value))
+            new_headers += self.add_headers
+            return start_response(status, new_headers, exc_info)
+
+        return self.app(environ, rewriting_start_response)
+
+
+class InternetExplorerFix(object):
+    """This middleware fixes a couple of bugs with Microsoft Internet
+    Explorer.  Currently the following fixes are applied:
+
+    -   removing of `Vary` headers for unsupported mimetypes which
+        causes troubles with caching.  Can be disabled by passing
+        ``fix_vary=False`` to the constructor.
+        see: https://support.microsoft.com/en-us/help/824847
+
+    -   removes offending headers to work around caching bugs in
+        Internet Explorer if `Content-Disposition` is set.  Can be
+        disabled by passing ``fix_attach=False`` to the constructor.
+
+    If it does not detect affected Internet Explorer versions it won't touch
+    the request / response.
+
+    .. deprecated:: 0.15
+        This middleware will be removed in 1.0.
+    """
+
+    # This code was inspired by Django fixers for the same bugs.  The
+    # fix_vary and fix_attach fixers were originally implemented in Django
+    # by Michael Axiak and is available as part of the Django project:
+    #     https://code.djangoproject.com/ticket/4148
+
+    def __init__(self, app, fix_vary=True, fix_attach=True):
+        warnings.warn(
+            "'InternetExplorerFix' is deprecated as of version 0.15 and"
+            " will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        self.app = app
+        self.fix_vary = fix_vary
+        self.fix_attach = fix_attach
+
+    def fix_headers(self, environ, headers, status=None):
+        if self.fix_vary:
+            header = headers.get("content-type", "")
+            mimetype, options = parse_options_header(header)
+            if mimetype not in ("text/html", "text/plain", "text/sgml"):
+                headers.pop("vary", None)
+
+        if self.fix_attach and "content-disposition" in headers:
+            pragma = parse_set_header(headers.get("pragma", ""))
+            pragma.discard("no-cache")
+            header = pragma.to_header()
+            if not header:
+                headers.pop("pragma", "")
+            else:
+                headers["Pragma"] = header
+            header = headers.get("cache-control", "")
+            if header:
+                cc = parse_cache_control_header(header, cls=ResponseCacheControl)
+                cc.no_cache = None
+                cc.no_store = False
+                header = cc.to_header()
+                if not header:
+                    headers.pop("cache-control", "")
+                else:
+                    headers["Cache-Control"] = header
+
+    def run_fixed(self, environ, start_response):
+        def fixing_start_response(status, headers, exc_info=None):
+            headers = Headers(headers)
+            self.fix_headers(environ, headers, status)
+            return start_response(status, headers.to_wsgi_list(), exc_info)
+
+        return self.app(environ, fixing_start_response)
+
+    def __call__(self, environ, start_response):
+        ua = UserAgent(environ)
+        if ua.browser != "msie":
+            return self.app(environ, start_response)
+        return self.run_fixed(environ, start_response)
diff --git a/python/werkzeug/contrib/iterio.py b/python/werkzeug/contrib/iterio.py
new file mode 100644
index 0000000..b672454
--- /dev/null
+++ b/python/werkzeug/contrib/iterio.py
@@ -0,0 +1,358 @@
+# -*- coding: utf-8 -*-
+r"""
+    werkzeug.contrib.iterio
+    ~~~~~~~~~~~~~~~~~~~~~~~
+
+    This module implements a :class:`IterIO` that converts an iterator into
+    a stream object and the other way round.  Converting streams into
+    iterators requires the `greenlet`_ module.
+
+    To convert an iterator into a stream all you have to do is to pass it
+    directly to the :class:`IterIO` constructor.  In this example we pass it
+    a newly created generator::
+
+        def foo():
+            yield "something\n"
+            yield "otherthings"
+        stream = IterIO(foo())
+        print stream.read()         # read the whole iterator
+
+    The other way round works a bit different because we have to ensure that
+    the code execution doesn't take place yet.  An :class:`IterIO` call with a
+    callable as first argument does two things.  The function itself is passed
+    an :class:`IterIO` stream it can feed.  The object returned by the
+    :class:`IterIO` constructor on the other hand is not an stream object but
+    an iterator::
+
+        def foo(stream):
+            stream.write("some")
+            stream.write("thing")
+            stream.flush()
+            stream.write("otherthing")
+        iterator = IterIO(foo)
+        print iterator.next()       # prints something
+        print iterator.next()       # prints otherthing
+        iterator.next()             # raises StopIteration
+
+    .. _greenlet: https://github.com/python-greenlet/greenlet
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import warnings
+
+from .._compat import implements_iterator
+
+try:
+    import greenlet
+except ImportError:
+    greenlet = None
+
+warnings.warn(
+    "'werkzeug.contrib.iterio' is deprecated as of version 0.15 and"
+    " will be removed in version 1.0.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+
+def _mixed_join(iterable, sentinel):
+    """concatenate any string type in an intelligent way."""
+    iterator = iter(iterable)
+    first_item = next(iterator, sentinel)
+    if isinstance(first_item, bytes):
+        return first_item + b"".join(iterator)
+    return first_item + u"".join(iterator)
+
+
+def _newline(reference_string):
+    if isinstance(reference_string, bytes):
+        return b"\n"
+    return u"\n"
+
+
+@implements_iterator
+class IterIO(object):
+    """Instances of this object implement an interface compatible with the
+    standard Python :class:`file` object.  Streams are either read-only or
+    write-only depending on how the object is created.
+
+    If the first argument is an iterable a file like object is returned that
+    returns the contents of the iterable.  In case the iterable is empty
+    read operations will return the sentinel value.
+
+    If the first argument is a callable then the stream object will be
+    created and passed to that function.  The caller itself however will
+    not receive a stream but an iterable.  The function will be executed
+    step by step as something iterates over the returned iterable.  Each
+    call to :meth:`flush` will create an item for the iterable.  If
+    :meth:`flush` is called without any writes in-between the sentinel
+    value will be yielded.
+
+    Note for Python 3: due to the incompatible interface of bytes and
+    streams you should set the sentinel value explicitly to an empty
+    bytestring (``b''``) if you are expecting to deal with bytes as
+    otherwise the end of the stream is marked with the wrong sentinel
+    value.
+
+    .. versionadded:: 0.9
+       `sentinel` parameter was added.
+    """
+
+    def __new__(cls, obj, sentinel=""):
+        try:
+            iterator = iter(obj)
+        except TypeError:
+            return IterI(obj, sentinel)
+        return IterO(iterator, sentinel)
+
+    def __iter__(self):
+        return self
+
+    def tell(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        return self.pos
+
+    def isatty(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        return False
+
+    def seek(self, pos, mode=0):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def truncate(self, size=None):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def write(self, s):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def writelines(self, list):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def read(self, n=-1):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def readlines(self, sizehint=0):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def readline(self, length=None):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def flush(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        raise IOError(9, "Bad file descriptor")
+
+    def __next__(self):
+        if self.closed:
+            raise StopIteration()
+        line = self.readline()
+        if not line:
+            raise StopIteration()
+        return line
+
+
+class IterI(IterIO):
+    """Convert an stream into an iterator."""
+
+    def __new__(cls, func, sentinel=""):
+        if greenlet is None:
+            raise RuntimeError("IterI requires greenlet support")
+        stream = object.__new__(cls)
+        stream._parent = greenlet.getcurrent()
+        stream._buffer = []
+        stream.closed = False
+        stream.sentinel = sentinel
+        stream.pos = 0
+
+        def run():
+            func(stream)
+            stream.close()
+
+        g = greenlet.greenlet(run, stream._parent)
+        while 1:
+            rv = g.switch()
+            if not rv:
+                return
+            yield rv[0]
+
+    def close(self):
+        if not self.closed:
+            self.closed = True
+            self._flush_impl()
+
+    def write(self, s):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        if s:
+            self.pos += len(s)
+            self._buffer.append(s)
+
+    def writelines(self, list):
+        for item in list:
+            self.write(item)
+
+    def flush(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        self._flush_impl()
+
+    def _flush_impl(self):
+        data = _mixed_join(self._buffer, self.sentinel)
+        self._buffer = []
+        if not data and self.closed:
+            self._parent.switch()
+        else:
+            self._parent.switch((data,))
+
+
+class IterO(IterIO):
+    """Iter output.  Wrap an iterator and give it a stream like interface."""
+
+    def __new__(cls, gen, sentinel=""):
+        self = object.__new__(cls)
+        self._gen = gen
+        self._buf = None
+        self.sentinel = sentinel
+        self.closed = False
+        self.pos = 0
+        return self
+
+    def __iter__(self):
+        return self
+
+    def _buf_append(self, string):
+        """Replace string directly without appending to an empty string,
+        avoiding type issues."""
+        if not self._buf:
+            self._buf = string
+        else:
+            self._buf += string
+
+    def close(self):
+        if not self.closed:
+            self.closed = True
+            if hasattr(self._gen, "close"):
+                self._gen.close()
+
+    def seek(self, pos, mode=0):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        if mode == 1:
+            pos += self.pos
+        elif mode == 2:
+            self.read()
+            self.pos = min(self.pos, self.pos + pos)
+            return
+        elif mode != 0:
+            raise IOError("Invalid argument")
+        buf = []
+        try:
+            tmp_end_pos = len(self._buf or "")
+            while pos > tmp_end_pos:
+                item = next(self._gen)
+                tmp_end_pos += len(item)
+                buf.append(item)
+        except StopIteration:
+            pass
+        if buf:
+            self._buf_append(_mixed_join(buf, self.sentinel))
+        self.pos = max(0, pos)
+
+    def read(self, n=-1):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        if n < 0:
+            self._buf_append(_mixed_join(self._gen, self.sentinel))
+            result = self._buf[self.pos :]
+            self.pos += len(result)
+            return result
+        new_pos = self.pos + n
+        buf = []
+        try:
+            tmp_end_pos = 0 if self._buf is None else len(self._buf)
+            while new_pos > tmp_end_pos or (self._buf is None and not buf):
+                item = next(self._gen)
+                tmp_end_pos += len(item)
+                buf.append(item)
+        except StopIteration:
+            pass
+        if buf:
+            self._buf_append(_mixed_join(buf, self.sentinel))
+
+        if self._buf is None:
+            return self.sentinel
+
+        new_pos = max(0, new_pos)
+        try:
+            return self._buf[self.pos : new_pos]
+        finally:
+            self.pos = min(new_pos, len(self._buf))
+
+    def readline(self, length=None):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+
+        nl_pos = -1
+        if self._buf:
+            nl_pos = self._buf.find(_newline(self._buf), self.pos)
+        buf = []
+        try:
+            if self._buf is None:
+                pos = self.pos
+            else:
+                pos = len(self._buf)
+            while nl_pos < 0:
+                item = next(self._gen)
+                local_pos = item.find(_newline(item))
+                buf.append(item)
+                if local_pos >= 0:
+                    nl_pos = pos + local_pos
+                    break
+                pos += len(item)
+        except StopIteration:
+            pass
+        if buf:
+            self._buf_append(_mixed_join(buf, self.sentinel))
+
+        if self._buf is None:
+            return self.sentinel
+
+        if nl_pos < 0:
+            new_pos = len(self._buf)
+        else:
+            new_pos = nl_pos + 1
+        if length is not None and self.pos + length < new_pos:
+            new_pos = self.pos + length
+        try:
+            return self._buf[self.pos : new_pos]
+        finally:
+            self.pos = min(new_pos, len(self._buf))
+
+    def readlines(self, sizehint=0):
+        total = 0
+        lines = []
+        line = self.readline()
+        while line:
+            lines.append(line)
+            total += len(line)
+            if 0 < sizehint <= total:
+                break
+            line = self.readline()
+        return lines
diff --git a/python/werkzeug/contrib/lint.py b/python/werkzeug/contrib/lint.py
new file mode 100644
index 0000000..8bd8b8a
--- /dev/null
+++ b/python/werkzeug/contrib/lint.py
@@ -0,0 +1,11 @@
+import warnings
+
+from ..middleware.lint import *  # noqa: F401, F403
+
+warnings.warn(
+    "'werkzeug.contrib.lint' has moved to 'werkzeug.middleware.lint'."
+    " This import is deprecated as of version 0.15 and will be removed"
+    " in version 1.0.",
+    DeprecationWarning,
+    stacklevel=2,
+)
diff --git a/python/werkzeug/contrib/profiler.py b/python/werkzeug/contrib/profiler.py
new file mode 100644
index 0000000..b79fe56
--- /dev/null
+++ b/python/werkzeug/contrib/profiler.py
@@ -0,0 +1,42 @@
+import warnings
+
+from ..middleware.profiler import *  # noqa: F401, F403
+
+warnings.warn(
+    "'werkzeug.contrib.profiler' has moved to"
+    "'werkzeug.middleware.profiler'. This import is deprecated as of"
+    "version 0.15 and will be removed in version 1.0.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+
+class MergeStream(object):
+    """An object that redirects ``write`` calls to multiple streams.
+    Use this to log to both ``sys.stdout`` and a file::
+
+        f = open('profiler.log', 'w')
+        stream = MergeStream(sys.stdout, f)
+        profiler = ProfilerMiddleware(app, stream)
+
+    .. deprecated:: 0.15
+        Use the ``tee`` command in your terminal instead. This class
+        will be removed in 1.0.
+    """
+
+    def __init__(self, *streams):
+        warnings.warn(
+            "'MergeStream' is deprecated as of version 0.15 and will be removed in"
+            " version 1.0. Use your terminal's 'tee' command instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+
+        if not streams:
+            raise TypeError("At least one stream must be given.")
+
+        self.streams = streams
+
+    def write(self, data):
+        for stream in self.streams:
+            stream.write(data)
diff --git a/python/werkzeug/contrib/securecookie.py b/python/werkzeug/contrib/securecookie.py
new file mode 100644
index 0000000..c4c9eee
--- /dev/null
+++ b/python/werkzeug/contrib/securecookie.py
@@ -0,0 +1,362 @@
+# -*- coding: utf-8 -*-
+r"""
+    werkzeug.contrib.securecookie
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    This module implements a cookie that is not alterable from the client
+    because it adds a checksum the server checks for.  You can use it as
+    session replacement if all you have is a user id or something to mark
+    a logged in user.
+
+    Keep in mind that the data is still readable from the client as a
+    normal cookie is.  However you don't have to store and flush the
+    sessions you have at the server.
+
+    Example usage:
+
+    >>> from werkzeug.contrib.securecookie import SecureCookie
+    >>> x = SecureCookie({"foo": 42, "baz": (1, 2, 3)}, "deadbeef")
+
+    Dumping into a string so that one can store it in a cookie:
+
+    >>> value = x.serialize()
+
+    Loading from that string again:
+
+    >>> x = SecureCookie.unserialize(value, "deadbeef")
+    >>> x["baz"]
+    (1, 2, 3)
+
+    If someone modifies the cookie and the checksum is wrong the unserialize
+    method will fail silently and return a new empty `SecureCookie` object.
+
+    Keep in mind that the values will be visible in the cookie so do not
+    store data in a cookie you don't want the user to see.
+
+    Application Integration
+    =======================
+
+    If you are using the werkzeug request objects you could integrate the
+    secure cookie into your application like this::
+
+        from werkzeug.utils import cached_property
+        from werkzeug.wrappers import BaseRequest
+        from werkzeug.contrib.securecookie import SecureCookie
+
+        # don't use this key but a different one; you could just use
+        # os.urandom(20) to get something random
+        SECRET_KEY = '\xfa\xdd\xb8z\xae\xe0}4\x8b\xea'
+
+        class Request(BaseRequest):
+
+            @cached_property
+            def client_session(self):
+                data = self.cookies.get('session_data')
+                if not data:
+                    return SecureCookie(secret_key=SECRET_KEY)
+                return SecureCookie.unserialize(data, SECRET_KEY)
+
+        def application(environ, start_response):
+            request = Request(environ)
+
+            # get a response object here
+            response = ...
+
+            if request.client_session.should_save:
+                session_data = request.client_session.serialize()
+                response.set_cookie('session_data', session_data,
+                                    httponly=True)
+            return response(environ, start_response)
+
+    A less verbose integration can be achieved by using shorthand methods::
+
+        class Request(BaseRequest):
+
+            @cached_property
+            def client_session(self):
+                return SecureCookie.load_cookie(self, secret_key=COOKIE_SECRET)
+
+        def application(environ, start_response):
+            request = Request(environ)
+
+            # get a response object here
+            response = ...
+
+            request.client_session.save_cookie(response)
+            return response(environ, start_response)
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import base64
+import pickle
+import warnings
+from hashlib import sha1 as _default_hash
+from hmac import new as hmac
+from time import time
+
+from .._compat import iteritems
+from .._compat import text_type
+from .._compat import to_bytes
+from .._compat import to_native
+from .._internal import _date_to_unix
+from ..contrib.sessions import ModificationTrackingDict
+from ..security import safe_str_cmp
+from ..urls import url_quote_plus
+from ..urls import url_unquote_plus
+
+warnings.warn(
+    "'werkzeug.contrib.securecookie' is deprecated as of version 0.15"
+    " and will be removed in version 1.0. It has moved to"
+    " https://github.com/pallets/secure-cookie.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+
+class UnquoteError(Exception):
+    """Internal exception used to signal failures on quoting."""
+
+
+class SecureCookie(ModificationTrackingDict):
+    """Represents a secure cookie.  You can subclass this class and provide
+    an alternative mac method.  The import thing is that the mac method
+    is a function with a similar interface to the hashlib.  Required
+    methods are update() and digest().
+
+    Example usage:
+
+    >>> x = SecureCookie({"foo": 42, "baz": (1, 2, 3)}, "deadbeef")
+    >>> x["foo"]
+    42
+    >>> x["baz"]
+    (1, 2, 3)
+    >>> x["blafasel"] = 23
+    >>> x.should_save
+    True
+
+    :param data: the initial data.  Either a dict, list of tuples or `None`.
+    :param secret_key: the secret key.  If not set `None` or not specified
+                       it has to be set before :meth:`serialize` is called.
+    :param new: The initial value of the `new` flag.
+    """
+
+    #: The hash method to use.  This has to be a module with a new function
+    #: or a function that creates a hashlib object.  Such as `hashlib.md5`
+    #: Subclasses can override this attribute.  The default hash is sha1.
+    #: Make sure to wrap this in staticmethod() if you store an arbitrary
+    #: function there such as hashlib.sha1 which  might be implemented
+    #: as a function.
+    hash_method = staticmethod(_default_hash)
+
+    #: The module used for serialization. Should have a ``dumps`` and a
+    #: ``loads`` method that takes bytes. The default is :mod:`pickle`.
+    #:
+    #: .. versionchanged:: 0.15
+    #:     The default of ``pickle`` will change to :mod:`json` in 1.0.
+    serialization_method = pickle
+
+    #: if the contents should be base64 quoted.  This can be disabled if the
+    #: serialization process returns cookie safe strings only.
+    quote_base64 = True
+
+    def __init__(self, data=None, secret_key=None, new=True):
+        ModificationTrackingDict.__init__(self, data or ())
+        # explicitly convert it into a bytestring because python 2.6
+        # no longer performs an implicit string conversion on hmac
+        if secret_key is not None:
+            secret_key = to_bytes(secret_key, "utf-8")
+        self.secret_key = secret_key
+        self.new = new
+
+        if self.serialization_method is pickle:
+            warnings.warn(
+                "The default 'SecureCookie.serialization_method' will"
+                " change from pickle to json in version 1.0. To upgrade"
+                " existing tokens, override 'unquote' to try pickle if"
+                " json fails.",
+                stacklevel=2,
+            )
+
+    def __repr__(self):
+        return "<%s %s%s>" % (
+            self.__class__.__name__,
+            dict.__repr__(self),
+            "*" if self.should_save else "",
+        )
+
+    @property
+    def should_save(self):
+        """True if the session should be saved.  By default this is only true
+        for :attr:`modified` cookies, not :attr:`new`.
+        """
+        return self.modified
+
+    @classmethod
+    def quote(cls, value):
+        """Quote the value for the cookie.  This can be any object supported
+        by :attr:`serialization_method`.
+
+        :param value: the value to quote.
+        """
+        if cls.serialization_method is not None:
+            value = cls.serialization_method.dumps(value)
+        if cls.quote_base64:
+            value = b"".join(
+                base64.b64encode(to_bytes(value, "utf8")).splitlines()
+            ).strip()
+        return value
+
+    @classmethod
+    def unquote(cls, value):
+        """Unquote the value for the cookie.  If unquoting does not work a
+        :exc:`UnquoteError` is raised.
+
+        :param value: the value to unquote.
+        """
+        try:
+            if cls.quote_base64:
+                value = base64.b64decode(value)
+            if cls.serialization_method is not None:
+                value = cls.serialization_method.loads(value)
+            return value
+        except Exception:
+            # unfortunately pickle and other serialization modules can
+            # cause pretty every error here.  if we get one we catch it
+            # and convert it into an UnquoteError
+            raise UnquoteError()
+
+    def serialize(self, expires=None):
+        """Serialize the secure cookie into a string.
+
+        If expires is provided, the session will be automatically invalidated
+        after expiration when you unseralize it. This provides better
+        protection against session cookie theft.
+
+        :param expires: an optional expiration date for the cookie (a
+                        :class:`datetime.datetime` object)
+        """
+        if self.secret_key is None:
+            raise RuntimeError("no secret key defined")
+        if expires:
+            self["_expires"] = _date_to_unix(expires)
+        result = []
+        mac = hmac(self.secret_key, None, self.hash_method)
+        for key, value in sorted(self.items()):
+            result.append(
+                (
+                    "%s=%s" % (url_quote_plus(key), self.quote(value).decode("ascii"))
+                ).encode("ascii")
+            )
+            mac.update(b"|" + result[-1])
+        return b"?".join([base64.b64encode(mac.digest()).strip(), b"&".join(result)])
+
+    @classmethod
+    def unserialize(cls, string, secret_key):
+        """Load the secure cookie from a serialized string.
+
+        :param string: the cookie value to unserialize.
+        :param secret_key: the secret key used to serialize the cookie.
+        :return: a new :class:`SecureCookie`.
+        """
+        if isinstance(string, text_type):
+            string = string.encode("utf-8", "replace")
+        if isinstance(secret_key, text_type):
+            secret_key = secret_key.encode("utf-8", "replace")
+        try:
+            base64_hash, data = string.split(b"?", 1)
+        except (ValueError, IndexError):
+            items = ()
+        else:
+            items = {}
+            mac = hmac(secret_key, None, cls.hash_method)
+            for item in data.split(b"&"):
+                mac.update(b"|" + item)
+                if b"=" not in item:
+                    items = None
+                    break
+                key, value = item.split(b"=", 1)
+                # try to make the key a string
+                key = url_unquote_plus(key.decode("ascii"))
+                try:
+                    key = to_native(key)
+                except UnicodeError:
+                    pass
+                items[key] = value
+
+            # no parsing error and the mac looks okay, we can now
+            # sercurely unpickle our cookie.
+            try:
+                client_hash = base64.b64decode(base64_hash)
+            except TypeError:
+                items = client_hash = None
+            if items is not None and safe_str_cmp(client_hash, mac.digest()):
+                try:
+                    for key, value in iteritems(items):
+                        items[key] = cls.unquote(value)
+                except UnquoteError:
+                    items = ()
+                else:
+                    if "_expires" in items:
+                        if time() > items["_expires"]:
+                            items = ()
+                        else:
+                            del items["_expires"]
+            else:
+                items = ()
+        return cls(items, secret_key, False)
+
+    @classmethod
+    def load_cookie(cls, request, key="session", secret_key=None):
+        """Loads a :class:`SecureCookie` from a cookie in request.  If the
+        cookie is not set, a new :class:`SecureCookie` instanced is
+        returned.
+
+        :param request: a request object that has a `cookies` attribute
+                        which is a dict of all cookie values.
+        :param key: the name of the cookie.
+        :param secret_key: the secret key used to unquote the cookie.
+                           Always provide the value even though it has
+                           no default!
+        """
+        data = request.cookies.get(key)
+        if not data:
+            return cls(secret_key=secret_key)
+        return cls.unserialize(data, secret_key)
+
+    def save_cookie(
+        self,
+        response,
+        key="session",
+        expires=None,
+        session_expires=None,
+        max_age=None,
+        path="/",
+        domain=None,
+        secure=None,
+        httponly=False,
+        force=False,
+    ):
+        """Saves the SecureCookie in a cookie on response object.  All
+        parameters that are not described here are forwarded directly
+        to :meth:`~BaseResponse.set_cookie`.
+
+        :param response: a response object that has a
+                         :meth:`~BaseResponse.set_cookie` method.
+        :param key: the name of the cookie.
+        :param session_expires: the expiration date of the secure cookie
+                                stored information.  If this is not provided
+                                the cookie `expires` date is used instead.
+        """
+        if force or self.should_save:
+            data = self.serialize(session_expires or expires)
+            response.set_cookie(
+                key,
+                data,
+                expires=expires,
+                max_age=max_age,
+                path=path,
+                domain=domain,
+                secure=secure,
+                httponly=httponly,
+            )
diff --git a/python/werkzeug/contrib/sessions.py b/python/werkzeug/contrib/sessions.py
new file mode 100644
index 0000000..866e827
--- /dev/null
+++ b/python/werkzeug/contrib/sessions.py
@@ -0,0 +1,389 @@
+# -*- coding: utf-8 -*-
+r"""
+    werkzeug.contrib.sessions
+    ~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    This module contains some helper classes that help one to add session
+    support to a python WSGI application.  For full client-side session
+    storage see :mod:`~werkzeug.contrib.securecookie` which implements a
+    secure, client-side session storage.
+
+
+    Application Integration
+    =======================
+
+    ::
+
+        from werkzeug.contrib.sessions import SessionMiddleware, \
+             FilesystemSessionStore
+
+        app = SessionMiddleware(app, FilesystemSessionStore())
+
+    The current session will then appear in the WSGI environment as
+    `werkzeug.session`.  However it's recommended to not use the middleware
+    but the stores directly in the application.  However for very simple
+    scripts a middleware for sessions could be sufficient.
+
+    This module does not implement methods or ways to check if a session is
+    expired.  That should be done by a cronjob and storage specific.  For
+    example to prune unused filesystem sessions one could check the modified
+    time of the files.  If sessions are stored in the database the new()
+    method should add an expiration timestamp for the session.
+
+    For better flexibility it's recommended to not use the middleware but the
+    store and session object directly in the application dispatching::
+
+        session_store = FilesystemSessionStore()
+
+        def application(environ, start_response):
+            request = Request(environ)
+            sid = request.cookies.get('cookie_name')
+            if sid is None:
+                request.session = session_store.new()
+            else:
+                request.session = session_store.get(sid)
+            response = get_the_response_object(request)
+            if request.session.should_save:
+                session_store.save(request.session)
+                response.set_cookie('cookie_name', request.session.sid)
+            return response(environ, start_response)
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import os
+import re
+import tempfile
+import warnings
+from hashlib import sha1
+from os import path
+from pickle import dump
+from pickle import HIGHEST_PROTOCOL
+from pickle import load
+from random import random
+from time import time
+
+from .._compat import PY2
+from .._compat import text_type
+from ..datastructures import CallbackDict
+from ..filesystem import get_filesystem_encoding
+from ..posixemulation import rename
+from ..utils import dump_cookie
+from ..utils import parse_cookie
+from ..wsgi import ClosingIterator
+
+warnings.warn(
+    "'werkzeug.contrib.sessions' is deprecated as of version 0.15 and"
+    " will be removed in version 1.0. It has moved to"
+    " https://github.com/pallets/secure-cookie.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+_sha1_re = re.compile(r"^[a-f0-9]{40}$")
+
+
+def _urandom():
+    if hasattr(os, "urandom"):
+        return os.urandom(30)
+    return text_type(random()).encode("ascii")
+
+
+def generate_key(salt=None):
+    if salt is None:
+        salt = repr(salt).encode("ascii")
+    return sha1(b"".join([salt, str(time()).encode("ascii"), _urandom()])).hexdigest()
+
+
+class ModificationTrackingDict(CallbackDict):
+    __slots__ = ("modified",)
+
+    def __init__(self, *args, **kwargs):
+        def on_update(self):
+            self.modified = True
+
+        self.modified = False
+        CallbackDict.__init__(self, on_update=on_update)
+        dict.update(self, *args, **kwargs)
+
+    def copy(self):
+        """Create a flat copy of the dict."""
+        missing = object()
+        result = object.__new__(self.__class__)
+        for name in self.__slots__:
+            val = getattr(self, name, missing)
+            if val is not missing:
+                setattr(result, name, val)
+        return result
+
+    def __copy__(self):
+        return self.copy()
+
+
+class Session(ModificationTrackingDict):
+    """Subclass of a dict that keeps track of direct object changes.  Changes
+    in mutable structures are not tracked, for those you have to set
+    `modified` to `True` by hand.
+    """
+
+    __slots__ = ModificationTrackingDict.__slots__ + ("sid", "new")
+
+    def __init__(self, data, sid, new=False):
+        ModificationTrackingDict.__init__(self, data)
+        self.sid = sid
+        self.new = new
+
+    def __repr__(self):
+        return "<%s %s%s>" % (
+            self.__class__.__name__,
+            dict.__repr__(self),
+            "*" if self.should_save else "",
+        )
+
+    @property
+    def should_save(self):
+        """True if the session should be saved.
+
+        .. versionchanged:: 0.6
+           By default the session is now only saved if the session is
+           modified, not if it is new like it was before.
+        """
+        return self.modified
+
+
+class SessionStore(object):
+    """Baseclass for all session stores.  The Werkzeug contrib module does not
+    implement any useful stores besides the filesystem store, application
+    developers are encouraged to create their own stores.
+
+    :param session_class: The session class to use.  Defaults to
+                          :class:`Session`.
+    """
+
+    def __init__(self, session_class=None):
+        if session_class is None:
+            session_class = Session
+        self.session_class = session_class
+
+    def is_valid_key(self, key):
+        """Check if a key has the correct format."""
+        return _sha1_re.match(key) is not None
+
+    def generate_key(self, salt=None):
+        """Simple function that generates a new session key."""
+        return generate_key(salt)
+
+    def new(self):
+        """Generate a new session."""
+        return self.session_class({}, self.generate_key(), True)
+
+    def save(self, session):
+        """Save a session."""
+
+    def save_if_modified(self, session):
+        """Save if a session class wants an update."""
+        if session.should_save:
+            self.save(session)
+
+    def delete(self, session):
+        """Delete a session."""
+
+    def get(self, sid):
+        """Get a session for this sid or a new session object.  This method
+        has to check if the session key is valid and create a new session if
+        that wasn't the case.
+        """
+        return self.session_class({}, sid, True)
+
+
+#: used for temporary files by the filesystem session store
+_fs_transaction_suffix = ".__wz_sess"
+
+
+class FilesystemSessionStore(SessionStore):
+    """Simple example session store that saves sessions on the filesystem.
+    This store works best on POSIX systems and Windows Vista / Windows
+    Server 2008 and newer.
+
+    .. versionchanged:: 0.6
+       `renew_missing` was added.  Previously this was considered `True`,
+       now the default changed to `False` and it can be explicitly
+       deactivated.
+
+    :param path: the path to the folder used for storing the sessions.
+                 If not provided the default temporary directory is used.
+    :param filename_template: a string template used to give the session
+                              a filename.  ``%s`` is replaced with the
+                              session id.
+    :param session_class: The session class to use.  Defaults to
+                          :class:`Session`.
+    :param renew_missing: set to `True` if you want the store to
+                          give the user a new sid if the session was
+                          not yet saved.
+    """
+
+    def __init__(
+        self,
+        path=None,
+        filename_template="werkzeug_%s.sess",
+        session_class=None,
+        renew_missing=False,
+        mode=0o644,
+    ):
+        SessionStore.__init__(self, session_class)
+        if path is None:
+            path = tempfile.gettempdir()
+        self.path = path
+        if isinstance(filename_template, text_type) and PY2:
+            filename_template = filename_template.encode(get_filesystem_encoding())
+        assert not filename_template.endswith(_fs_transaction_suffix), (
+            "filename templates may not end with %s" % _fs_transaction_suffix
+        )
+        self.filename_template = filename_template
+        self.renew_missing = renew_missing
+        self.mode = mode
+
+    def get_session_filename(self, sid):
+        # out of the box, this should be a strict ASCII subset but
+        # you might reconfigure the session object to have a more
+        # arbitrary string.
+        if isinstance(sid, text_type) and PY2:
+            sid = sid.encode(get_filesystem_encoding())
+        return path.join(self.path, self.filename_template % sid)
+
+    def save(self, session):
+        fn = self.get_session_filename(session.sid)
+        fd, tmp = tempfile.mkstemp(suffix=_fs_transaction_suffix, dir=self.path)
+        f = os.fdopen(fd, "wb")
+        try:
+            dump(dict(session), f, HIGHEST_PROTOCOL)
+        finally:
+            f.close()
+        try:
+            rename(tmp, fn)
+            os.chmod(fn, self.mode)
+        except (IOError, OSError):
+            pass
+
+    def delete(self, session):
+        fn = self.get_session_filename(session.sid)
+        try:
+            os.unlink(fn)
+        except OSError:
+            pass
+
+    def get(self, sid):
+        if not self.is_valid_key(sid):
+            return self.new()
+        try:
+            f = open(self.get_session_filename(sid), "rb")
+        except IOError:
+            if self.renew_missing:
+                return self.new()
+            data = {}
+        else:
+            try:
+                try:
+                    data = load(f)
+                except Exception:
+                    data = {}
+            finally:
+                f.close()
+        return self.session_class(data, sid, False)
+
+    def list(self):
+        """Lists all sessions in the store.
+
+        .. versionadded:: 0.6
+        """
+        before, after = self.filename_template.split("%s", 1)
+        filename_re = re.compile(
+            r"%s(.{5,})%s$" % (re.escape(before), re.escape(after))
+        )
+        result = []
+        for filename in os.listdir(self.path):
+            #: this is a session that is still being saved.
+            if filename.endswith(_fs_transaction_suffix):
+                continue
+            match = filename_re.match(filename)
+            if match is not None:
+                result.append(match.group(1))
+        return result
+
+
+class SessionMiddleware(object):
+    """A simple middleware that puts the session object of a store provided
+    into the WSGI environ.  It automatically sets cookies and restores
+    sessions.
+
+    However a middleware is not the preferred solution because it won't be as
+    fast as sessions managed by the application itself and will put a key into
+    the WSGI environment only relevant for the application which is against
+    the concept of WSGI.
+
+    The cookie parameters are the same as for the :func:`~dump_cookie`
+    function just prefixed with ``cookie_``.  Additionally `max_age` is
+    called `cookie_age` and not `cookie_max_age` because of backwards
+    compatibility.
+    """
+
+    def __init__(
+        self,
+        app,
+        store,
+        cookie_name="session_id",
+        cookie_age=None,
+        cookie_expires=None,
+        cookie_path="/",
+        cookie_domain=None,
+        cookie_secure=None,
+        cookie_httponly=False,
+        cookie_samesite="Lax",
+        environ_key="werkzeug.session",
+    ):
+        self.app = app
+        self.store = store
+        self.cookie_name = cookie_name
+        self.cookie_age = cookie_age
+        self.cookie_expires = cookie_expires
+        self.cookie_path = cookie_path
+        self.cookie_domain = cookie_domain
+        self.cookie_secure = cookie_secure
+        self.cookie_httponly = cookie_httponly
+        self.cookie_samesite = cookie_samesite
+        self.environ_key = environ_key
+
+    def __call__(self, environ, start_response):
+        cookie = parse_cookie(environ.get("HTTP_COOKIE", ""))
+        sid = cookie.get(self.cookie_name, None)
+        if sid is None:
+            session = self.store.new()
+        else:
+            session = self.store.get(sid)
+        environ[self.environ_key] = session
+
+        def injecting_start_response(status, headers, exc_info=None):
+            if session.should_save:
+                self.store.save(session)
+                headers.append(
+                    (
+                        "Set-Cookie",
+                        dump_cookie(
+                            self.cookie_name,
+                            session.sid,
+                            self.cookie_age,
+                            self.cookie_expires,
+                            self.cookie_path,
+                            self.cookie_domain,
+                            self.cookie_secure,
+                            self.cookie_httponly,
+                            samesite=self.cookie_samesite,
+                        ),
+                    )
+                )
+            return start_response(status, headers, exc_info)
+
+        return ClosingIterator(
+            self.app(environ, injecting_start_response),
+            lambda: self.store.save_if_modified(session),
+        )
diff --git a/python/werkzeug/contrib/wrappers.py b/python/werkzeug/contrib/wrappers.py
new file mode 100644
index 0000000..49b82a7
--- /dev/null
+++ b/python/werkzeug/contrib/wrappers.py
@@ -0,0 +1,385 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.contrib.wrappers
+    ~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    Extra wrappers or mixins contributed by the community.  These wrappers can
+    be mixed in into request objects to add extra functionality.
+
+    Example::
+
+        from werkzeug.wrappers import Request as RequestBase
+        from werkzeug.contrib.wrappers import JSONRequestMixin
+
+        class Request(RequestBase, JSONRequestMixin):
+            pass
+
+    Afterwards this request object provides the extra functionality of the
+    :class:`JSONRequestMixin`.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import codecs
+import warnings
+
+from .._compat import wsgi_decoding_dance
+from ..exceptions import BadRequest
+from ..http import dump_options_header
+from ..http import parse_options_header
+from ..utils import cached_property
+from ..wrappers.json import JSONMixin as _JSONMixin
+
+
+def is_known_charset(charset):
+    """Checks if the given charset is known to Python."""
+    try:
+        codecs.lookup(charset)
+    except LookupError:
+        return False
+    return True
+
+
+class JSONRequestMixin(_JSONMixin):
+    """
+    .. deprecated:: 0.15
+        Moved to :class:`werkzeug.wrappers.json.JSONMixin`. This old
+        import will be removed in version 1.0.
+    """
+
+    @property
+    def json(self):
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.JSONRequestMixin' has moved to"
+            " 'werkzeug.wrappers.json.JSONMixin'. This old import will"
+            " be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return super(JSONRequestMixin, self).json
+
+
+class ProtobufRequestMixin(object):
+
+    """Add protobuf parsing method to a request object.  This will parse the
+    input data through `protobuf`_ if possible.
+
+    :exc:`~werkzeug.exceptions.BadRequest` will be raised if the content-type
+    is not protobuf or if the data itself cannot be parsed property.
+
+    .. _protobuf: https://github.com/protocolbuffers/protobuf
+
+    .. deprecated:: 0.15
+        This mixin will be removed in version 1.0.
+    """
+
+    #: by default the :class:`ProtobufRequestMixin` will raise a
+    #: :exc:`~werkzeug.exceptions.BadRequest` if the object is not
+    #: initialized.  You can bypass that check by setting this
+    #: attribute to `False`.
+    protobuf_check_initialization = True
+
+    def parse_protobuf(self, proto_type):
+        """Parse the data into an instance of proto_type."""
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.ProtobufRequestMixin' is"
+            " deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        if "protobuf" not in self.environ.get("CONTENT_TYPE", ""):
+            raise BadRequest("Not a Protobuf request")
+
+        obj = proto_type()
+        try:
+            obj.ParseFromString(self.data)
+        except Exception:
+            raise BadRequest("Unable to parse Protobuf request")
+
+        # Fail if not all required fields are set
+        if self.protobuf_check_initialization and not obj.IsInitialized():
+            raise BadRequest("Partial Protobuf request")
+
+        return obj
+
+
+class RoutingArgsRequestMixin(object):
+
+    """This request mixin adds support for the wsgiorg routing args
+    `specification`_.
+
+    .. _specification: https://wsgi.readthedocs.io/en/latest/
+       specifications/routing_args.html
+
+    .. deprecated:: 0.15
+        This mixin will be removed in version 1.0.
+    """
+
+    def _get_routing_args(self):
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.RoutingArgsRequestMixin' is"
+            " deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return self.environ.get("wsgiorg.routing_args", (()))[0]
+
+    def _set_routing_args(self, value):
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.RoutingArgsRequestMixin' is"
+            " deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        if self.shallow:
+            raise RuntimeError(
+                "A shallow request tried to modify the WSGI "
+                "environment.  If you really want to do that, "
+                "set `shallow` to False."
+            )
+        self.environ["wsgiorg.routing_args"] = (value, self.routing_vars)
+
+    routing_args = property(
+        _get_routing_args,
+        _set_routing_args,
+        doc="""
+        The positional URL arguments as `tuple`.""",
+    )
+    del _get_routing_args, _set_routing_args
+
+    def _get_routing_vars(self):
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.RoutingArgsRequestMixin' is"
+            " deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        rv = self.environ.get("wsgiorg.routing_args")
+        if rv is not None:
+            return rv[1]
+        rv = {}
+        if not self.shallow:
+            self.routing_vars = rv
+        return rv
+
+    def _set_routing_vars(self, value):
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.RoutingArgsRequestMixin' is"
+            " deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        if self.shallow:
+            raise RuntimeError(
+                "A shallow request tried to modify the WSGI "
+                "environment.  If you really want to do that, "
+                "set `shallow` to False."
+            )
+        self.environ["wsgiorg.routing_args"] = (self.routing_args, value)
+
+    routing_vars = property(
+        _get_routing_vars,
+        _set_routing_vars,
+        doc="""
+        The keyword URL arguments as `dict`.""",
+    )
+    del _get_routing_vars, _set_routing_vars
+
+
+class ReverseSlashBehaviorRequestMixin(object):
+
+    """This mixin reverses the trailing slash behavior of :attr:`script_root`
+    and :attr:`path`.  This makes it possible to use :func:`~urlparse.urljoin`
+    directly on the paths.
+
+    Because it changes the behavior or :class:`Request` this class has to be
+    mixed in *before* the actual request class::
+
+        class MyRequest(ReverseSlashBehaviorRequestMixin, Request):
+            pass
+
+    This example shows the differences (for an application mounted on
+    `/application` and the request going to `/application/foo/bar`):
+
+        +---------------+-------------------+---------------------+
+        |               | normal behavior   | reverse behavior    |
+        +===============+===================+=====================+
+        | `script_root` | ``/application``  | ``/application/``   |
+        +---------------+-------------------+---------------------+
+        | `path`        | ``/foo/bar``      | ``foo/bar``         |
+        +---------------+-------------------+---------------------+
+
+    .. deprecated:: 0.15
+        This mixin will be removed in version 1.0.
+    """
+
+    @cached_property
+    def path(self):
+        """Requested path as unicode.  This works a bit like the regular path
+        info in the WSGI environment but will not include a leading slash.
+        """
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.ReverseSlashBehaviorRequestMixin'"
+            " is deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        path = wsgi_decoding_dance(
+            self.environ.get("PATH_INFO") or "", self.charset, self.encoding_errors
+        )
+        return path.lstrip("/")
+
+    @cached_property
+    def script_root(self):
+        """The root path of the script includling a trailing slash."""
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.ReverseSlashBehaviorRequestMixin'"
+            " is deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        path = wsgi_decoding_dance(
+            self.environ.get("SCRIPT_NAME") or "", self.charset, self.encoding_errors
+        )
+        return path.rstrip("/") + "/"
+
+
+class DynamicCharsetRequestMixin(object):
+
+    """"If this mixin is mixed into a request class it will provide
+    a dynamic `charset` attribute.  This means that if the charset is
+    transmitted in the content type headers it's used from there.
+
+    Because it changes the behavior or :class:`Request` this class has
+    to be mixed in *before* the actual request class::
+
+        class MyRequest(DynamicCharsetRequestMixin, Request):
+            pass
+
+    By default the request object assumes that the URL charset is the
+    same as the data charset.  If the charset varies on each request
+    based on the transmitted data it's not a good idea to let the URLs
+    change based on that.  Most browsers assume either utf-8 or latin1
+    for the URLs if they have troubles figuring out.  It's strongly
+    recommended to set the URL charset to utf-8::
+
+        class MyRequest(DynamicCharsetRequestMixin, Request):
+            url_charset = 'utf-8'
+
+    .. deprecated:: 0.15
+        This mixin will be removed in version 1.0.
+
+    .. versionadded:: 0.6
+    """
+
+    #: the default charset that is assumed if the content type header
+    #: is missing or does not contain a charset parameter.  The default
+    #: is latin1 which is what HTTP specifies as default charset.
+    #: You may however want to set this to utf-8 to better support
+    #: browsers that do not transmit a charset for incoming data.
+    default_charset = "latin1"
+
+    def unknown_charset(self, charset):
+        """Called if a charset was provided but is not supported by
+        the Python codecs module.  By default latin1 is assumed then
+        to not lose any information, you may override this method to
+        change the behavior.
+
+        :param charset: the charset that was not found.
+        :return: the replacement charset.
+        """
+        return "latin1"
+
+    @cached_property
+    def charset(self):
+        """The charset from the content type."""
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.DynamicCharsetRequestMixin'"
+            " is deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        header = self.environ.get("CONTENT_TYPE")
+        if header:
+            ct, options = parse_options_header(header)
+            charset = options.get("charset")
+            if charset:
+                if is_known_charset(charset):
+                    return charset
+                return self.unknown_charset(charset)
+        return self.default_charset
+
+
+class DynamicCharsetResponseMixin(object):
+
+    """If this mixin is mixed into a response class it will provide
+    a dynamic `charset` attribute.  This means that if the charset is
+    looked up and stored in the `Content-Type` header and updates
+    itself automatically.  This also means a small performance hit but
+    can be useful if you're working with different charsets on
+    responses.
+
+    Because the charset attribute is no a property at class-level, the
+    default value is stored in `default_charset`.
+
+    Because it changes the behavior or :class:`Response` this class has
+    to be mixed in *before* the actual response class::
+
+        class MyResponse(DynamicCharsetResponseMixin, Response):
+            pass
+
+    .. deprecated:: 0.15
+        This mixin will be removed in version 1.0.
+
+    .. versionadded:: 0.6
+    """
+
+    #: the default charset.
+    default_charset = "utf-8"
+
+    def _get_charset(self):
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.DynamicCharsetResponseMixin'"
+            " is deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        header = self.headers.get("content-type")
+        if header:
+            charset = parse_options_header(header)[1].get("charset")
+            if charset:
+                return charset
+        return self.default_charset
+
+    def _set_charset(self, charset):
+        warnings.warn(
+            "'werkzeug.contrib.wrappers.DynamicCharsetResponseMixin'"
+            " is deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        header = self.headers.get("content-type")
+        ct, options = parse_options_header(header)
+        if not ct:
+            raise TypeError("Cannot set charset if Content-Type header is missing.")
+        options["charset"] = charset
+        self.headers["Content-Type"] = dump_options_header(ct, options)
+
+    charset = property(
+        _get_charset,
+        _set_charset,
+        doc="""
+        The charset for the response.  It's stored inside the
+        Content-Type header as a parameter.""",
+    )
+    del _get_charset, _set_charset
diff --git a/python/werkzeug/datastructures.py b/python/werkzeug/datastructures.py
new file mode 100644
index 0000000..9643db9
--- /dev/null
+++ b/python/werkzeug/datastructures.py
@@ -0,0 +1,2852 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.datastructures
+    ~~~~~~~~~~~~~~~~~~~~~~~
+
+    This module provides mixins and classes with an immutable interface.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import codecs
+import mimetypes
+import re
+from copy import deepcopy
+from itertools import repeat
+
+from ._compat import BytesIO
+from ._compat import collections_abc
+from ._compat import integer_types
+from ._compat import iteritems
+from ._compat import iterkeys
+from ._compat import iterlists
+from ._compat import itervalues
+from ._compat import make_literal_wrapper
+from ._compat import PY2
+from ._compat import string_types
+from ._compat import text_type
+from ._compat import to_native
+from ._internal import _missing
+from .filesystem import get_filesystem_encoding
+
+_locale_delim_re = re.compile(r"[_-]")
+
+
+def is_immutable(self):
+    raise TypeError("%r objects are immutable" % self.__class__.__name__)
+
+
+def iter_multi_items(mapping):
+    """Iterates over the items of a mapping yielding keys and values
+    without dropping any from more complex structures.
+    """
+    if isinstance(mapping, MultiDict):
+        for item in iteritems(mapping, multi=True):
+            yield item
+    elif isinstance(mapping, dict):
+        for key, value in iteritems(mapping):
+            if isinstance(value, (tuple, list)):
+                for value in value:
+                    yield key, value
+            else:
+                yield key, value
+    else:
+        for item in mapping:
+            yield item
+
+
+def native_itermethods(names):
+    if not PY2:
+        return lambda x: x
+
+    def setviewmethod(cls, name):
+        viewmethod_name = "view%s" % name
+        repr_name = "view_%s" % name
+
+        def viewmethod(self, *a, **kw):
+            return ViewItems(self, name, repr_name, *a, **kw)
+
+        viewmethod.__name__ = viewmethod_name
+        viewmethod.__doc__ = "`%s()` object providing a view on %s" % (
+            viewmethod_name,
+            name,
+        )
+        setattr(cls, viewmethod_name, viewmethod)
+
+    def setitermethod(cls, name):
+        itermethod = getattr(cls, name)
+        setattr(cls, "iter%s" % name, itermethod)
+
+        def listmethod(self, *a, **kw):
+            return list(itermethod(self, *a, **kw))
+
+        listmethod.__name__ = name
+        listmethod.__doc__ = "Like :py:meth:`iter%s`, but returns a list." % name
+        setattr(cls, name, listmethod)
+
+    def wrap(cls):
+        for name in names:
+            setitermethod(cls, name)
+            setviewmethod(cls, name)
+        return cls
+
+    return wrap
+
+
+class ImmutableListMixin(object):
+    """Makes a :class:`list` immutable.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    _hash_cache = None
+
+    def __hash__(self):
+        if self._hash_cache is not None:
+            return self._hash_cache
+        rv = self._hash_cache = hash(tuple(self))
+        return rv
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (list(self),)
+
+    def __delitem__(self, key):
+        is_immutable(self)
+
+    def __iadd__(self, other):
+        is_immutable(self)
+
+    __imul__ = __iadd__
+
+    def __setitem__(self, key, value):
+        is_immutable(self)
+
+    def append(self, item):
+        is_immutable(self)
+
+    remove = append
+
+    def extend(self, iterable):
+        is_immutable(self)
+
+    def insert(self, pos, value):
+        is_immutable(self)
+
+    def pop(self, index=-1):
+        is_immutable(self)
+
+    def reverse(self):
+        is_immutable(self)
+
+    def sort(self, cmp=None, key=None, reverse=None):
+        is_immutable(self)
+
+
+class ImmutableList(ImmutableListMixin, list):
+    """An immutable :class:`list`.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    def __repr__(self):
+        return "%s(%s)" % (self.__class__.__name__, list.__repr__(self))
+
+
+class ImmutableDictMixin(object):
+    """Makes a :class:`dict` immutable.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    _hash_cache = None
+
+    @classmethod
+    def fromkeys(cls, keys, value=None):
+        instance = super(cls, cls).__new__(cls)
+        instance.__init__(zip(keys, repeat(value)))
+        return instance
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (dict(self),)
+
+    def _iter_hashitems(self):
+        return iteritems(self)
+
+    def __hash__(self):
+        if self._hash_cache is not None:
+            return self._hash_cache
+        rv = self._hash_cache = hash(frozenset(self._iter_hashitems()))
+        return rv
+
+    def setdefault(self, key, default=None):
+        is_immutable(self)
+
+    def update(self, *args, **kwargs):
+        is_immutable(self)
+
+    def pop(self, key, default=None):
+        is_immutable(self)
+
+    def popitem(self):
+        is_immutable(self)
+
+    def __setitem__(self, key, value):
+        is_immutable(self)
+
+    def __delitem__(self, key):
+        is_immutable(self)
+
+    def clear(self):
+        is_immutable(self)
+
+
+class ImmutableMultiDictMixin(ImmutableDictMixin):
+    """Makes a :class:`MultiDict` immutable.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (list(iteritems(self, multi=True)),)
+
+    def _iter_hashitems(self):
+        return iteritems(self, multi=True)
+
+    def add(self, key, value):
+        is_immutable(self)
+
+    def popitemlist(self):
+        is_immutable(self)
+
+    def poplist(self, key):
+        is_immutable(self)
+
+    def setlist(self, key, new_list):
+        is_immutable(self)
+
+    def setlistdefault(self, key, default_list=None):
+        is_immutable(self)
+
+
+class UpdateDictMixin(object):
+    """Makes dicts call `self.on_update` on modifications.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    on_update = None
+
+    def calls_update(name):  # noqa: B902
+        def oncall(self, *args, **kw):
+            rv = getattr(super(UpdateDictMixin, self), name)(*args, **kw)
+            if self.on_update is not None:
+                self.on_update(self)
+            return rv
+
+        oncall.__name__ = name
+        return oncall
+
+    def setdefault(self, key, default=None):
+        modified = key not in self
+        rv = super(UpdateDictMixin, self).setdefault(key, default)
+        if modified and self.on_update is not None:
+            self.on_update(self)
+        return rv
+
+    def pop(self, key, default=_missing):
+        modified = key in self
+        if default is _missing:
+            rv = super(UpdateDictMixin, self).pop(key)
+        else:
+            rv = super(UpdateDictMixin, self).pop(key, default)
+        if modified and self.on_update is not None:
+            self.on_update(self)
+        return rv
+
+    __setitem__ = calls_update("__setitem__")
+    __delitem__ = calls_update("__delitem__")
+    clear = calls_update("clear")
+    popitem = calls_update("popitem")
+    update = calls_update("update")
+    del calls_update
+
+
+class TypeConversionDict(dict):
+    """Works like a regular dict but the :meth:`get` method can perform
+    type conversions.  :class:`MultiDict` and :class:`CombinedMultiDict`
+    are subclasses of this class and provide the same feature.
+
+    .. versionadded:: 0.5
+    """
+
+    def get(self, key, default=None, type=None):
+        """Return the default value if the requested data doesn't exist.
+        If `type` is provided and is a callable it should convert the value,
+        return it or raise a :exc:`ValueError` if that is not possible.  In
+        this case the function will return the default as if the value was not
+        found:
+
+        >>> d = TypeConversionDict(foo='42', bar='blub')
+        >>> d.get('foo', type=int)
+        42
+        >>> d.get('bar', -1, type=int)
+        -1
+
+        :param key: The key to be looked up.
+        :param default: The default value to be returned if the key can't
+                        be looked up.  If not further specified `None` is
+                        returned.
+        :param type: A callable that is used to cast the value in the
+                     :class:`MultiDict`.  If a :exc:`ValueError` is raised
+                     by this callable the default value is returned.
+        """
+        try:
+            rv = self[key]
+        except KeyError:
+            return default
+        if type is not None:
+            try:
+                rv = type(rv)
+            except ValueError:
+                rv = default
+        return rv
+
+
+class ImmutableTypeConversionDict(ImmutableDictMixin, TypeConversionDict):
+    """Works like a :class:`TypeConversionDict` but does not support
+    modifications.
+
+    .. versionadded:: 0.5
+    """
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return TypeConversionDict(self)
+
+    def __copy__(self):
+        return self
+
+
+class ViewItems(object):
+    def __init__(self, multi_dict, method, repr_name, *a, **kw):
+        self.__multi_dict = multi_dict
+        self.__method = method
+        self.__repr_name = repr_name
+        self.__a = a
+        self.__kw = kw
+
+    def __get_items(self):
+        return getattr(self.__multi_dict, self.__method)(*self.__a, **self.__kw)
+
+    def __repr__(self):
+        return "%s(%r)" % (self.__repr_name, list(self.__get_items()))
+
+    def __iter__(self):
+        return iter(self.__get_items())
+
+
+@native_itermethods(["keys", "values", "items", "lists", "listvalues"])
+class MultiDict(TypeConversionDict):
+    """A :class:`MultiDict` is a dictionary subclass customized to deal with
+    multiple values for the same key which is for example used by the parsing
+    functions in the wrappers.  This is necessary because some HTML form
+    elements pass multiple values for the same key.
+
+    :class:`MultiDict` implements all standard dictionary methods.
+    Internally, it saves all values for a key as a list, but the standard dict
+    access methods will only return the first value for a key. If you want to
+    gain access to the other values, too, you have to use the `list` methods as
+    explained below.
+
+    Basic Usage:
+
+    >>> d = MultiDict([('a', 'b'), ('a', 'c')])
+    >>> d
+    MultiDict([('a', 'b'), ('a', 'c')])
+    >>> d['a']
+    'b'
+    >>> d.getlist('a')
+    ['b', 'c']
+    >>> 'a' in d
+    True
+
+    It behaves like a normal dict thus all dict functions will only return the
+    first value when multiple values for one key are found.
+
+    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
+    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
+    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for HTTP
+    exceptions.
+
+    A :class:`MultiDict` can be constructed from an iterable of
+    ``(key, value)`` tuples, a dict, a :class:`MultiDict` or from Werkzeug 0.2
+    onwards some keyword parameters.
+
+    :param mapping: the initial value for the :class:`MultiDict`.  Either a
+                    regular dict, an iterable of ``(key, value)`` tuples
+                    or `None`.
+    """
+
+    def __init__(self, mapping=None):
+        if isinstance(mapping, MultiDict):
+            dict.__init__(self, ((k, l[:]) for k, l in iterlists(mapping)))
+        elif isinstance(mapping, dict):
+            tmp = {}
+            for key, value in iteritems(mapping):
+                if isinstance(value, (tuple, list)):
+                    if len(value) == 0:
+                        continue
+                    value = list(value)
+                else:
+                    value = [value]
+                tmp[key] = value
+            dict.__init__(self, tmp)
+        else:
+            tmp = {}
+            for key, value in mapping or ():
+                tmp.setdefault(key, []).append(value)
+            dict.__init__(self, tmp)
+
+    def __getstate__(self):
+        return dict(self.lists())
+
+    def __setstate__(self, value):
+        dict.clear(self)
+        dict.update(self, value)
+
+    def __getitem__(self, key):
+        """Return the first data value for this key;
+        raises KeyError if not found.
+
+        :param key: The key to be looked up.
+        :raise KeyError: if the key does not exist.
+        """
+
+        if key in self:
+            lst = dict.__getitem__(self, key)
+            if len(lst) > 0:
+                return lst[0]
+        raise exceptions.BadRequestKeyError(key)
+
+    def __setitem__(self, key, value):
+        """Like :meth:`add` but removes an existing key first.
+
+        :param key: the key for the value.
+        :param value: the value to set.
+        """
+        dict.__setitem__(self, key, [value])
+
+    def add(self, key, value):
+        """Adds a new value for the key.
+
+        .. versionadded:: 0.6
+
+        :param key: the key for the value.
+        :param value: the value to add.
+        """
+        dict.setdefault(self, key, []).append(value)
+
+    def getlist(self, key, type=None):
+        """Return the list of items for a given key. If that key is not in the
+        `MultiDict`, the return value will be an empty list.  Just as `get`
+        `getlist` accepts a `type` parameter.  All items will be converted
+        with the callable defined there.
+
+        :param key: The key to be looked up.
+        :param type: A callable that is used to cast the value in the
+                     :class:`MultiDict`.  If a :exc:`ValueError` is raised
+                     by this callable the value will be removed from the list.
+        :return: a :class:`list` of all the values for the key.
+        """
+        try:
+            rv = dict.__getitem__(self, key)
+        except KeyError:
+            return []
+        if type is None:
+            return list(rv)
+        result = []
+        for item in rv:
+            try:
+                result.append(type(item))
+            except ValueError:
+                pass
+        return result
+
+    def setlist(self, key, new_list):
+        """Remove the old values for a key and add new ones.  Note that the list
+        you pass the values in will be shallow-copied before it is inserted in
+        the dictionary.
+
+        >>> d = MultiDict()
+        >>> d.setlist('foo', ['1', '2'])
+        >>> d['foo']
+        '1'
+        >>> d.getlist('foo')
+        ['1', '2']
+
+        :param key: The key for which the values are set.
+        :param new_list: An iterable with the new values for the key.  Old values
+                         are removed first.
+        """
+        dict.__setitem__(self, key, list(new_list))
+
+    def setdefault(self, key, default=None):
+        """Returns the value for the key if it is in the dict, otherwise it
+        returns `default` and sets that value for `key`.
+
+        :param key: The key to be looked up.
+        :param default: The default value to be returned if the key is not
+                        in the dict.  If not further specified it's `None`.
+        """
+        if key not in self:
+            self[key] = default
+        else:
+            default = self[key]
+        return default
+
+    def setlistdefault(self, key, default_list=None):
+        """Like `setdefault` but sets multiple values.  The list returned
+        is not a copy, but the list that is actually used internally.  This
+        means that you can put new values into the dict by appending items
+        to the list:
+
+        >>> d = MultiDict({"foo": 1})
+        >>> d.setlistdefault("foo").extend([2, 3])
+        >>> d.getlist("foo")
+        [1, 2, 3]
+
+        :param key: The key to be looked up.
+        :param default_list: An iterable of default values.  It is either copied
+                             (in case it was a list) or converted into a list
+                             before returned.
+        :return: a :class:`list`
+        """
+        if key not in self:
+            default_list = list(default_list or ())
+            dict.__setitem__(self, key, default_list)
+        else:
+            default_list = dict.__getitem__(self, key)
+        return default_list
+
+    def items(self, multi=False):
+        """Return an iterator of ``(key, value)`` pairs.
+
+        :param multi: If set to `True` the iterator returned will have a pair
+                      for each value of each key.  Otherwise it will only
+                      contain pairs for the first value of each key.
+        """
+
+        for key, values in iteritems(dict, self):
+            if multi:
+                for value in values:
+                    yield key, value
+            else:
+                yield key, values[0]
+
+    def lists(self):
+        """Return a iterator of ``(key, values)`` pairs, where values is the list
+        of all values associated with the key."""
+
+        for key, values in iteritems(dict, self):
+            yield key, list(values)
+
+    def keys(self):
+        return iterkeys(dict, self)
+
+    __iter__ = keys
+
+    def values(self):
+        """Returns an iterator of the first value on every key's value list."""
+        for values in itervalues(dict, self):
+            yield values[0]
+
+    def listvalues(self):
+        """Return an iterator of all values associated with a key.  Zipping
+        :meth:`keys` and this is the same as calling :meth:`lists`:
+
+        >>> d = MultiDict({"foo": [1, 2, 3]})
+        >>> zip(d.keys(), d.listvalues()) == d.lists()
+        True
+        """
+
+        return itervalues(dict, self)
+
+    def copy(self):
+        """Return a shallow copy of this object."""
+        return self.__class__(self)
+
+    def deepcopy(self, memo=None):
+        """Return a deep copy of this object."""
+        return self.__class__(deepcopy(self.to_dict(flat=False), memo))
+
+    def to_dict(self, flat=True):
+        """Return the contents as regular dict.  If `flat` is `True` the
+        returned dict will only have the first item present, if `flat` is
+        `False` all values will be returned as lists.
+
+        :param flat: If set to `False` the dict returned will have lists
+                     with all the values in it.  Otherwise it will only
+                     contain the first value for each key.
+        :return: a :class:`dict`
+        """
+        if flat:
+            return dict(iteritems(self))
+        return dict(self.lists())
+
+    def update(self, other_dict):
+        """update() extends rather than replaces existing key lists:
+
+        >>> a = MultiDict({'x': 1})
+        >>> b = MultiDict({'x': 2, 'y': 3})
+        >>> a.update(b)
+        >>> a
+        MultiDict([('y', 3), ('x', 1), ('x', 2)])
+
+        If the value list for a key in ``other_dict`` is empty, no new values
+        will be added to the dict and the key will not be created:
+
+        >>> x = {'empty_list': []}
+        >>> y = MultiDict()
+        >>> y.update(x)
+        >>> y
+        MultiDict([])
+        """
+        for key, value in iter_multi_items(other_dict):
+            MultiDict.add(self, key, value)
+
+    def pop(self, key, default=_missing):
+        """Pop the first item for a list on the dict.  Afterwards the
+        key is removed from the dict, so additional values are discarded:
+
+        >>> d = MultiDict({"foo": [1, 2, 3]})
+        >>> d.pop("foo")
+        1
+        >>> "foo" in d
+        False
+
+        :param key: the key to pop.
+        :param default: if provided the value to return if the key was
+                        not in the dictionary.
+        """
+        try:
+            lst = dict.pop(self, key)
+
+            if len(lst) == 0:
+                raise exceptions.BadRequestKeyError(key)
+
+            return lst[0]
+        except KeyError:
+            if default is not _missing:
+                return default
+            raise exceptions.BadRequestKeyError(key)
+
+    def popitem(self):
+        """Pop an item from the dict."""
+        try:
+            item = dict.popitem(self)
+
+            if len(item[1]) == 0:
+                raise exceptions.BadRequestKeyError(item)
+
+            return (item[0], item[1][0])
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0])
+
+    def poplist(self, key):
+        """Pop the list for a key from the dict.  If the key is not in the dict
+        an empty list is returned.
+
+        .. versionchanged:: 0.5
+           If the key does no longer exist a list is returned instead of
+           raising an error.
+        """
+        return dict.pop(self, key, [])
+
+    def popitemlist(self):
+        """Pop a ``(key, list)`` tuple from the dict."""
+        try:
+            return dict.popitem(self)
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0])
+
+    def __copy__(self):
+        return self.copy()
+
+    def __deepcopy__(self, memo):
+        return self.deepcopy(memo=memo)
+
+    def __repr__(self):
+        return "%s(%r)" % (self.__class__.__name__, list(iteritems(self, multi=True)))
+
+
+class _omd_bucket(object):
+    """Wraps values in the :class:`OrderedMultiDict`.  This makes it
+    possible to keep an order over multiple different keys.  It requires
+    a lot of extra memory and slows down access a lot, but makes it
+    possible to access elements in O(1) and iterate in O(n).
+    """
+
+    __slots__ = ("prev", "key", "value", "next")
+
+    def __init__(self, omd, key, value):
+        self.prev = omd._last_bucket
+        self.key = key
+        self.value = value
+        self.next = None
+
+        if omd._first_bucket is None:
+            omd._first_bucket = self
+        if omd._last_bucket is not None:
+            omd._last_bucket.next = self
+        omd._last_bucket = self
+
+    def unlink(self, omd):
+        if self.prev:
+            self.prev.next = self.next
+        if self.next:
+            self.next.prev = self.prev
+        if omd._first_bucket is self:
+            omd._first_bucket = self.next
+        if omd._last_bucket is self:
+            omd._last_bucket = self.prev
+
+
+@native_itermethods(["keys", "values", "items", "lists", "listvalues"])
+class OrderedMultiDict(MultiDict):
+    """Works like a regular :class:`MultiDict` but preserves the
+    order of the fields.  To convert the ordered multi dict into a
+    list you can use the :meth:`items` method and pass it ``multi=True``.
+
+    In general an :class:`OrderedMultiDict` is an order of magnitude
+    slower than a :class:`MultiDict`.
+
+    .. admonition:: note
+
+       Due to a limitation in Python you cannot convert an ordered
+       multi dict into a regular dict by using ``dict(multidict)``.
+       Instead you have to use the :meth:`to_dict` method, otherwise
+       the internal bucket objects are exposed.
+    """
+
+    def __init__(self, mapping=None):
+        dict.__init__(self)
+        self._first_bucket = self._last_bucket = None
+        if mapping is not None:
+            OrderedMultiDict.update(self, mapping)
+
+    def __eq__(self, other):
+        if not isinstance(other, MultiDict):
+            return NotImplemented
+        if isinstance(other, OrderedMultiDict):
+            iter1 = iteritems(self, multi=True)
+            iter2 = iteritems(other, multi=True)
+            try:
+                for k1, v1 in iter1:
+                    k2, v2 = next(iter2)
+                    if k1 != k2 or v1 != v2:
+                        return False
+            except StopIteration:
+                return False
+            try:
+                next(iter2)
+            except StopIteration:
+                return True
+            return False
+        if len(self) != len(other):
+            return False
+        for key, values in iterlists(self):
+            if other.getlist(key) != values:
+                return False
+        return True
+
+    __hash__ = None
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (list(iteritems(self, multi=True)),)
+
+    def __getstate__(self):
+        return list(iteritems(self, multi=True))
+
+    def __setstate__(self, values):
+        dict.clear(self)
+        for key, value in values:
+            self.add(key, value)
+
+    def __getitem__(self, key):
+        if key in self:
+            return dict.__getitem__(self, key)[0].value
+        raise exceptions.BadRequestKeyError(key)
+
+    def __setitem__(self, key, value):
+        self.poplist(key)
+        self.add(key, value)
+
+    def __delitem__(self, key):
+        self.pop(key)
+
+    def keys(self):
+        return (key for key, value in iteritems(self))
+
+    __iter__ = keys
+
+    def values(self):
+        return (value for key, value in iteritems(self))
+
+    def items(self, multi=False):
+        ptr = self._first_bucket
+        if multi:
+            while ptr is not None:
+                yield ptr.key, ptr.value
+                ptr = ptr.next
+        else:
+            returned_keys = set()
+            while ptr is not None:
+                if ptr.key not in returned_keys:
+                    returned_keys.add(ptr.key)
+                    yield ptr.key, ptr.value
+                ptr = ptr.next
+
+    def lists(self):
+        returned_keys = set()
+        ptr = self._first_bucket
+        while ptr is not None:
+            if ptr.key not in returned_keys:
+                yield ptr.key, self.getlist(ptr.key)
+                returned_keys.add(ptr.key)
+            ptr = ptr.next
+
+    def listvalues(self):
+        for _key, values in iterlists(self):
+            yield values
+
+    def add(self, key, value):
+        dict.setdefault(self, key, []).append(_omd_bucket(self, key, value))
+
+    def getlist(self, key, type=None):
+        try:
+            rv = dict.__getitem__(self, key)
+        except KeyError:
+            return []
+        if type is None:
+            return [x.value for x in rv]
+        result = []
+        for item in rv:
+            try:
+                result.append(type(item.value))
+            except ValueError:
+                pass
+        return result
+
+    def setlist(self, key, new_list):
+        self.poplist(key)
+        for value in new_list:
+            self.add(key, value)
+
+    def setlistdefault(self, key, default_list=None):
+        raise TypeError("setlistdefault is unsupported for ordered multi dicts")
+
+    def update(self, mapping):
+        for key, value in iter_multi_items(mapping):
+            OrderedMultiDict.add(self, key, value)
+
+    def poplist(self, key):
+        buckets = dict.pop(self, key, ())
+        for bucket in buckets:
+            bucket.unlink(self)
+        return [x.value for x in buckets]
+
+    def pop(self, key, default=_missing):
+        try:
+            buckets = dict.pop(self, key)
+        except KeyError:
+            if default is not _missing:
+                return default
+            raise exceptions.BadRequestKeyError(key)
+        for bucket in buckets:
+            bucket.unlink(self)
+        return buckets[0].value
+
+    def popitem(self):
+        try:
+            key, buckets = dict.popitem(self)
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0])
+        for bucket in buckets:
+            bucket.unlink(self)
+        return key, buckets[0].value
+
+    def popitemlist(self):
+        try:
+            key, buckets = dict.popitem(self)
+        except KeyError as e:
+            raise exceptions.BadRequestKeyError(e.args[0])
+        for bucket in buckets:
+            bucket.unlink(self)
+        return key, [x.value for x in buckets]
+
+
+def _options_header_vkw(value, kw):
+    return dump_options_header(
+        value, dict((k.replace("_", "-"), v) for k, v in kw.items())
+    )
+
+
+def _unicodify_header_value(value):
+    if isinstance(value, bytes):
+        value = value.decode("latin-1")
+    if not isinstance(value, text_type):
+        value = text_type(value)
+    return value
+
+
+@native_itermethods(["keys", "values", "items"])
+class Headers(object):
+    """An object that stores some headers.  It has a dict-like interface
+    but is ordered and can store the same keys multiple times.
+
+    This data structure is useful if you want a nicer way to handle WSGI
+    headers which are stored as tuples in a list.
+
+    From Werkzeug 0.3 onwards, the :exc:`KeyError` raised by this class is
+    also a subclass of the :class:`~exceptions.BadRequest` HTTP exception
+    and will render a page for a ``400 BAD REQUEST`` if caught in a
+    catch-all for HTTP exceptions.
+
+    Headers is mostly compatible with the Python :class:`wsgiref.headers.Headers`
+    class, with the exception of `__getitem__`.  :mod:`wsgiref` will return
+    `None` for ``headers['missing']``, whereas :class:`Headers` will raise
+    a :class:`KeyError`.
+
+    To create a new :class:`Headers` object pass it a list or dict of headers
+    which are used as default values.  This does not reuse the list passed
+    to the constructor for internal usage.
+
+    :param defaults: The list of default values for the :class:`Headers`.
+
+    .. versionchanged:: 0.9
+       This data structure now stores unicode values similar to how the
+       multi dicts do it.  The main difference is that bytes can be set as
+       well which will automatically be latin1 decoded.
+
+    .. versionchanged:: 0.9
+       The :meth:`linked` function was removed without replacement as it
+       was an API that does not support the changes to the encoding model.
+    """
+
+    def __init__(self, defaults=None):
+        self._list = []
+        if defaults is not None:
+            if isinstance(defaults, (list, Headers)):
+                self._list.extend(defaults)
+            else:
+                self.extend(defaults)
+
+    def __getitem__(self, key, _get_mode=False):
+        if not _get_mode:
+            if isinstance(key, integer_types):
+                return self._list[key]
+            elif isinstance(key, slice):
+                return self.__class__(self._list[key])
+        if not isinstance(key, string_types):
+            raise exceptions.BadRequestKeyError(key)
+        ikey = key.lower()
+        for k, v in self._list:
+            if k.lower() == ikey:
+                return v
+        # micro optimization: if we are in get mode we will catch that
+        # exception one stack level down so we can raise a standard
+        # key error instead of our special one.
+        if _get_mode:
+            raise KeyError()
+        raise exceptions.BadRequestKeyError(key)
+
+    def __eq__(self, other):
+        return other.__class__ is self.__class__ and set(other._list) == set(self._list)
+
+    __hash__ = None
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def get(self, key, default=None, type=None, as_bytes=False):
+        """Return the default value if the requested data doesn't exist.
+        If `type` is provided and is a callable it should convert the value,
+        return it or raise a :exc:`ValueError` if that is not possible.  In
+        this case the function will return the default as if the value was not
+        found:
+
+        >>> d = Headers([('Content-Length', '42')])
+        >>> d.get('Content-Length', type=int)
+        42
+
+        If a headers object is bound you must not add unicode strings
+        because no encoding takes place.
+
+        .. versionadded:: 0.9
+           Added support for `as_bytes`.
+
+        :param key: The key to be looked up.
+        :param default: The default value to be returned if the key can't
+                        be looked up.  If not further specified `None` is
+                        returned.
+        :param type: A callable that is used to cast the value in the
+                     :class:`Headers`.  If a :exc:`ValueError` is raised
+                     by this callable the default value is returned.
+        :param as_bytes: return bytes instead of unicode strings.
+        """
+        try:
+            rv = self.__getitem__(key, _get_mode=True)
+        except KeyError:
+            return default
+        if as_bytes:
+            rv = rv.encode("latin1")
+        if type is None:
+            return rv
+        try:
+            return type(rv)
+        except ValueError:
+            return default
+
+    def getlist(self, key, type=None, as_bytes=False):
+        """Return the list of items for a given key. If that key is not in the
+        :class:`Headers`, the return value will be an empty list.  Just as
+        :meth:`get` :meth:`getlist` accepts a `type` parameter.  All items will
+        be converted with the callable defined there.
+
+        .. versionadded:: 0.9
+           Added support for `as_bytes`.
+
+        :param key: The key to be looked up.
+        :param type: A callable that is used to cast the value in the
+                     :class:`Headers`.  If a :exc:`ValueError` is raised
+                     by this callable the value will be removed from the list.
+        :return: a :class:`list` of all the values for the key.
+        :param as_bytes: return bytes instead of unicode strings.
+        """
+        ikey = key.lower()
+        result = []
+        for k, v in self:
+            if k.lower() == ikey:
+                if as_bytes:
+                    v = v.encode("latin1")
+                if type is not None:
+                    try:
+                        v = type(v)
+                    except ValueError:
+                        continue
+                result.append(v)
+        return result
+
+    def get_all(self, name):
+        """Return a list of all the values for the named field.
+
+        This method is compatible with the :mod:`wsgiref`
+        :meth:`~wsgiref.headers.Headers.get_all` method.
+        """
+        return self.getlist(name)
+
+    def items(self, lower=False):
+        for key, value in self:
+            if lower:
+                key = key.lower()
+            yield key, value
+
+    def keys(self, lower=False):
+        for key, _ in iteritems(self, lower):
+            yield key
+
+    def values(self):
+        for _, value in iteritems(self):
+            yield value
+
+    def extend(self, iterable):
+        """Extend the headers with a dict or an iterable yielding keys and
+        values.
+        """
+        if isinstance(iterable, dict):
+            for key, value in iteritems(iterable):
+                if isinstance(value, (tuple, list)):
+                    for v in value:
+                        self.add(key, v)
+                else:
+                    self.add(key, value)
+        else:
+            for key, value in iterable:
+                self.add(key, value)
+
+    def __delitem__(self, key, _index_operation=True):
+        if _index_operation and isinstance(key, (integer_types, slice)):
+            del self._list[key]
+            return
+        key = key.lower()
+        new = []
+        for k, v in self._list:
+            if k.lower() != key:
+                new.append((k, v))
+        self._list[:] = new
+
+    def remove(self, key):
+        """Remove a key.
+
+        :param key: The key to be removed.
+        """
+        return self.__delitem__(key, _index_operation=False)
+
+    def pop(self, key=None, default=_missing):
+        """Removes and returns a key or index.
+
+        :param key: The key to be popped.  If this is an integer the item at
+                    that position is removed, if it's a string the value for
+                    that key is.  If the key is omitted or `None` the last
+                    item is removed.
+        :return: an item.
+        """
+        if key is None:
+            return self._list.pop()
+        if isinstance(key, integer_types):
+            return self._list.pop(key)
+        try:
+            rv = self[key]
+            self.remove(key)
+        except KeyError:
+            if default is not _missing:
+                return default
+            raise
+        return rv
+
+    def popitem(self):
+        """Removes a key or index and returns a (key, value) item."""
+        return self.pop()
+
+    def __contains__(self, key):
+        """Check if a key is present."""
+        try:
+            self.__getitem__(key, _get_mode=True)
+        except KeyError:
+            return False
+        return True
+
+    has_key = __contains__
+
+    def __iter__(self):
+        """Yield ``(key, value)`` tuples."""
+        return iter(self._list)
+
+    def __len__(self):
+        return len(self._list)
+
+    def add(self, _key, _value, **kw):
+        """Add a new header tuple to the list.
+
+        Keyword arguments can specify additional parameters for the header
+        value, with underscores converted to dashes::
+
+        >>> d = Headers()
+        >>> d.add('Content-Type', 'text/plain')
+        >>> d.add('Content-Disposition', 'attachment', filename='foo.png')
+
+        The keyword argument dumping uses :func:`dump_options_header`
+        behind the scenes.
+
+        .. versionadded:: 0.4.1
+            keyword arguments were added for :mod:`wsgiref` compatibility.
+        """
+        if kw:
+            _value = _options_header_vkw(_value, kw)
+        _key = _unicodify_header_value(_key)
+        _value = _unicodify_header_value(_value)
+        self._validate_value(_value)
+        self._list.append((_key, _value))
+
+    def _validate_value(self, value):
+        if not isinstance(value, text_type):
+            raise TypeError("Value should be unicode.")
+        if u"\n" in value or u"\r" in value:
+            raise ValueError(
+                "Detected newline in header value.  This is "
+                "a potential security problem"
+            )
+
+    def add_header(self, _key, _value, **_kw):
+        """Add a new header tuple to the list.
+
+        An alias for :meth:`add` for compatibility with the :mod:`wsgiref`
+        :meth:`~wsgiref.headers.Headers.add_header` method.
+        """
+        self.add(_key, _value, **_kw)
+
+    def clear(self):
+        """Clears all headers."""
+        del self._list[:]
+
+    def set(self, _key, _value, **kw):
+        """Remove all header tuples for `key` and add a new one.  The newly
+        added key either appears at the end of the list if there was no
+        entry or replaces the first one.
+
+        Keyword arguments can specify additional parameters for the header
+        value, with underscores converted to dashes.  See :meth:`add` for
+        more information.
+
+        .. versionchanged:: 0.6.1
+           :meth:`set` now accepts the same arguments as :meth:`add`.
+
+        :param key: The key to be inserted.
+        :param value: The value to be inserted.
+        """
+        if kw:
+            _value = _options_header_vkw(_value, kw)
+        _key = _unicodify_header_value(_key)
+        _value = _unicodify_header_value(_value)
+        self._validate_value(_value)
+        if not self._list:
+            self._list.append((_key, _value))
+            return
+        listiter = iter(self._list)
+        ikey = _key.lower()
+        for idx, (old_key, _old_value) in enumerate(listiter):
+            if old_key.lower() == ikey:
+                # replace first ocurrence
+                self._list[idx] = (_key, _value)
+                break
+        else:
+            self._list.append((_key, _value))
+            return
+        self._list[idx + 1 :] = [t for t in listiter if t[0].lower() != ikey]
+
+    def setdefault(self, key, default):
+        """Returns the value for the key if it is in the dict, otherwise it
+        returns `default` and sets that value for `key`.
+
+        :param key: The key to be looked up.
+        :param default: The default value to be returned if the key is not
+                        in the dict.  If not further specified it's `None`.
+        """
+        if key in self:
+            return self[key]
+        self.set(key, default)
+        return default
+
+    def __setitem__(self, key, value):
+        """Like :meth:`set` but also supports index/slice based setting."""
+        if isinstance(key, (slice, integer_types)):
+            if isinstance(key, integer_types):
+                value = [value]
+            value = [
+                (_unicodify_header_value(k), _unicodify_header_value(v))
+                for (k, v) in value
+            ]
+            [self._validate_value(v) for (k, v) in value]
+            if isinstance(key, integer_types):
+                self._list[key] = value[0]
+            else:
+                self._list[key] = value
+        else:
+            self.set(key, value)
+
+    def to_list(self, charset="iso-8859-1"):
+        """Convert the headers into a list suitable for WSGI.
+
+        .. deprecated:: 0.9
+        """
+        from warnings import warn
+
+        warn(
+            "'to_list' deprecated as of version 0.9 and will be removed"
+            " in version 1.0. Use 'to_wsgi_list' instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return self.to_wsgi_list()
+
+    def to_wsgi_list(self):
+        """Convert the headers into a list suitable for WSGI.
+
+        The values are byte strings in Python 2 converted to latin1 and unicode
+        strings in Python 3 for the WSGI server to encode.
+
+        :return: list
+        """
+        if PY2:
+            return [(to_native(k), v.encode("latin1")) for k, v in self]
+        return list(self)
+
+    def copy(self):
+        return self.__class__(self._list)
+
+    def __copy__(self):
+        return self.copy()
+
+    def __str__(self):
+        """Returns formatted headers suitable for HTTP transmission."""
+        strs = []
+        for key, value in self.to_wsgi_list():
+            strs.append("%s: %s" % (key, value))
+        strs.append("\r\n")
+        return "\r\n".join(strs)
+
+    def __repr__(self):
+        return "%s(%r)" % (self.__class__.__name__, list(self))
+
+
+class ImmutableHeadersMixin(object):
+    """Makes a :class:`Headers` immutable.  We do not mark them as
+    hashable though since the only usecase for this datastructure
+    in Werkzeug is a view on a mutable structure.
+
+    .. versionadded:: 0.5
+
+    :private:
+    """
+
+    def __delitem__(self, key, **kwargs):
+        is_immutable(self)
+
+    def __setitem__(self, key, value):
+        is_immutable(self)
+
+    set = __setitem__
+
+    def add(self, item):
+        is_immutable(self)
+
+    remove = add_header = add
+
+    def extend(self, iterable):
+        is_immutable(self)
+
+    def insert(self, pos, value):
+        is_immutable(self)
+
+    def pop(self, index=-1):
+        is_immutable(self)
+
+    def popitem(self):
+        is_immutable(self)
+
+    def setdefault(self, key, default):
+        is_immutable(self)
+
+
+class EnvironHeaders(ImmutableHeadersMixin, Headers):
+    """Read only version of the headers from a WSGI environment.  This
+    provides the same interface as `Headers` and is constructed from
+    a WSGI environment.
+
+    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
+    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
+    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for
+    HTTP exceptions.
+    """
+
+    def __init__(self, environ):
+        self.environ = environ
+
+    def __eq__(self, other):
+        return self.environ is other.environ
+
+    __hash__ = None
+
+    def __getitem__(self, key, _get_mode=False):
+        # _get_mode is a no-op for this class as there is no index but
+        # used because get() calls it.
+        if not isinstance(key, string_types):
+            raise KeyError(key)
+        key = key.upper().replace("-", "_")
+        if key in ("CONTENT_TYPE", "CONTENT_LENGTH"):
+            return _unicodify_header_value(self.environ[key])
+        return _unicodify_header_value(self.environ["HTTP_" + key])
+
+    def __len__(self):
+        # the iter is necessary because otherwise list calls our
+        # len which would call list again and so forth.
+        return len(list(iter(self)))
+
+    def __iter__(self):
+        for key, value in iteritems(self.environ):
+            if key.startswith("HTTP_") and key not in (
+                "HTTP_CONTENT_TYPE",
+                "HTTP_CONTENT_LENGTH",
+            ):
+                yield (
+                    key[5:].replace("_", "-").title(),
+                    _unicodify_header_value(value),
+                )
+            elif key in ("CONTENT_TYPE", "CONTENT_LENGTH") and value:
+                yield (key.replace("_", "-").title(), _unicodify_header_value(value))
+
+    def copy(self):
+        raise TypeError("cannot create %r copies" % self.__class__.__name__)
+
+
+@native_itermethods(["keys", "values", "items", "lists", "listvalues"])
+class CombinedMultiDict(ImmutableMultiDictMixin, MultiDict):
+    """A read only :class:`MultiDict` that you can pass multiple :class:`MultiDict`
+    instances as sequence and it will combine the return values of all wrapped
+    dicts:
+
+    >>> from werkzeug.datastructures import CombinedMultiDict, MultiDict
+    >>> post = MultiDict([('foo', 'bar')])
+    >>> get = MultiDict([('blub', 'blah')])
+    >>> combined = CombinedMultiDict([get, post])
+    >>> combined['foo']
+    'bar'
+    >>> combined['blub']
+    'blah'
+
+    This works for all read operations and will raise a `TypeError` for
+    methods that usually change data which isn't possible.
+
+    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
+    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
+    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for HTTP
+    exceptions.
+    """
+
+    def __reduce_ex__(self, protocol):
+        return type(self), (self.dicts,)
+
+    def __init__(self, dicts=None):
+        self.dicts = dicts or []
+
+    @classmethod
+    def fromkeys(cls):
+        raise TypeError("cannot create %r instances by fromkeys" % cls.__name__)
+
+    def __getitem__(self, key):
+        for d in self.dicts:
+            if key in d:
+                return d[key]
+        raise exceptions.BadRequestKeyError(key)
+
+    def get(self, key, default=None, type=None):
+        for d in self.dicts:
+            if key in d:
+                if type is not None:
+                    try:
+                        return type(d[key])
+                    except ValueError:
+                        continue
+                return d[key]
+        return default
+
+    def getlist(self, key, type=None):
+        rv = []
+        for d in self.dicts:
+            rv.extend(d.getlist(key, type))
+        return rv
+
+    def _keys_impl(self):
+        """This function exists so __len__ can be implemented more efficiently,
+        saving one list creation from an iterator.
+
+        Using this for Python 2's ``dict.keys`` behavior would be useless since
+        `dict.keys` in Python 2 returns a list, while we have a set here.
+        """
+        rv = set()
+        for d in self.dicts:
+            rv.update(iterkeys(d))
+        return rv
+
+    def keys(self):
+        return iter(self._keys_impl())
+
+    __iter__ = keys
+
+    def items(self, multi=False):
+        found = set()
+        for d in self.dicts:
+            for key, value in iteritems(d, multi):
+                if multi:
+                    yield key, value
+                elif key not in found:
+                    found.add(key)
+                    yield key, value
+
+    def values(self):
+        for _key, value in iteritems(self):
+            yield value
+
+    def lists(self):
+        rv = {}
+        for d in self.dicts:
+            for key, values in iterlists(d):
+                rv.setdefault(key, []).extend(values)
+        return iteritems(rv)
+
+    def listvalues(self):
+        return (x[1] for x in self.lists())
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.
+
+        This returns a :class:`MultiDict` representing the data at the
+        time of copying. The copy will no longer reflect changes to the
+        wrapped dicts.
+
+        .. versionchanged:: 0.15
+            Return a mutable :class:`MultiDict`.
+        """
+        return MultiDict(self)
+
+    def to_dict(self, flat=True):
+        """Return the contents as regular dict.  If `flat` is `True` the
+        returned dict will only have the first item present, if `flat` is
+        `False` all values will be returned as lists.
+
+        :param flat: If set to `False` the dict returned will have lists
+                     with all the values in it.  Otherwise it will only
+                     contain the first item for each key.
+        :return: a :class:`dict`
+        """
+        rv = {}
+        for d in reversed(self.dicts):
+            rv.update(d.to_dict(flat))
+        return rv
+
+    def __len__(self):
+        return len(self._keys_impl())
+
+    def __contains__(self, key):
+        for d in self.dicts:
+            if key in d:
+                return True
+        return False
+
+    has_key = __contains__
+
+    def __repr__(self):
+        return "%s(%r)" % (self.__class__.__name__, self.dicts)
+
+
+class FileMultiDict(MultiDict):
+    """A special :class:`MultiDict` that has convenience methods to add
+    files to it.  This is used for :class:`EnvironBuilder` and generally
+    useful for unittesting.
+
+    .. versionadded:: 0.5
+    """
+
+    def add_file(self, name, file, filename=None, content_type=None):
+        """Adds a new file to the dict.  `file` can be a file name or
+        a :class:`file`-like or a :class:`FileStorage` object.
+
+        :param name: the name of the field.
+        :param file: a filename or :class:`file`-like object
+        :param filename: an optional filename
+        :param content_type: an optional content type
+        """
+        if isinstance(file, FileStorage):
+            value = file
+        else:
+            if isinstance(file, string_types):
+                if filename is None:
+                    filename = file
+                file = open(file, "rb")
+            if filename and content_type is None:
+                content_type = (
+                    mimetypes.guess_type(filename)[0] or "application/octet-stream"
+                )
+            value = FileStorage(file, filename, name, content_type)
+
+        self.add(name, value)
+
+
+class ImmutableDict(ImmutableDictMixin, dict):
+    """An immutable :class:`dict`.
+
+    .. versionadded:: 0.5
+    """
+
+    def __repr__(self):
+        return "%s(%s)" % (self.__class__.__name__, dict.__repr__(self))
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return dict(self)
+
+    def __copy__(self):
+        return self
+
+
+class ImmutableMultiDict(ImmutableMultiDictMixin, MultiDict):
+    """An immutable :class:`MultiDict`.
+
+    .. versionadded:: 0.5
+    """
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return MultiDict(self)
+
+    def __copy__(self):
+        return self
+
+
+class ImmutableOrderedMultiDict(ImmutableMultiDictMixin, OrderedMultiDict):
+    """An immutable :class:`OrderedMultiDict`.
+
+    .. versionadded:: 0.6
+    """
+
+    def _iter_hashitems(self):
+        return enumerate(iteritems(self, multi=True))
+
+    def copy(self):
+        """Return a shallow mutable copy of this object.  Keep in mind that
+        the standard library's :func:`copy` function is a no-op for this class
+        like for any other python immutable type (eg: :class:`tuple`).
+        """
+        return OrderedMultiDict(self)
+
+    def __copy__(self):
+        return self
+
+
+@native_itermethods(["values"])
+class Accept(ImmutableList):
+    """An :class:`Accept` object is just a list subclass for lists of
+    ``(value, quality)`` tuples.  It is automatically sorted by specificity
+    and quality.
+
+    All :class:`Accept` objects work similar to a list but provide extra
+    functionality for working with the data.  Containment checks are
+    normalized to the rules of that header:
+
+    >>> a = CharsetAccept([('ISO-8859-1', 1), ('utf-8', 0.7)])
+    >>> a.best
+    'ISO-8859-1'
+    >>> 'iso-8859-1' in a
+    True
+    >>> 'UTF8' in a
+    True
+    >>> 'utf7' in a
+    False
+
+    To get the quality for an item you can use normal item lookup:
+
+    >>> print a['utf-8']
+    0.7
+    >>> a['utf7']
+    0
+
+    .. versionchanged:: 0.5
+       :class:`Accept` objects are forced immutable now.
+    """
+
+    def __init__(self, values=()):
+        if values is None:
+            list.__init__(self)
+            self.provided = False
+        elif isinstance(values, Accept):
+            self.provided = values.provided
+            list.__init__(self, values)
+        else:
+            self.provided = True
+            values = sorted(
+                values,
+                key=lambda x: (self._specificity(x[0]), x[1], x[0]),
+                reverse=True,
+            )
+            list.__init__(self, values)
+
+    def _specificity(self, value):
+        """Returns a tuple describing the value's specificity."""
+        return (value != "*",)
+
+    def _value_matches(self, value, item):
+        """Check if a value matches a given accept item."""
+        return item == "*" or item.lower() == value.lower()
+
+    def __getitem__(self, key):
+        """Besides index lookup (getting item n) you can also pass it a string
+        to get the quality for the item.  If the item is not in the list, the
+        returned quality is ``0``.
+        """
+        if isinstance(key, string_types):
+            return self.quality(key)
+        return list.__getitem__(self, key)
+
+    def quality(self, key):
+        """Returns the quality of the key.
+
+        .. versionadded:: 0.6
+           In previous versions you had to use the item-lookup syntax
+           (eg: ``obj[key]`` instead of ``obj.quality(key)``)
+        """
+        for item, quality in self:
+            if self._value_matches(key, item):
+                return quality
+        return 0
+
+    def __contains__(self, value):
+        for item, _quality in self:
+            if self._value_matches(value, item):
+                return True
+        return False
+
+    def __repr__(self):
+        return "%s([%s])" % (
+            self.__class__.__name__,
+            ", ".join("(%r, %s)" % (x, y) for x, y in self),
+        )
+
+    def index(self, key):
+        """Get the position of an entry or raise :exc:`ValueError`.
+
+        :param key: The key to be looked up.
+
+        .. versionchanged:: 0.5
+           This used to raise :exc:`IndexError`, which was inconsistent
+           with the list API.
+        """
+        if isinstance(key, string_types):
+            for idx, (item, _quality) in enumerate(self):
+                if self._value_matches(key, item):
+                    return idx
+            raise ValueError(key)
+        return list.index(self, key)
+
+    def find(self, key):
+        """Get the position of an entry or return -1.
+
+        :param key: The key to be looked up.
+        """
+        try:
+            return self.index(key)
+        except ValueError:
+            return -1
+
+    def values(self):
+        """Iterate over all values."""
+        for item in self:
+            yield item[0]
+
+    def to_header(self):
+        """Convert the header set into an HTTP header string."""
+        result = []
+        for value, quality in self:
+            if quality != 1:
+                value = "%s;q=%s" % (value, quality)
+            result.append(value)
+        return ",".join(result)
+
+    def __str__(self):
+        return self.to_header()
+
+    def _best_single_match(self, match):
+        for client_item, quality in self:
+            if self._value_matches(match, client_item):
+                # self is sorted by specificity descending, we can exit
+                return client_item, quality
+
+    def best_match(self, matches, default=None):
+        """Returns the best match from a list of possible matches based
+        on the specificity and quality of the client. If two items have the
+        same quality and specificity, the one is returned that comes first.
+
+        :param matches: a list of matches to check for
+        :param default: the value that is returned if none match
+        """
+        result = default
+        best_quality = -1
+        best_specificity = (-1,)
+        for server_item in matches:
+            match = self._best_single_match(server_item)
+            if not match:
+                continue
+            client_item, quality = match
+            specificity = self._specificity(client_item)
+            if quality <= 0 or quality < best_quality:
+                continue
+            # better quality or same quality but more specific => better match
+            if quality > best_quality or specificity > best_specificity:
+                result = server_item
+                best_quality = quality
+                best_specificity = specificity
+        return result
+
+    @property
+    def best(self):
+        """The best match as value."""
+        if self:
+            return self[0][0]
+
+
+class MIMEAccept(Accept):
+    """Like :class:`Accept` but with special methods and behavior for
+    mimetypes.
+    """
+
+    def _specificity(self, value):
+        return tuple(x != "*" for x in value.split("/", 1))
+
+    def _value_matches(self, value, item):
+        def _normalize(x):
+            x = x.lower()
+            return ("*", "*") if x == "*" else x.split("/", 1)
+
+        # this is from the application which is trusted.  to avoid developer
+        # frustration we actually check these for valid values
+        if "/" not in value:
+            raise ValueError("invalid mimetype %r" % value)
+        value_type, value_subtype = _normalize(value)
+        if value_type == "*" and value_subtype != "*":
+            raise ValueError("invalid mimetype %r" % value)
+
+        if "/" not in item:
+            return False
+        item_type, item_subtype = _normalize(item)
+        if item_type == "*" and item_subtype != "*":
+            return False
+        return (
+            item_type == item_subtype == "*" or value_type == value_subtype == "*"
+        ) or (
+            item_type == value_type
+            and (
+                item_subtype == "*"
+                or value_subtype == "*"
+                or item_subtype == value_subtype
+            )
+        )
+
+    @property
+    def accept_html(self):
+        """True if this object accepts HTML."""
+        return (
+            "text/html" in self or "application/xhtml+xml" in self or self.accept_xhtml
+        )
+
+    @property
+    def accept_xhtml(self):
+        """True if this object accepts XHTML."""
+        return "application/xhtml+xml" in self or "application/xml" in self
+
+    @property
+    def accept_json(self):
+        """True if this object accepts JSON."""
+        return "application/json" in self
+
+
+class LanguageAccept(Accept):
+    """Like :class:`Accept` but with normalization for languages."""
+
+    def _value_matches(self, value, item):
+        def _normalize(language):
+            return _locale_delim_re.split(language.lower())
+
+        return item == "*" or _normalize(value) == _normalize(item)
+
+
+class CharsetAccept(Accept):
+    """Like :class:`Accept` but with normalization for charsets."""
+
+    def _value_matches(self, value, item):
+        def _normalize(name):
+            try:
+                return codecs.lookup(name).name
+            except LookupError:
+                return name.lower()
+
+        return item == "*" or _normalize(value) == _normalize(item)
+
+
+def cache_property(key, empty, type):
+    """Return a new property object for a cache header.  Useful if you
+    want to add support for a cache extension in a subclass."""
+    return property(
+        lambda x: x._get_cache_value(key, empty, type),
+        lambda x, v: x._set_cache_value(key, v, type),
+        lambda x: x._del_cache_value(key),
+        "accessor for %r" % key,
+    )
+
+
+class _CacheControl(UpdateDictMixin, dict):
+    """Subclass of a dict that stores values for a Cache-Control header.  It
+    has accessors for all the cache-control directives specified in RFC 2616.
+    The class does not differentiate between request and response directives.
+
+    Because the cache-control directives in the HTTP header use dashes the
+    python descriptors use underscores for that.
+
+    To get a header of the :class:`CacheControl` object again you can convert
+    the object into a string or call the :meth:`to_header` method.  If you plan
+    to subclass it and add your own items have a look at the sourcecode for
+    that class.
+
+    .. versionchanged:: 0.4
+
+       Setting `no_cache` or `private` to boolean `True` will set the implicit
+       none-value which is ``*``:
+
+       >>> cc = ResponseCacheControl()
+       >>> cc.no_cache = True
+       >>> cc
+       <ResponseCacheControl 'no-cache'>
+       >>> cc.no_cache
+       '*'
+       >>> cc.no_cache = None
+       >>> cc
+       <ResponseCacheControl ''>
+
+       In versions before 0.5 the behavior documented here affected the now
+       no longer existing `CacheControl` class.
+    """
+
+    no_cache = cache_property("no-cache", "*", None)
+    no_store = cache_property("no-store", None, bool)
+    max_age = cache_property("max-age", -1, int)
+    no_transform = cache_property("no-transform", None, None)
+
+    def __init__(self, values=(), on_update=None):
+        dict.__init__(self, values or ())
+        self.on_update = on_update
+        self.provided = values is not None
+
+    def _get_cache_value(self, key, empty, type):
+        """Used internally by the accessor properties."""
+        if type is bool:
+            return key in self
+        if key in self:
+            value = self[key]
+            if value is None:
+                return empty
+            elif type is not None:
+                try:
+                    value = type(value)
+                except ValueError:
+                    pass
+            return value
+
+    def _set_cache_value(self, key, value, type):
+        """Used internally by the accessor properties."""
+        if type is bool:
+            if value:
+                self[key] = None
+            else:
+                self.pop(key, None)
+        else:
+            if value is None:
+                self.pop(key)
+            elif value is True:
+                self[key] = None
+            else:
+                self[key] = value
+
+    def _del_cache_value(self, key):
+        """Used internally by the accessor properties."""
+        if key in self:
+            del self[key]
+
+    def to_header(self):
+        """Convert the stored values into a cache control header."""
+        return dump_header(self)
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return "<%s %s>" % (
+            self.__class__.__name__,
+            " ".join("%s=%r" % (k, v) for k, v in sorted(self.items())),
+        )
+
+
+class RequestCacheControl(ImmutableDictMixin, _CacheControl):
+    """A cache control for requests.  This is immutable and gives access
+    to all the request-relevant cache control headers.
+
+    To get a header of the :class:`RequestCacheControl` object again you can
+    convert the object into a string or call the :meth:`to_header` method.  If
+    you plan to subclass it and add your own items have a look at the sourcecode
+    for that class.
+
+    .. versionadded:: 0.5
+       In previous versions a `CacheControl` class existed that was used
+       both for request and response.
+    """
+
+    max_stale = cache_property("max-stale", "*", int)
+    min_fresh = cache_property("min-fresh", "*", int)
+    no_transform = cache_property("no-transform", None, None)
+    only_if_cached = cache_property("only-if-cached", None, bool)
+
+
+class ResponseCacheControl(_CacheControl):
+    """A cache control for responses.  Unlike :class:`RequestCacheControl`
+    this is mutable and gives access to response-relevant cache control
+    headers.
+
+    To get a header of the :class:`ResponseCacheControl` object again you can
+    convert the object into a string or call the :meth:`to_header` method.  If
+    you plan to subclass it and add your own items have a look at the sourcecode
+    for that class.
+
+    .. versionadded:: 0.5
+       In previous versions a `CacheControl` class existed that was used
+       both for request and response.
+    """
+
+    public = cache_property("public", None, bool)
+    private = cache_property("private", "*", None)
+    must_revalidate = cache_property("must-revalidate", None, bool)
+    proxy_revalidate = cache_property("proxy-revalidate", None, bool)
+    s_maxage = cache_property("s-maxage", None, None)
+
+
+# attach cache_property to the _CacheControl as staticmethod
+# so that others can reuse it.
+_CacheControl.cache_property = staticmethod(cache_property)
+
+
+class CallbackDict(UpdateDictMixin, dict):
+    """A dict that calls a function passed every time something is changed.
+    The function is passed the dict instance.
+    """
+
+    def __init__(self, initial=None, on_update=None):
+        dict.__init__(self, initial or ())
+        self.on_update = on_update
+
+    def __repr__(self):
+        return "<%s %s>" % (self.__class__.__name__, dict.__repr__(self))
+
+
+class HeaderSet(collections_abc.MutableSet):
+    """Similar to the :class:`ETags` class this implements a set-like structure.
+    Unlike :class:`ETags` this is case insensitive and used for vary, allow, and
+    content-language headers.
+
+    If not constructed using the :func:`parse_set_header` function the
+    instantiation works like this:
+
+    >>> hs = HeaderSet(['foo', 'bar', 'baz'])
+    >>> hs
+    HeaderSet(['foo', 'bar', 'baz'])
+    """
+
+    def __init__(self, headers=None, on_update=None):
+        self._headers = list(headers or ())
+        self._set = set([x.lower() for x in self._headers])
+        self.on_update = on_update
+
+    def add(self, header):
+        """Add a new header to the set."""
+        self.update((header,))
+
+    def remove(self, header):
+        """Remove a header from the set.  This raises an :exc:`KeyError` if the
+        header is not in the set.
+
+        .. versionchanged:: 0.5
+            In older versions a :exc:`IndexError` was raised instead of a
+            :exc:`KeyError` if the object was missing.
+
+        :param header: the header to be removed.
+        """
+        key = header.lower()
+        if key not in self._set:
+            raise KeyError(header)
+        self._set.remove(key)
+        for idx, key in enumerate(self._headers):
+            if key.lower() == header:
+                del self._headers[idx]
+                break
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def update(self, iterable):
+        """Add all the headers from the iterable to the set.
+
+        :param iterable: updates the set with the items from the iterable.
+        """
+        inserted_any = False
+        for header in iterable:
+            key = header.lower()
+            if key not in self._set:
+                self._headers.append(header)
+                self._set.add(key)
+                inserted_any = True
+        if inserted_any and self.on_update is not None:
+            self.on_update(self)
+
+    def discard(self, header):
+        """Like :meth:`remove` but ignores errors.
+
+        :param header: the header to be discarded.
+        """
+        try:
+            return self.remove(header)
+        except KeyError:
+            pass
+
+    def find(self, header):
+        """Return the index of the header in the set or return -1 if not found.
+
+        :param header: the header to be looked up.
+        """
+        header = header.lower()
+        for idx, item in enumerate(self._headers):
+            if item.lower() == header:
+                return idx
+        return -1
+
+    def index(self, header):
+        """Return the index of the header in the set or raise an
+        :exc:`IndexError`.
+
+        :param header: the header to be looked up.
+        """
+        rv = self.find(header)
+        if rv < 0:
+            raise IndexError(header)
+        return rv
+
+    def clear(self):
+        """Clear the set."""
+        self._set.clear()
+        del self._headers[:]
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def as_set(self, preserve_casing=False):
+        """Return the set as real python set type.  When calling this, all
+        the items are converted to lowercase and the ordering is lost.
+
+        :param preserve_casing: if set to `True` the items in the set returned
+                                will have the original case like in the
+                                :class:`HeaderSet`, otherwise they will
+                                be lowercase.
+        """
+        if preserve_casing:
+            return set(self._headers)
+        return set(self._set)
+
+    def to_header(self):
+        """Convert the header set into an HTTP header string."""
+        return ", ".join(map(quote_header_value, self._headers))
+
+    def __getitem__(self, idx):
+        return self._headers[idx]
+
+    def __delitem__(self, idx):
+        rv = self._headers.pop(idx)
+        self._set.remove(rv.lower())
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def __setitem__(self, idx, value):
+        old = self._headers[idx]
+        self._set.remove(old.lower())
+        self._headers[idx] = value
+        self._set.add(value.lower())
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def __contains__(self, header):
+        return header.lower() in self._set
+
+    def __len__(self):
+        return len(self._set)
+
+    def __iter__(self):
+        return iter(self._headers)
+
+    def __nonzero__(self):
+        return bool(self._set)
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return "%s(%r)" % (self.__class__.__name__, self._headers)
+
+
+class ETags(collections_abc.Container, collections_abc.Iterable):
+    """A set that can be used to check if one etag is present in a collection
+    of etags.
+    """
+
+    def __init__(self, strong_etags=None, weak_etags=None, star_tag=False):
+        self._strong = frozenset(not star_tag and strong_etags or ())
+        self._weak = frozenset(weak_etags or ())
+        self.star_tag = star_tag
+
+    def as_set(self, include_weak=False):
+        """Convert the `ETags` object into a python set.  Per default all the
+        weak etags are not part of this set."""
+        rv = set(self._strong)
+        if include_weak:
+            rv.update(self._weak)
+        return rv
+
+    def is_weak(self, etag):
+        """Check if an etag is weak."""
+        return etag in self._weak
+
+    def is_strong(self, etag):
+        """Check if an etag is strong."""
+        return etag in self._strong
+
+    def contains_weak(self, etag):
+        """Check if an etag is part of the set including weak and strong tags."""
+        return self.is_weak(etag) or self.contains(etag)
+
+    def contains(self, etag):
+        """Check if an etag is part of the set ignoring weak tags.
+        It is also possible to use the ``in`` operator.
+        """
+        if self.star_tag:
+            return True
+        return self.is_strong(etag)
+
+    def contains_raw(self, etag):
+        """When passed a quoted tag it will check if this tag is part of the
+        set.  If the tag is weak it is checked against weak and strong tags,
+        otherwise strong only."""
+        etag, weak = unquote_etag(etag)
+        if weak:
+            return self.contains_weak(etag)
+        return self.contains(etag)
+
+    def to_header(self):
+        """Convert the etags set into a HTTP header string."""
+        if self.star_tag:
+            return "*"
+        return ", ".join(
+            ['"%s"' % x for x in self._strong] + ['W/"%s"' % x for x in self._weak]
+        )
+
+    def __call__(self, etag=None, data=None, include_weak=False):
+        if [etag, data].count(None) != 1:
+            raise TypeError("either tag or data required, but at least one")
+        if etag is None:
+            etag = generate_etag(data)
+        if include_weak:
+            if etag in self._weak:
+                return True
+        return etag in self._strong
+
+    def __bool__(self):
+        return bool(self.star_tag or self._strong or self._weak)
+
+    __nonzero__ = __bool__
+
+    def __str__(self):
+        return self.to_header()
+
+    def __iter__(self):
+        return iter(self._strong)
+
+    def __contains__(self, etag):
+        return self.contains(etag)
+
+    def __repr__(self):
+        return "<%s %r>" % (self.__class__.__name__, str(self))
+
+
+class IfRange(object):
+    """Very simple object that represents the `If-Range` header in parsed
+    form.  It will either have neither a etag or date or one of either but
+    never both.
+
+    .. versionadded:: 0.7
+    """
+
+    def __init__(self, etag=None, date=None):
+        #: The etag parsed and unquoted.  Ranges always operate on strong
+        #: etags so the weakness information is not necessary.
+        self.etag = etag
+        #: The date in parsed format or `None`.
+        self.date = date
+
+    def to_header(self):
+        """Converts the object back into an HTTP header."""
+        if self.date is not None:
+            return http_date(self.date)
+        if self.etag is not None:
+            return quote_etag(self.etag)
+        return ""
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return "<%s %r>" % (self.__class__.__name__, str(self))
+
+
+class Range(object):
+    """Represents a ``Range`` header. All methods only support only
+    bytes as the unit. Stores a list of ranges if given, but the methods
+    only work if only one range is provided.
+
+    :raise ValueError: If the ranges provided are invalid.
+
+    .. versionchanged:: 0.15
+        The ranges passed in are validated.
+
+    .. versionadded:: 0.7
+    """
+
+    def __init__(self, units, ranges):
+        #: The units of this range.  Usually "bytes".
+        self.units = units
+        #: A list of ``(begin, end)`` tuples for the range header provided.
+        #: The ranges are non-inclusive.
+        self.ranges = ranges
+
+        for start, end in ranges:
+            if start is None or (end is not None and (start < 0 or start >= end)):
+                raise ValueError("{} is not a valid range.".format((start, end)))
+
+    def range_for_length(self, length):
+        """If the range is for bytes, the length is not None and there is
+        exactly one range and it is satisfiable it returns a ``(start, stop)``
+        tuple, otherwise `None`.
+        """
+        if self.units != "bytes" or length is None or len(self.ranges) != 1:
+            return None
+        start, end = self.ranges[0]
+        if end is None:
+            end = length
+            if start < 0:
+                start += length
+        if is_byte_range_valid(start, end, length):
+            return start, min(end, length)
+
+    def make_content_range(self, length):
+        """Creates a :class:`~werkzeug.datastructures.ContentRange` object
+        from the current range and given content length.
+        """
+        rng = self.range_for_length(length)
+        if rng is not None:
+            return ContentRange(self.units, rng[0], rng[1], length)
+
+    def to_header(self):
+        """Converts the object back into an HTTP header."""
+        ranges = []
+        for begin, end in self.ranges:
+            if end is None:
+                ranges.append("%s-" % begin if begin >= 0 else str(begin))
+            else:
+                ranges.append("%s-%s" % (begin, end - 1))
+        return "%s=%s" % (self.units, ",".join(ranges))
+
+    def to_content_range_header(self, length):
+        """Converts the object into `Content-Range` HTTP header,
+        based on given length
+        """
+        range_for_length = self.range_for_length(length)
+        if range_for_length is not None:
+            return "%s %d-%d/%d" % (
+                self.units,
+                range_for_length[0],
+                range_for_length[1] - 1,
+                length,
+            )
+        return None
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return "<%s %r>" % (self.__class__.__name__, str(self))
+
+
+class ContentRange(object):
+    """Represents the content range header.
+
+    .. versionadded:: 0.7
+    """
+
+    def __init__(self, units, start, stop, length=None, on_update=None):
+        assert is_byte_range_valid(start, stop, length), "Bad range provided"
+        self.on_update = on_update
+        self.set(start, stop, length, units)
+
+    def _callback_property(name):  # noqa: B902
+        def fget(self):
+            return getattr(self, name)
+
+        def fset(self, value):
+            setattr(self, name, value)
+            if self.on_update is not None:
+                self.on_update(self)
+
+        return property(fget, fset)
+
+    #: The units to use, usually "bytes"
+    units = _callback_property("_units")
+    #: The start point of the range or `None`.
+    start = _callback_property("_start")
+    #: The stop point of the range (non-inclusive) or `None`.  Can only be
+    #: `None` if also start is `None`.
+    stop = _callback_property("_stop")
+    #: The length of the range or `None`.
+    length = _callback_property("_length")
+    del _callback_property
+
+    def set(self, start, stop, length=None, units="bytes"):
+        """Simple method to update the ranges."""
+        assert is_byte_range_valid(start, stop, length), "Bad range provided"
+        self._units = units
+        self._start = start
+        self._stop = stop
+        self._length = length
+        if self.on_update is not None:
+            self.on_update(self)
+
+    def unset(self):
+        """Sets the units to `None` which indicates that the header should
+        no longer be used.
+        """
+        self.set(None, None, units=None)
+
+    def to_header(self):
+        if self.units is None:
+            return ""
+        if self.length is None:
+            length = "*"
+        else:
+            length = self.length
+        if self.start is None:
+            return "%s */%s" % (self.units, length)
+        return "%s %s-%s/%s" % (self.units, self.start, self.stop - 1, length)
+
+    def __nonzero__(self):
+        return self.units is not None
+
+    __bool__ = __nonzero__
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return "<%s %r>" % (self.__class__.__name__, str(self))
+
+
+class Authorization(ImmutableDictMixin, dict):
+    """Represents an `Authorization` header sent by the client.  You should
+    not create this kind of object yourself but use it when it's returned by
+    the `parse_authorization_header` function.
+
+    This object is a dict subclass and can be altered by setting dict items
+    but it should be considered immutable as it's returned by the client and
+    not meant for modifications.
+
+    .. versionchanged:: 0.5
+       This object became immutable.
+    """
+
+    def __init__(self, auth_type, data=None):
+        dict.__init__(self, data or {})
+        self.type = auth_type
+
+    username = property(
+        lambda self: self.get("username"),
+        doc="""
+        The username transmitted.  This is set for both basic and digest
+        auth all the time.""",
+    )
+    password = property(
+        lambda self: self.get("password"),
+        doc="""
+        When the authentication type is basic this is the password
+        transmitted by the client, else `None`.""",
+    )
+    realm = property(
+        lambda self: self.get("realm"),
+        doc="""
+        This is the server realm sent back for HTTP digest auth.""",
+    )
+    nonce = property(
+        lambda self: self.get("nonce"),
+        doc="""
+        The nonce the server sent for digest auth, sent back by the client.
+        A nonce should be unique for every 401 response for HTTP digest
+        auth.""",
+    )
+    uri = property(
+        lambda self: self.get("uri"),
+        doc="""
+        The URI from Request-URI of the Request-Line; duplicated because
+        proxies are allowed to change the Request-Line in transit.  HTTP
+        digest auth only.""",
+    )
+    nc = property(
+        lambda self: self.get("nc"),
+        doc="""
+        The nonce count value transmitted by clients if a qop-header is
+        also transmitted.  HTTP digest auth only.""",
+    )
+    cnonce = property(
+        lambda self: self.get("cnonce"),
+        doc="""
+        If the server sent a qop-header in the ``WWW-Authenticate``
+        header, the client has to provide this value for HTTP digest auth.
+        See the RFC for more details.""",
+    )
+    response = property(
+        lambda self: self.get("response"),
+        doc="""
+        A string of 32 hex digits computed as defined in RFC 2617, which
+        proves that the user knows a password.  Digest auth only.""",
+    )
+    opaque = property(
+        lambda self: self.get("opaque"),
+        doc="""
+        The opaque header from the server returned unchanged by the client.
+        It is recommended that this string be base64 or hexadecimal data.
+        Digest auth only.""",
+    )
+    qop = property(
+        lambda self: self.get("qop"),
+        doc="""
+        Indicates what "quality of protection" the client has applied to
+        the message for HTTP digest auth. Note that this is a single token,
+        not a quoted list of alternatives as in WWW-Authenticate.""",
+    )
+
+
+class WWWAuthenticate(UpdateDictMixin, dict):
+    """Provides simple access to `WWW-Authenticate` headers."""
+
+    #: list of keys that require quoting in the generated header
+    _require_quoting = frozenset(["domain", "nonce", "opaque", "realm", "qop"])
+
+    def __init__(self, auth_type=None, values=None, on_update=None):
+        dict.__init__(self, values or ())
+        if auth_type:
+            self["__auth_type__"] = auth_type
+        self.on_update = on_update
+
+    def set_basic(self, realm="authentication required"):
+        """Clear the auth info and enable basic auth."""
+        dict.clear(self)
+        dict.update(self, {"__auth_type__": "basic", "realm": realm})
+        if self.on_update:
+            self.on_update(self)
+
+    def set_digest(
+        self, realm, nonce, qop=("auth",), opaque=None, algorithm=None, stale=False
+    ):
+        """Clear the auth info and enable digest auth."""
+        d = {
+            "__auth_type__": "digest",
+            "realm": realm,
+            "nonce": nonce,
+            "qop": dump_header(qop),
+        }
+        if stale:
+            d["stale"] = "TRUE"
+        if opaque is not None:
+            d["opaque"] = opaque
+        if algorithm is not None:
+            d["algorithm"] = algorithm
+        dict.clear(self)
+        dict.update(self, d)
+        if self.on_update:
+            self.on_update(self)
+
+    def to_header(self):
+        """Convert the stored values into a WWW-Authenticate header."""
+        d = dict(self)
+        auth_type = d.pop("__auth_type__", None) or "basic"
+        return "%s %s" % (
+            auth_type.title(),
+            ", ".join(
+                [
+                    "%s=%s"
+                    % (
+                        key,
+                        quote_header_value(
+                            value, allow_token=key not in self._require_quoting
+                        ),
+                    )
+                    for key, value in iteritems(d)
+                ]
+            ),
+        )
+
+    def __str__(self):
+        return self.to_header()
+
+    def __repr__(self):
+        return "<%s %r>" % (self.__class__.__name__, self.to_header())
+
+    def auth_property(name, doc=None):  # noqa: B902
+        """A static helper function for subclasses to add extra authentication
+        system properties onto a class::
+
+            class FooAuthenticate(WWWAuthenticate):
+                special_realm = auth_property('special_realm')
+
+        For more information have a look at the sourcecode to see how the
+        regular properties (:attr:`realm` etc.) are implemented.
+        """
+
+        def _set_value(self, value):
+            if value is None:
+                self.pop(name, None)
+            else:
+                self[name] = str(value)
+
+        return property(lambda x: x.get(name), _set_value, doc=doc)
+
+    def _set_property(name, doc=None):  # noqa: B902
+        def fget(self):
+            def on_update(header_set):
+                if not header_set and name in self:
+                    del self[name]
+                elif header_set:
+                    self[name] = header_set.to_header()
+
+            return parse_set_header(self.get(name), on_update)
+
+        return property(fget, doc=doc)
+
+    type = auth_property(
+        "__auth_type__",
+        doc="""The type of the auth mechanism. HTTP currently specifies
+        ``Basic`` and ``Digest``.""",
+    )
+    realm = auth_property(
+        "realm",
+        doc="""A string to be displayed to users so they know which
+        username and password to use. This string should contain at
+        least the name of the host performing the authentication and
+        might additionally indicate the collection of users who might
+        have access.""",
+    )
+    domain = _set_property(
+        "domain",
+        doc="""A list of URIs that define the protection space. If a URI
+        is an absolute path, it is relative to the canonical root URL of
+        the server being accessed.""",
+    )
+    nonce = auth_property(
+        "nonce",
+        doc="""
+        A server-specified data string which should be uniquely generated
+        each time a 401 response is made. It is recommended that this
+        string be base64 or hexadecimal data.""",
+    )
+    opaque = auth_property(
+        "opaque",
+        doc="""A string of data, specified by the server, which should
+        be returned by the client unchanged in the Authorization header
+        of subsequent requests with URIs in the same protection space.
+        It is recommended that this string be base64 or hexadecimal
+        data.""",
+    )
+    algorithm = auth_property(
+        "algorithm",
+        doc="""A string indicating a pair of algorithms used to produce
+        the digest and a checksum. If this is not present it is assumed
+        to be "MD5". If the algorithm is not understood, the challenge
+        should be ignored (and a different one used, if there is more
+        than one).""",
+    )
+    qop = _set_property(
+        "qop",
+        doc="""A set of quality-of-privacy directives such as auth and
+        auth-int.""",
+    )
+
+    @property
+    def stale(self):
+        """A flag, indicating that the previous request from the client
+        was rejected because the nonce value was stale.
+        """
+        val = self.get("stale")
+        if val is not None:
+            return val.lower() == "true"
+
+    @stale.setter
+    def stale(self, value):
+        if value is None:
+            self.pop("stale", None)
+        else:
+            self["stale"] = "TRUE" if value else "FALSE"
+
+    auth_property = staticmethod(auth_property)
+    del _set_property
+
+
+class FileStorage(object):
+    """The :class:`FileStorage` class is a thin wrapper over incoming files.
+    It is used by the request object to represent uploaded files.  All the
+    attributes of the wrapper stream are proxied by the file storage so
+    it's possible to do ``storage.read()`` instead of the long form
+    ``storage.stream.read()``.
+    """
+
+    def __init__(
+        self,
+        stream=None,
+        filename=None,
+        name=None,
+        content_type=None,
+        content_length=None,
+        headers=None,
+    ):
+        self.name = name
+        self.stream = stream or BytesIO()
+
+        # if no filename is provided we can attempt to get the filename
+        # from the stream object passed.  There we have to be careful to
+        # skip things like <fdopen>, <stderr> etc.  Python marks these
+        # special filenames with angular brackets.
+        if filename is None:
+            filename = getattr(stream, "name", None)
+            s = make_literal_wrapper(filename)
+            if filename and filename[0] == s("<") and filename[-1] == s(">"):
+                filename = None
+
+            # On Python 3 we want to make sure the filename is always unicode.
+            # This might not be if the name attribute is bytes due to the
+            # file being opened from the bytes API.
+            if not PY2 and isinstance(filename, bytes):
+                filename = filename.decode(get_filesystem_encoding(), "replace")
+
+        self.filename = filename
+        if headers is None:
+            headers = Headers()
+        self.headers = headers
+        if content_type is not None:
+            headers["Content-Type"] = content_type
+        if content_length is not None:
+            headers["Content-Length"] = str(content_length)
+
+    def _parse_content_type(self):
+        if not hasattr(self, "_parsed_content_type"):
+            self._parsed_content_type = parse_options_header(self.content_type)
+
+    @property
+    def content_type(self):
+        """The content-type sent in the header.  Usually not available"""
+        return self.headers.get("content-type")
+
+    @property
+    def content_length(self):
+        """The content-length sent in the header.  Usually not available"""
+        return int(self.headers.get("content-length") or 0)
+
+    @property
+    def mimetype(self):
+        """Like :attr:`content_type`, but without parameters (eg, without
+        charset, type etc.) and always lowercase.  For example if the content
+        type is ``text/HTML; charset=utf-8`` the mimetype would be
+        ``'text/html'``.
+
+        .. versionadded:: 0.7
+        """
+        self._parse_content_type()
+        return self._parsed_content_type[0].lower()
+
+    @property
+    def mimetype_params(self):
+        """The mimetype parameters as dict.  For example if the content
+        type is ``text/html; charset=utf-8`` the params would be
+        ``{'charset': 'utf-8'}``.
+
+        .. versionadded:: 0.7
+        """
+        self._parse_content_type()
+        return self._parsed_content_type[1]
+
+    def save(self, dst, buffer_size=16384):
+        """Save the file to a destination path or file object.  If the
+        destination is a file object you have to close it yourself after the
+        call.  The buffer size is the number of bytes held in memory during
+        the copy process.  It defaults to 16KB.
+
+        For secure file saving also have a look at :func:`secure_filename`.
+
+        :param dst: a filename or open file object the uploaded file
+                    is saved to.
+        :param buffer_size: the size of the buffer.  This works the same as
+                            the `length` parameter of
+                            :func:`shutil.copyfileobj`.
+        """
+        from shutil import copyfileobj
+
+        close_dst = False
+        if isinstance(dst, string_types):
+            dst = open(dst, "wb")
+            close_dst = True
+        try:
+            copyfileobj(self.stream, dst, buffer_size)
+        finally:
+            if close_dst:
+                dst.close()
+
+    def close(self):
+        """Close the underlying file if possible."""
+        try:
+            self.stream.close()
+        except Exception:
+            pass
+
+    def __nonzero__(self):
+        return bool(self.filename)
+
+    __bool__ = __nonzero__
+
+    def __getattr__(self, name):
+        try:
+            return getattr(self.stream, name)
+        except AttributeError:
+            # SpooledTemporaryFile doesn't implement IOBase, get the
+            # attribute from its backing file instead.
+            # https://github.com/python/cpython/pull/3249
+            if hasattr(self.stream, "_file"):
+                return getattr(self.stream._file, name)
+            raise
+
+    def __iter__(self):
+        return iter(self.stream)
+
+    def __repr__(self):
+        return "<%s: %r (%r)>" % (
+            self.__class__.__name__,
+            self.filename,
+            self.content_type,
+        )
+
+
+# circular dependencies
+from . import exceptions
+from .http import dump_header
+from .http import dump_options_header
+from .http import generate_etag
+from .http import http_date
+from .http import is_byte_range_valid
+from .http import parse_options_header
+from .http import parse_set_header
+from .http import quote_etag
+from .http import quote_header_value
+from .http import unquote_etag
diff --git a/python/werkzeug/exceptions.py b/python/werkzeug/exceptions.py
new file mode 100644
index 0000000..fb6528d
--- /dev/null
+++ b/python/werkzeug/exceptions.py
@@ -0,0 +1,774 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.exceptions
+    ~~~~~~~~~~~~~~~~~~~
+
+    This module implements a number of Python exceptions you can raise from
+    within your views to trigger a standard non-200 response.
+
+
+    Usage Example
+    -------------
+
+    ::
+
+        from werkzeug.wrappers import BaseRequest
+        from werkzeug.wsgi import responder
+        from werkzeug.exceptions import HTTPException, NotFound
+
+        def view(request):
+            raise NotFound()
+
+        @responder
+        def application(environ, start_response):
+            request = BaseRequest(environ)
+            try:
+                return view(request)
+            except HTTPException as e:
+                return e
+
+
+    As you can see from this example those exceptions are callable WSGI
+    applications.  Because of Python 2.4 compatibility those do not extend
+    from the response objects but only from the python exception class.
+
+    As a matter of fact they are not Werkzeug response objects.  However you
+    can get a response object by calling ``get_response()`` on a HTTP
+    exception.
+
+    Keep in mind that you have to pass an environment to ``get_response()``
+    because some errors fetch additional information from the WSGI
+    environment.
+
+    If you want to hook in a different exception page to say, a 404 status
+    code, you can add a second except for a specific subclass of an error::
+
+        @responder
+        def application(environ, start_response):
+            request = BaseRequest(environ)
+            try:
+                return view(request)
+            except NotFound, e:
+                return not_found(request)
+            except HTTPException, e:
+                return e
+
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import sys
+
+import werkzeug
+
+# Because of bootstrapping reasons we need to manually patch ourselves
+# onto our parent module.
+werkzeug.exceptions = sys.modules[__name__]
+
+from ._compat import implements_to_string
+from ._compat import integer_types
+from ._compat import iteritems
+from ._compat import text_type
+from ._internal import _get_environ
+from .wrappers import Response
+
+
+@implements_to_string
+class HTTPException(Exception):
+    """Baseclass for all HTTP exceptions.  This exception can be called as WSGI
+    application to render a default error page or you can catch the subclasses
+    of it independently and render nicer error messages.
+    """
+
+    code = None
+    description = None
+
+    def __init__(self, description=None, response=None):
+        super(Exception, self).__init__()
+        if description is not None:
+            self.description = description
+        self.response = response
+
+    @classmethod
+    def wrap(cls, exception, name=None):
+        """Create an exception that is a subclass of the calling HTTP
+        exception and the ``exception`` argument.
+
+        The first argument to the class will be passed to the
+        wrapped ``exception``, the rest to the HTTP exception. If
+        ``self.args`` is not empty, the wrapped exception message is
+        added to the HTTP exception description.
+
+        .. versionchanged:: 0.15
+            The description includes the wrapped exception message.
+        """
+
+        class newcls(cls, exception):
+            def __init__(self, arg=None, *args, **kwargs):
+                super(cls, self).__init__(*args, **kwargs)
+
+                if arg is None:
+                    exception.__init__(self)
+                else:
+                    exception.__init__(self, arg)
+
+            def get_description(self, environ=None):
+                out = super(cls, self).get_description(environ=environ)
+
+                if self.args:
+                    out += "<p><pre><code>{}: {}</code></pre></p>".format(
+                        exception.__name__, escape(exception.__str__(self))
+                    )
+
+                return out
+
+        newcls.__module__ = sys._getframe(1).f_globals.get("__name__")
+        newcls.__name__ = name or cls.__name__ + exception.__name__
+        return newcls
+
+    @property
+    def name(self):
+        """The status name."""
+        return HTTP_STATUS_CODES.get(self.code, "Unknown Error")
+
+    def get_description(self, environ=None):
+        """Get the description."""
+        return u"<p>%s</p>" % escape(self.description)
+
+    def get_body(self, environ=None):
+        """Get the HTML body."""
+        return text_type(
+            (
+                u'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">\n'
+                u"<title>%(code)s %(name)s</title>\n"
+                u"<h1>%(name)s</h1>\n"
+                u"%(description)s\n"
+            )
+            % {
+                "code": self.code,
+                "name": escape(self.name),
+                "description": self.get_description(environ),
+            }
+        )
+
+    def get_headers(self, environ=None):
+        """Get a list of headers."""
+        return [("Content-Type", "text/html")]
+
+    def get_response(self, environ=None):
+        """Get a response object.  If one was passed to the exception
+        it's returned directly.
+
+        :param environ: the optional environ for the request.  This
+                        can be used to modify the response depending
+                        on how the request looked like.
+        :return: a :class:`Response` object or a subclass thereof.
+        """
+        if self.response is not None:
+            return self.response
+        if environ is not None:
+            environ = _get_environ(environ)
+        headers = self.get_headers(environ)
+        return Response(self.get_body(environ), self.code, headers)
+
+    def __call__(self, environ, start_response):
+        """Call the exception as WSGI application.
+
+        :param environ: the WSGI environment.
+        :param start_response: the response callable provided by the WSGI
+                               server.
+        """
+        response = self.get_response(environ)
+        return response(environ, start_response)
+
+    def __str__(self):
+        code = self.code if self.code is not None else "???"
+        return "%s %s: %s" % (code, self.name, self.description)
+
+    def __repr__(self):
+        code = self.code if self.code is not None else "???"
+        return "<%s '%s: %s'>" % (self.__class__.__name__, code, self.name)
+
+
+class BadRequest(HTTPException):
+    """*400* `Bad Request`
+
+    Raise if the browser sends something to the application the application
+    or server cannot handle.
+    """
+
+    code = 400
+    description = (
+        "The browser (or proxy) sent a request that this server could "
+        "not understand."
+    )
+
+
+class ClientDisconnected(BadRequest):
+    """Internal exception that is raised if Werkzeug detects a disconnected
+    client.  Since the client is already gone at that point attempting to
+    send the error message to the client might not work and might ultimately
+    result in another exception in the server.  Mainly this is here so that
+    it is silenced by default as far as Werkzeug is concerned.
+
+    Since disconnections cannot be reliably detected and are unspecified
+    by WSGI to a large extent this might or might not be raised if a client
+    is gone.
+
+    .. versionadded:: 0.8
+    """
+
+
+class SecurityError(BadRequest):
+    """Raised if something triggers a security error.  This is otherwise
+    exactly like a bad request error.
+
+    .. versionadded:: 0.9
+    """
+
+
+class BadHost(BadRequest):
+    """Raised if the submitted host is badly formatted.
+
+    .. versionadded:: 0.11.2
+    """
+
+
+class Unauthorized(HTTPException):
+    """*401* ``Unauthorized``
+
+    Raise if the user is not authorized to access a resource.
+
+    The ``www_authenticate`` argument should be used to set the
+    ``WWW-Authenticate`` header. This is used for HTTP basic auth and
+    other schemes. Use :class:`~werkzeug.datastructures.WWWAuthenticate`
+    to create correctly formatted values. Strictly speaking a 401
+    response is invalid if it doesn't provide at least one value for
+    this header, although real clients typically don't care.
+
+    :param description: Override the default message used for the body
+        of the response.
+    :param www-authenticate: A single value, or list of values, for the
+        WWW-Authenticate header.
+
+    .. versionchanged:: 0.15.3
+        If the ``www_authenticate`` argument is not set, the
+        ``WWW-Authenticate`` header is not set.
+
+    .. versionchanged:: 0.15.3
+        The ``response`` argument was restored.
+
+    .. versionchanged:: 0.15.1
+        ``description`` was moved back as the first argument, restoring
+         its previous position.
+
+    .. versionchanged:: 0.15.0
+        ``www_authenticate`` was added as the first argument, ahead of
+        ``description``.
+    """
+
+    code = 401
+    description = (
+        "The server could not verify that you are authorized to access"
+        " the URL requested. You either supplied the wrong credentials"
+        " (e.g. a bad password), or your browser doesn't understand"
+        " how to supply the credentials required."
+    )
+
+    def __init__(self, description=None, response=None, www_authenticate=None):
+        HTTPException.__init__(self, description, response)
+
+        if www_authenticate is not None:
+            if not isinstance(www_authenticate, (tuple, list)):
+                www_authenticate = (www_authenticate,)
+
+        self.www_authenticate = www_authenticate
+
+    def get_headers(self, environ=None):
+        headers = HTTPException.get_headers(self, environ)
+        if self.www_authenticate:
+            headers.append(
+                ("WWW-Authenticate", ", ".join([str(x) for x in self.www_authenticate]))
+            )
+        return headers
+
+
+class Forbidden(HTTPException):
+    """*403* `Forbidden`
+
+    Raise if the user doesn't have the permission for the requested resource
+    but was authenticated.
+    """
+
+    code = 403
+    description = (
+        "You don't have the permission to access the requested"
+        " resource. It is either read-protected or not readable by the"
+        " server."
+    )
+
+
+class NotFound(HTTPException):
+    """*404* `Not Found`
+
+    Raise if a resource does not exist and never existed.
+    """
+
+    code = 404
+    description = (
+        "The requested URL was not found on the server. If you entered"
+        " the URL manually please check your spelling and try again."
+    )
+
+
+class MethodNotAllowed(HTTPException):
+    """*405* `Method Not Allowed`
+
+    Raise if the server used a method the resource does not handle.  For
+    example `POST` if the resource is view only.  Especially useful for REST.
+
+    The first argument for this exception should be a list of allowed methods.
+    Strictly speaking the response would be invalid if you don't provide valid
+    methods in the header which you can do with that list.
+    """
+
+    code = 405
+    description = "The method is not allowed for the requested URL."
+
+    def __init__(self, valid_methods=None, description=None):
+        """Takes an optional list of valid http methods
+        starting with werkzeug 0.3 the list will be mandatory."""
+        HTTPException.__init__(self, description)
+        self.valid_methods = valid_methods
+
+    def get_headers(self, environ=None):
+        headers = HTTPException.get_headers(self, environ)
+        if self.valid_methods:
+            headers.append(("Allow", ", ".join(self.valid_methods)))
+        return headers
+
+
+class NotAcceptable(HTTPException):
+    """*406* `Not Acceptable`
+
+    Raise if the server can't return any content conforming to the
+    `Accept` headers of the client.
+    """
+
+    code = 406
+
+    description = (
+        "The resource identified by the request is only capable of"
+        " generating response entities which have content"
+        " characteristics not acceptable according to the accept"
+        " headers sent in the request."
+    )
+
+
+class RequestTimeout(HTTPException):
+    """*408* `Request Timeout`
+
+    Raise to signalize a timeout.
+    """
+
+    code = 408
+    description = (
+        "The server closed the network connection because the browser"
+        " didn't finish the request within the specified time."
+    )
+
+
+class Conflict(HTTPException):
+    """*409* `Conflict`
+
+    Raise to signal that a request cannot be completed because it conflicts
+    with the current state on the server.
+
+    .. versionadded:: 0.7
+    """
+
+    code = 409
+    description = (
+        "A conflict happened while processing the request. The"
+        " resource might have been modified while the request was being"
+        " processed."
+    )
+
+
+class Gone(HTTPException):
+    """*410* `Gone`
+
+    Raise if a resource existed previously and went away without new location.
+    """
+
+    code = 410
+    description = (
+        "The requested URL is no longer available on this server and"
+        " there is no forwarding address. If you followed a link from a"
+        " foreign page, please contact the author of this page."
+    )
+
+
+class LengthRequired(HTTPException):
+    """*411* `Length Required`
+
+    Raise if the browser submitted data but no ``Content-Length`` header which
+    is required for the kind of processing the server does.
+    """
+
+    code = 411
+    description = (
+        "A request with this method requires a valid <code>Content-"
+        "Length</code> header."
+    )
+
+
+class PreconditionFailed(HTTPException):
+    """*412* `Precondition Failed`
+
+    Status code used in combination with ``If-Match``, ``If-None-Match``, or
+    ``If-Unmodified-Since``.
+    """
+
+    code = 412
+    description = (
+        "The precondition on the request for the URL failed positive evaluation."
+    )
+
+
+class RequestEntityTooLarge(HTTPException):
+    """*413* `Request Entity Too Large`
+
+    The status code one should return if the data submitted exceeded a given
+    limit.
+    """
+
+    code = 413
+    description = "The data value transmitted exceeds the capacity limit."
+
+
+class RequestURITooLarge(HTTPException):
+    """*414* `Request URI Too Large`
+
+    Like *413* but for too long URLs.
+    """
+
+    code = 414
+    description = (
+        "The length of the requested URL exceeds the capacity limit for"
+        " this server. The request cannot be processed."
+    )
+
+
+class UnsupportedMediaType(HTTPException):
+    """*415* `Unsupported Media Type`
+
+    The status code returned if the server is unable to handle the media type
+    the client transmitted.
+    """
+
+    code = 415
+    description = (
+        "The server does not support the media type transmitted in the request."
+    )
+
+
+class RequestedRangeNotSatisfiable(HTTPException):
+    """*416* `Requested Range Not Satisfiable`
+
+    The client asked for an invalid part of the file.
+
+    .. versionadded:: 0.7
+    """
+
+    code = 416
+    description = "The server cannot provide the requested range."
+
+    def __init__(self, length=None, units="bytes", description=None):
+        """Takes an optional `Content-Range` header value based on ``length``
+        parameter.
+        """
+        HTTPException.__init__(self, description)
+        self.length = length
+        self.units = units
+
+    def get_headers(self, environ=None):
+        headers = HTTPException.get_headers(self, environ)
+        if self.length is not None:
+            headers.append(("Content-Range", "%s */%d" % (self.units, self.length)))
+        return headers
+
+
+class ExpectationFailed(HTTPException):
+    """*417* `Expectation Failed`
+
+    The server cannot meet the requirements of the Expect request-header.
+
+    .. versionadded:: 0.7
+    """
+
+    code = 417
+    description = "The server could not meet the requirements of the Expect header"
+
+
+class ImATeapot(HTTPException):
+    """*418* `I'm a teapot`
+
+    The server should return this if it is a teapot and someone attempted
+    to brew coffee with it.
+
+    .. versionadded:: 0.7
+    """
+
+    code = 418
+    description = "This server is a teapot, not a coffee machine"
+
+
+class UnprocessableEntity(HTTPException):
+    """*422* `Unprocessable Entity`
+
+    Used if the request is well formed, but the instructions are otherwise
+    incorrect.
+    """
+
+    code = 422
+    description = (
+        "The request was well-formed but was unable to be followed due"
+        " to semantic errors."
+    )
+
+
+class Locked(HTTPException):
+    """*423* `Locked`
+
+    Used if the resource that is being accessed is locked.
+    """
+
+    code = 423
+    description = "The resource that is being accessed is locked."
+
+
+class FailedDependency(HTTPException):
+    """*424* `Failed Dependency`
+
+    Used if the method could not be performed on the resource
+    because the requested action depended on another action and that action failed.
+    """
+
+    code = 424
+    description = (
+        "The method could not be performed on the resource because the"
+        " requested action depended on another action and that action"
+        " failed."
+    )
+
+
+class PreconditionRequired(HTTPException):
+    """*428* `Precondition Required`
+
+    The server requires this request to be conditional, typically to prevent
+    the lost update problem, which is a race condition between two or more
+    clients attempting to update a resource through PUT or DELETE. By requiring
+    each client to include a conditional header ("If-Match" or "If-Unmodified-
+    Since") with the proper value retained from a recent GET request, the
+    server ensures that each client has at least seen the previous revision of
+    the resource.
+    """
+
+    code = 428
+    description = (
+        "This request is required to be conditional; try using"
+        ' "If-Match" or "If-Unmodified-Since".'
+    )
+
+
+class TooManyRequests(HTTPException):
+    """*429* `Too Many Requests`
+
+    The server is limiting the rate at which this user receives responses, and
+    this request exceeds that rate. (The server may use any convenient method
+    to identify users and their request rates). The server may include a
+    "Retry-After" header to indicate how long the user should wait before
+    retrying.
+    """
+
+    code = 429
+    description = "This user has exceeded an allotted request count. Try again later."
+
+
+class RequestHeaderFieldsTooLarge(HTTPException):
+    """*431* `Request Header Fields Too Large`
+
+    The server refuses to process the request because the header fields are too
+    large. One or more individual fields may be too large, or the set of all
+    headers is too large.
+    """
+
+    code = 431
+    description = "One or more header fields exceeds the maximum size."
+
+
+class UnavailableForLegalReasons(HTTPException):
+    """*451* `Unavailable For Legal Reasons`
+
+    This status code indicates that the server is denying access to the
+    resource as a consequence of a legal demand.
+    """
+
+    code = 451
+    description = "Unavailable for legal reasons."
+
+
+class InternalServerError(HTTPException):
+    """*500* `Internal Server Error`
+
+    Raise if an internal server error occurred.  This is a good fallback if an
+    unknown error occurred in the dispatcher.
+    """
+
+    code = 500
+    description = (
+        "The server encountered an internal error and was unable to"
+        " complete your request. Either the server is overloaded or"
+        " there is an error in the application."
+    )
+
+
+class NotImplemented(HTTPException):
+    """*501* `Not Implemented`
+
+    Raise if the application does not support the action requested by the
+    browser.
+    """
+
+    code = 501
+    description = "The server does not support the action requested by the browser."
+
+
+class BadGateway(HTTPException):
+    """*502* `Bad Gateway`
+
+    If you do proxying in your application you should return this status code
+    if you received an invalid response from the upstream server it accessed
+    in attempting to fulfill the request.
+    """
+
+    code = 502
+    description = (
+        "The proxy server received an invalid response from an upstream server."
+    )
+
+
+class ServiceUnavailable(HTTPException):
+    """*503* `Service Unavailable`
+
+    Status code you should return if a service is temporarily unavailable.
+    """
+
+    code = 503
+    description = (
+        "The server is temporarily unable to service your request due"
+        " to maintenance downtime or capacity problems. Please try"
+        " again later."
+    )
+
+
+class GatewayTimeout(HTTPException):
+    """*504* `Gateway Timeout`
+
+    Status code you should return if a connection to an upstream server
+    times out.
+    """
+
+    code = 504
+    description = "The connection to an upstream server timed out."
+
+
+class HTTPVersionNotSupported(HTTPException):
+    """*505* `HTTP Version Not Supported`
+
+    The server does not support the HTTP protocol version used in the request.
+    """
+
+    code = 505
+    description = (
+        "The server does not support the HTTP protocol version used in the request."
+    )
+
+
+default_exceptions = {}
+__all__ = ["HTTPException"]
+
+
+def _find_exceptions():
+    for _name, obj in iteritems(globals()):
+        try:
+            is_http_exception = issubclass(obj, HTTPException)
+        except TypeError:
+            is_http_exception = False
+        if not is_http_exception or obj.code is None:
+            continue
+        __all__.append(obj.__name__)
+        old_obj = default_exceptions.get(obj.code, None)
+        if old_obj is not None and issubclass(obj, old_obj):
+            continue
+        default_exceptions[obj.code] = obj
+
+
+_find_exceptions()
+del _find_exceptions
+
+
+class Aborter(object):
+    """When passed a dict of code -> exception items it can be used as
+    callable that raises exceptions.  If the first argument to the
+    callable is an integer it will be looked up in the mapping, if it's
+    a WSGI application it will be raised in a proxy exception.
+
+    The rest of the arguments are forwarded to the exception constructor.
+    """
+
+    def __init__(self, mapping=None, extra=None):
+        if mapping is None:
+            mapping = default_exceptions
+        self.mapping = dict(mapping)
+        if extra is not None:
+            self.mapping.update(extra)
+
+    def __call__(self, code, *args, **kwargs):
+        if not args and not kwargs and not isinstance(code, integer_types):
+            raise HTTPException(response=code)
+        if code not in self.mapping:
+            raise LookupError("no exception for %r" % code)
+        raise self.mapping[code](*args, **kwargs)
+
+
+def abort(status, *args, **kwargs):
+    """Raises an :py:exc:`HTTPException` for the given status code or WSGI
+    application::
+
+        abort(404)  # 404 Not Found
+        abort(Response('Hello World'))
+
+    Can be passed a WSGI application or a status code.  If a status code is
+    given it's looked up in the list of exceptions and will raise that
+    exception, if passed a WSGI application it will wrap it in a proxy WSGI
+    exception and raise that::
+
+       abort(404)
+       abort(Response('Hello World'))
+
+    """
+    return _aborter(status, *args, **kwargs)
+
+
+_aborter = Aborter()
+
+
+#: an exception that is used internally to signal both a key error and a
+#: bad request.  Used by a lot of the datastructures.
+BadRequestKeyError = BadRequest.wrap(KeyError)
+
+# imported here because of circular dependencies of werkzeug.utils
+from .http import HTTP_STATUS_CODES
+from .utils import escape
diff --git a/python/werkzeug/filesystem.py b/python/werkzeug/filesystem.py
new file mode 100644
index 0000000..d016cae
--- /dev/null
+++ b/python/werkzeug/filesystem.py
@@ -0,0 +1,64 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.filesystem
+    ~~~~~~~~~~~~~~~~~~~
+
+    Various utilities for the local filesystem.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import codecs
+import sys
+import warnings
+
+# We do not trust traditional unixes.
+has_likely_buggy_unicode_filesystem = (
+    sys.platform.startswith("linux") or "bsd" in sys.platform
+)
+
+
+def _is_ascii_encoding(encoding):
+    """Given an encoding this figures out if the encoding is actually ASCII (which
+    is something we don't actually want in most cases). This is necessary
+    because ASCII comes under many names such as ANSI_X3.4-1968.
+    """
+    if encoding is None:
+        return False
+    try:
+        return codecs.lookup(encoding).name == "ascii"
+    except LookupError:
+        return False
+
+
+class BrokenFilesystemWarning(RuntimeWarning, UnicodeWarning):
+    """The warning used by Werkzeug to signal a broken filesystem. Will only be
+    used once per runtime."""
+
+
+_warned_about_filesystem_encoding = False
+
+
+def get_filesystem_encoding():
+    """Returns the filesystem encoding that should be used. Note that this is
+    different from the Python understanding of the filesystem encoding which
+    might be deeply flawed. Do not use this value against Python's unicode APIs
+    because it might be different. See :ref:`filesystem-encoding` for the exact
+    behavior.
+
+    The concept of a filesystem encoding in generally is not something you
+    should rely on. As such if you ever need to use this function except for
+    writing wrapper code reconsider.
+    """
+    global _warned_about_filesystem_encoding
+    rv = sys.getfilesystemencoding()
+    if has_likely_buggy_unicode_filesystem and not rv or _is_ascii_encoding(rv):
+        if not _warned_about_filesystem_encoding:
+            warnings.warn(
+                "Detected a misconfigured UNIX filesystem: Will use"
+                " UTF-8 as filesystem encoding instead of {0!r}".format(rv),
+                BrokenFilesystemWarning,
+            )
+            _warned_about_filesystem_encoding = True
+        return "utf-8"
+    return rv
diff --git a/python/werkzeug/formparser.py b/python/werkzeug/formparser.py
new file mode 100644
index 0000000..0ddc5c8
--- /dev/null
+++ b/python/werkzeug/formparser.py
@@ -0,0 +1,586 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.formparser
+    ~~~~~~~~~~~~~~~~~~~
+
+    This module implements the form parsing.  It supports url-encoded forms
+    as well as non-nested multipart uploads.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import codecs
+import re
+from functools import update_wrapper
+from itertools import chain
+from itertools import repeat
+from itertools import tee
+
+from ._compat import BytesIO
+from ._compat import text_type
+from ._compat import to_native
+from .datastructures import FileStorage
+from .datastructures import Headers
+from .datastructures import MultiDict
+from .http import parse_options_header
+from .urls import url_decode_stream
+from .wsgi import get_content_length
+from .wsgi import get_input_stream
+from .wsgi import make_line_iter
+
+# there are some platforms where SpooledTemporaryFile is not available.
+# In that case we need to provide a fallback.
+try:
+    from tempfile import SpooledTemporaryFile
+except ImportError:
+    from tempfile import TemporaryFile
+
+    SpooledTemporaryFile = None
+
+
+#: an iterator that yields empty strings
+_empty_string_iter = repeat("")
+
+#: a regular expression for multipart boundaries
+_multipart_boundary_re = re.compile("^[ -~]{0,200}[!-~]$")
+
+#: supported http encodings that are also available in python we support
+#: for multipart messages.
+_supported_multipart_encodings = frozenset(["base64", "quoted-printable"])
+
+
+def default_stream_factory(
+    total_content_length, filename, content_type, content_length=None
+):
+    """The stream factory that is used per default."""
+    max_size = 1024 * 500
+    if SpooledTemporaryFile is not None:
+        return SpooledTemporaryFile(max_size=max_size, mode="wb+")
+    if total_content_length is None or total_content_length > max_size:
+        return TemporaryFile("wb+")
+    return BytesIO()
+
+
+def parse_form_data(
+    environ,
+    stream_factory=None,
+    charset="utf-8",
+    errors="replace",
+    max_form_memory_size=None,
+    max_content_length=None,
+    cls=None,
+    silent=True,
+):
+    """Parse the form data in the environ and return it as tuple in the form
+    ``(stream, form, files)``.  You should only call this method if the
+    transport method is `POST`, `PUT`, or `PATCH`.
+
+    If the mimetype of the data transmitted is `multipart/form-data` the
+    files multidict will be filled with `FileStorage` objects.  If the
+    mimetype is unknown the input stream is wrapped and returned as first
+    argument, else the stream is empty.
+
+    This is a shortcut for the common usage of :class:`FormDataParser`.
+
+    Have a look at :ref:`dealing-with-request-data` for more details.
+
+    .. versionadded:: 0.5
+       The `max_form_memory_size`, `max_content_length` and
+       `cls` parameters were added.
+
+    .. versionadded:: 0.5.1
+       The optional `silent` flag was added.
+
+    :param environ: the WSGI environment to be used for parsing.
+    :param stream_factory: An optional callable that returns a new read and
+                           writeable file descriptor.  This callable works
+                           the same as :meth:`~BaseResponse._get_file_stream`.
+    :param charset: The character set for URL and url encoded form data.
+    :param errors: The encoding error behavior.
+    :param max_form_memory_size: the maximum number of bytes to be accepted for
+                           in-memory stored form data.  If the data
+                           exceeds the value specified an
+                           :exc:`~exceptions.RequestEntityTooLarge`
+                           exception is raised.
+    :param max_content_length: If this is provided and the transmitted data
+                               is longer than this value an
+                               :exc:`~exceptions.RequestEntityTooLarge`
+                               exception is raised.
+    :param cls: an optional dict class to use.  If this is not specified
+                       or `None` the default :class:`MultiDict` is used.
+    :param silent: If set to False parsing errors will not be caught.
+    :return: A tuple in the form ``(stream, form, files)``.
+    """
+    return FormDataParser(
+        stream_factory,
+        charset,
+        errors,
+        max_form_memory_size,
+        max_content_length,
+        cls,
+        silent,
+    ).parse_from_environ(environ)
+
+
+def exhaust_stream(f):
+    """Helper decorator for methods that exhausts the stream on return."""
+
+    def wrapper(self, stream, *args, **kwargs):
+        try:
+            return f(self, stream, *args, **kwargs)
+        finally:
+            exhaust = getattr(stream, "exhaust", None)
+            if exhaust is not None:
+                exhaust()
+            else:
+                while 1:
+                    chunk = stream.read(1024 * 64)
+                    if not chunk:
+                        break
+
+    return update_wrapper(wrapper, f)
+
+
+class FormDataParser(object):
+    """This class implements parsing of form data for Werkzeug.  By itself
+    it can parse multipart and url encoded form data.  It can be subclassed
+    and extended but for most mimetypes it is a better idea to use the
+    untouched stream and expose it as separate attributes on a request
+    object.
+
+    .. versionadded:: 0.8
+
+    :param stream_factory: An optional callable that returns a new read and
+                           writeable file descriptor.  This callable works
+                           the same as :meth:`~BaseResponse._get_file_stream`.
+    :param charset: The character set for URL and url encoded form data.
+    :param errors: The encoding error behavior.
+    :param max_form_memory_size: the maximum number of bytes to be accepted for
+                           in-memory stored form data.  If the data
+                           exceeds the value specified an
+                           :exc:`~exceptions.RequestEntityTooLarge`
+                           exception is raised.
+    :param max_content_length: If this is provided and the transmitted data
+                               is longer than this value an
+                               :exc:`~exceptions.RequestEntityTooLarge`
+                               exception is raised.
+    :param cls: an optional dict class to use.  If this is not specified
+                       or `None` the default :class:`MultiDict` is used.
+    :param silent: If set to False parsing errors will not be caught.
+    """
+
+    def __init__(
+        self,
+        stream_factory=None,
+        charset="utf-8",
+        errors="replace",
+        max_form_memory_size=None,
+        max_content_length=None,
+        cls=None,
+        silent=True,
+    ):
+        if stream_factory is None:
+            stream_factory = default_stream_factory
+        self.stream_factory = stream_factory
+        self.charset = charset
+        self.errors = errors
+        self.max_form_memory_size = max_form_memory_size
+        self.max_content_length = max_content_length
+        if cls is None:
+            cls = MultiDict
+        self.cls = cls
+        self.silent = silent
+
+    def get_parse_func(self, mimetype, options):
+        return self.parse_functions.get(mimetype)
+
+    def parse_from_environ(self, environ):
+        """Parses the information from the environment as form data.
+
+        :param environ: the WSGI environment to be used for parsing.
+        :return: A tuple in the form ``(stream, form, files)``.
+        """
+        content_type = environ.get("CONTENT_TYPE", "")
+        content_length = get_content_length(environ)
+        mimetype, options = parse_options_header(content_type)
+        return self.parse(get_input_stream(environ), mimetype, content_length, options)
+
+    def parse(self, stream, mimetype, content_length, options=None):
+        """Parses the information from the given stream, mimetype,
+        content length and mimetype parameters.
+
+        :param stream: an input stream
+        :param mimetype: the mimetype of the data
+        :param content_length: the content length of the incoming data
+        :param options: optional mimetype parameters (used for
+                        the multipart boundary for instance)
+        :return: A tuple in the form ``(stream, form, files)``.
+        """
+        if (
+            self.max_content_length is not None
+            and content_length is not None
+            and content_length > self.max_content_length
+        ):
+            raise exceptions.RequestEntityTooLarge()
+        if options is None:
+            options = {}
+
+        parse_func = self.get_parse_func(mimetype, options)
+        if parse_func is not None:
+            try:
+                return parse_func(self, stream, mimetype, content_length, options)
+            except ValueError:
+                if not self.silent:
+                    raise
+
+        return stream, self.cls(), self.cls()
+
+    @exhaust_stream
+    def _parse_multipart(self, stream, mimetype, content_length, options):
+        parser = MultiPartParser(
+            self.stream_factory,
+            self.charset,
+            self.errors,
+            max_form_memory_size=self.max_form_memory_size,
+            cls=self.cls,
+        )
+        boundary = options.get("boundary")
+        if boundary is None:
+            raise ValueError("Missing boundary")
+        if isinstance(boundary, text_type):
+            boundary = boundary.encode("ascii")
+        form, files = parser.parse(stream, boundary, content_length)
+        return stream, form, files
+
+    @exhaust_stream
+    def _parse_urlencoded(self, stream, mimetype, content_length, options):
+        if (
+            self.max_form_memory_size is not None
+            and content_length is not None
+            and content_length > self.max_form_memory_size
+        ):
+            raise exceptions.RequestEntityTooLarge()
+        form = url_decode_stream(stream, self.charset, errors=self.errors, cls=self.cls)
+        return stream, form, self.cls()
+
+    #: mapping of mimetypes to parsing functions
+    parse_functions = {
+        "multipart/form-data": _parse_multipart,
+        "application/x-www-form-urlencoded": _parse_urlencoded,
+        "application/x-url-encoded": _parse_urlencoded,
+    }
+
+
+def is_valid_multipart_boundary(boundary):
+    """Checks if the string given is a valid multipart boundary."""
+    return _multipart_boundary_re.match(boundary) is not None
+
+
+def _line_parse(line):
+    """Removes line ending characters and returns a tuple (`stripped_line`,
+    `is_terminated`).
+    """
+    if line[-2:] in ["\r\n", b"\r\n"]:
+        return line[:-2], True
+    elif line[-1:] in ["\r", "\n", b"\r", b"\n"]:
+        return line[:-1], True
+    return line, False
+
+
+def parse_multipart_headers(iterable):
+    """Parses multipart headers from an iterable that yields lines (including
+    the trailing newline symbol).  The iterable has to be newline terminated.
+
+    The iterable will stop at the line where the headers ended so it can be
+    further consumed.
+
+    :param iterable: iterable of strings that are newline terminated
+    """
+    result = []
+    for line in iterable:
+        line = to_native(line)
+        line, line_terminated = _line_parse(line)
+        if not line_terminated:
+            raise ValueError("unexpected end of line in multipart header")
+        if not line:
+            break
+        elif line[0] in " \t" and result:
+            key, value = result[-1]
+            result[-1] = (key, value + "\n " + line[1:])
+        else:
+            parts = line.split(":", 1)
+            if len(parts) == 2:
+                result.append((parts[0].strip(), parts[1].strip()))
+
+    # we link the list to the headers, no need to create a copy, the
+    # list was not shared anyways.
+    return Headers(result)
+
+
+_begin_form = "begin_form"
+_begin_file = "begin_file"
+_cont = "cont"
+_end = "end"
+
+
+class MultiPartParser(object):
+    def __init__(
+        self,
+        stream_factory=None,
+        charset="utf-8",
+        errors="replace",
+        max_form_memory_size=None,
+        cls=None,
+        buffer_size=64 * 1024,
+    ):
+        self.charset = charset
+        self.errors = errors
+        self.max_form_memory_size = max_form_memory_size
+        self.stream_factory = (
+            default_stream_factory if stream_factory is None else stream_factory
+        )
+        self.cls = MultiDict if cls is None else cls
+
+        # make sure the buffer size is divisible by four so that we can base64
+        # decode chunk by chunk
+        assert buffer_size % 4 == 0, "buffer size has to be divisible by 4"
+        # also the buffer size has to be at least 1024 bytes long or long headers
+        # will freak out the system
+        assert buffer_size >= 1024, "buffer size has to be at least 1KB"
+
+        self.buffer_size = buffer_size
+
+    def _fix_ie_filename(self, filename):
+        """Internet Explorer 6 transmits the full file name if a file is
+        uploaded.  This function strips the full path if it thinks the
+        filename is Windows-like absolute.
+        """
+        if filename[1:3] == ":\\" or filename[:2] == "\\\\":
+            return filename.split("\\")[-1]
+        return filename
+
+    def _find_terminator(self, iterator):
+        """The terminator might have some additional newlines before it.
+        There is at least one application that sends additional newlines
+        before headers (the python setuptools package).
+        """
+        for line in iterator:
+            if not line:
+                break
+            line = line.strip()
+            if line:
+                return line
+        return b""
+
+    def fail(self, message):
+        raise ValueError(message)
+
+    def get_part_encoding(self, headers):
+        transfer_encoding = headers.get("content-transfer-encoding")
+        if (
+            transfer_encoding is not None
+            and transfer_encoding in _supported_multipart_encodings
+        ):
+            return transfer_encoding
+
+    def get_part_charset(self, headers):
+        # Figure out input charset for current part
+        content_type = headers.get("content-type")
+        if content_type:
+            mimetype, ct_params = parse_options_header(content_type)
+            return ct_params.get("charset", self.charset)
+        return self.charset
+
+    def start_file_streaming(self, filename, headers, total_content_length):
+        if isinstance(filename, bytes):
+            filename = filename.decode(self.charset, self.errors)
+        filename = self._fix_ie_filename(filename)
+        content_type = headers.get("content-type")
+        try:
+            content_length = int(headers["content-length"])
+        except (KeyError, ValueError):
+            content_length = 0
+        container = self.stream_factory(
+            total_content_length=total_content_length,
+            filename=filename,
+            content_type=content_type,
+            content_length=content_length,
+        )
+        return filename, container
+
+    def in_memory_threshold_reached(self, bytes):
+        raise exceptions.RequestEntityTooLarge()
+
+    def validate_boundary(self, boundary):
+        if not boundary:
+            self.fail("Missing boundary")
+        if not is_valid_multipart_boundary(boundary):
+            self.fail("Invalid boundary: %s" % boundary)
+        if len(boundary) > self.buffer_size:  # pragma: no cover
+            # this should never happen because we check for a minimum size
+            # of 1024 and boundaries may not be longer than 200.  The only
+            # situation when this happens is for non debug builds where
+            # the assert is skipped.
+            self.fail("Boundary longer than buffer size")
+
+    def parse_lines(self, file, boundary, content_length, cap_at_buffer=True):
+        """Generate parts of
+        ``('begin_form', (headers, name))``
+        ``('begin_file', (headers, name, filename))``
+        ``('cont', bytestring)``
+        ``('end', None)``
+
+        Always obeys the grammar
+        parts = ( begin_form cont* end |
+                  begin_file cont* end )*
+        """
+        next_part = b"--" + boundary
+        last_part = next_part + b"--"
+
+        iterator = chain(
+            make_line_iter(
+                file,
+                limit=content_length,
+                buffer_size=self.buffer_size,
+                cap_at_buffer=cap_at_buffer,
+            ),
+            _empty_string_iter,
+        )
+
+        terminator = self._find_terminator(iterator)
+
+        if terminator == last_part:
+            return
+        elif terminator != next_part:
+            self.fail("Expected boundary at start of multipart data")
+
+        while terminator != last_part:
+            headers = parse_multipart_headers(iterator)
+
+            disposition = headers.get("content-disposition")
+            if disposition is None:
+                self.fail("Missing Content-Disposition header")
+            disposition, extra = parse_options_header(disposition)
+            transfer_encoding = self.get_part_encoding(headers)
+            name = extra.get("name")
+            filename = extra.get("filename")
+
+            # if no content type is given we stream into memory.  A list is
+            # used as a temporary container.
+            if filename is None:
+                yield _begin_form, (headers, name)
+
+            # otherwise we parse the rest of the headers and ask the stream
+            # factory for something we can write in.
+            else:
+                yield _begin_file, (headers, name, filename)
+
+            buf = b""
+            for line in iterator:
+                if not line:
+                    self.fail("unexpected end of stream")
+
+                if line[:2] == b"--":
+                    terminator = line.rstrip()
+                    if terminator in (next_part, last_part):
+                        break
+
+                if transfer_encoding is not None:
+                    if transfer_encoding == "base64":
+                        transfer_encoding = "base64_codec"
+                    try:
+                        line = codecs.decode(line, transfer_encoding)
+                    except Exception:
+                        self.fail("could not decode transfer encoded chunk")
+
+                # we have something in the buffer from the last iteration.
+                # this is usually a newline delimiter.
+                if buf:
+                    yield _cont, buf
+                    buf = b""
+
+                # If the line ends with windows CRLF we write everything except
+                # the last two bytes.  In all other cases however we write
+                # everything except the last byte.  If it was a newline, that's
+                # fine, otherwise it does not matter because we will write it
+                # the next iteration.  this ensures we do not write the
+                # final newline into the stream.  That way we do not have to
+                # truncate the stream.  However we do have to make sure that
+                # if something else than a newline is in there we write it
+                # out.
+                if line[-2:] == b"\r\n":
+                    buf = b"\r\n"
+                    cutoff = -2
+                else:
+                    buf = line[-1:]
+                    cutoff = -1
+                yield _cont, line[:cutoff]
+
+            else:  # pragma: no cover
+                raise ValueError("unexpected end of part")
+
+            # if we have a leftover in the buffer that is not a newline
+            # character we have to flush it, otherwise we will chop of
+            # certain values.
+            if buf not in (b"", b"\r", b"\n", b"\r\n"):
+                yield _cont, buf
+
+            yield _end, None
+
+    def parse_parts(self, file, boundary, content_length):
+        """Generate ``('file', (name, val))`` and
+        ``('form', (name, val))`` parts.
+        """
+        in_memory = 0
+
+        for ellt, ell in self.parse_lines(file, boundary, content_length):
+            if ellt == _begin_file:
+                headers, name, filename = ell
+                is_file = True
+                guard_memory = False
+                filename, container = self.start_file_streaming(
+                    filename, headers, content_length
+                )
+                _write = container.write
+
+            elif ellt == _begin_form:
+                headers, name = ell
+                is_file = False
+                container = []
+                _write = container.append
+                guard_memory = self.max_form_memory_size is not None
+
+            elif ellt == _cont:
+                _write(ell)
+                # if we write into memory and there is a memory size limit we
+                # count the number of bytes in memory and raise an exception if
+                # there is too much data in memory.
+                if guard_memory:
+                    in_memory += len(ell)
+                    if in_memory > self.max_form_memory_size:
+                        self.in_memory_threshold_reached(in_memory)
+
+            elif ellt == _end:
+                if is_file:
+                    container.seek(0)
+                    yield (
+                        "file",
+                        (name, FileStorage(container, filename, name, headers=headers)),
+                    )
+                else:
+                    part_charset = self.get_part_charset(headers)
+                    yield (
+                        "form",
+                        (name, b"".join(container).decode(part_charset, self.errors)),
+                    )
+
+    def parse(self, file, boundary, content_length):
+        formstream, filestream = tee(
+            self.parse_parts(file, boundary, content_length), 2
+        )
+        form = (p[1] for p in formstream if p[0] == "form")
+        files = (p[1] for p in filestream if p[0] == "file")
+        return self.cls(form), self.cls(files)
+
+
+from . import exceptions
diff --git a/python/werkzeug/http.py b/python/werkzeug/http.py
new file mode 100644
index 0000000..af32007
--- /dev/null
+++ b/python/werkzeug/http.py
@@ -0,0 +1,1303 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.http
+    ~~~~~~~~~~~~~
+
+    Werkzeug comes with a bunch of utilities that help Werkzeug to deal with
+    HTTP data.  Most of the classes and functions provided by this module are
+    used by the wrappers, but they are useful on their own, too, especially if
+    the response and request objects are not used.
+
+    This covers some of the more HTTP centric features of WSGI, some other
+    utilities such as cookie handling are documented in the `werkzeug.utils`
+    module.
+
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import base64
+import re
+import warnings
+from datetime import datetime
+from datetime import timedelta
+from hashlib import md5
+from time import gmtime
+from time import time
+
+from ._compat import integer_types
+from ._compat import iteritems
+from ._compat import PY2
+from ._compat import string_types
+from ._compat import text_type
+from ._compat import to_bytes
+from ._compat import to_unicode
+from ._compat import try_coerce_native
+from ._internal import _cookie_parse_impl
+from ._internal import _cookie_quote
+from ._internal import _make_cookie_domain
+
+try:
+    from email.utils import parsedate_tz
+except ImportError:
+    from email.Utils import parsedate_tz
+
+try:
+    from urllib.request import parse_http_list as _parse_list_header
+    from urllib.parse import unquote_to_bytes as _unquote
+except ImportError:
+    from urllib2 import parse_http_list as _parse_list_header
+    from urllib2 import unquote as _unquote
+
+_cookie_charset = "latin1"
+_basic_auth_charset = "utf-8"
+# for explanation of "media-range", etc. see Sections 5.3.{1,2} of RFC 7231
+_accept_re = re.compile(
+    r"""
+    (                       # media-range capturing-parenthesis
+      [^\s;,]+              # type/subtype
+      (?:[ \t]*;[ \t]*      # ";"
+        (?:                 # parameter non-capturing-parenthesis
+          [^\s;,q][^\s;,]*  # token that doesn't start with "q"
+        |                   # or
+          q[^\s;,=][^\s;,]* # token that is more than just "q"
+        )
+      )*                    # zero or more parameters
+    )                       # end of media-range
+    (?:[ \t]*;[ \t]*q=      # weight is a "q" parameter
+      (\d*(?:\.\d+)?)       # qvalue capturing-parentheses
+      [^,]*                 # "extension" accept params: who cares?
+    )?                      # accept params are optional
+    """,
+    re.VERBOSE,
+)
+_token_chars = frozenset(
+    "!#$%&'*+-.0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ^_`abcdefghijklmnopqrstuvwxyz|~"
+)
+_etag_re = re.compile(r'([Ww]/)?(?:"(.*?)"|(.*?))(?:\s*,\s*|$)')
+_unsafe_header_chars = set('()<>@,;:"/[]?={} \t')
+_option_header_piece_re = re.compile(
+    r"""
+    ;\s*,?\s*  # newlines were replaced with commas
+    (?P<key>
+        "[^"\\]*(?:\\.[^"\\]*)*"  # quoted string
+    |
+        [^\s;,=*]+  # token
+    )
+    (?:\*(?P<count>\d+))?  # *1, optional continuation index
+    \s*
+    (?:  # optionally followed by =value
+        (?:  # equals sign, possibly with encoding
+            \*\s*=\s*  # * indicates extended notation
+            (?:  # optional encoding
+                (?P<encoding>[^\s]+?)
+                '(?P<language>[^\s]*?)'
+            )?
+        |
+            =\s*  # basic notation
+        )
+        (?P<value>
+            "[^"\\]*(?:\\.[^"\\]*)*"  # quoted string
+        |
+            [^;,]+  # token
+        )?
+    )?
+    \s*
+    """,
+    flags=re.VERBOSE,
+)
+_option_header_start_mime_type = re.compile(r",\s*([^;,\s]+)([;,]\s*.+)?")
+
+_entity_headers = frozenset(
+    [
+        "allow",
+        "content-encoding",
+        "content-language",
+        "content-length",
+        "content-location",
+        "content-md5",
+        "content-range",
+        "content-type",
+        "expires",
+        "last-modified",
+    ]
+)
+_hop_by_hop_headers = frozenset(
+    [
+        "connection",
+        "keep-alive",
+        "proxy-authenticate",
+        "proxy-authorization",
+        "te",
+        "trailer",
+        "transfer-encoding",
+        "upgrade",
+    ]
+)
+
+
+HTTP_STATUS_CODES = {
+    100: "Continue",
+    101: "Switching Protocols",
+    102: "Processing",
+    200: "OK",
+    201: "Created",
+    202: "Accepted",
+    203: "Non Authoritative Information",
+    204: "No Content",
+    205: "Reset Content",
+    206: "Partial Content",
+    207: "Multi Status",
+    226: "IM Used",  # see RFC 3229
+    300: "Multiple Choices",
+    301: "Moved Permanently",
+    302: "Found",
+    303: "See Other",
+    304: "Not Modified",
+    305: "Use Proxy",
+    307: "Temporary Redirect",
+    308: "Permanent Redirect",
+    400: "Bad Request",
+    401: "Unauthorized",
+    402: "Payment Required",  # unused
+    403: "Forbidden",
+    404: "Not Found",
+    405: "Method Not Allowed",
+    406: "Not Acceptable",
+    407: "Proxy Authentication Required",
+    408: "Request Timeout",
+    409: "Conflict",
+    410: "Gone",
+    411: "Length Required",
+    412: "Precondition Failed",
+    413: "Request Entity Too Large",
+    414: "Request URI Too Long",
+    415: "Unsupported Media Type",
+    416: "Requested Range Not Satisfiable",
+    417: "Expectation Failed",
+    418: "I'm a teapot",  # see RFC 2324
+    421: "Misdirected Request",  # see RFC 7540
+    422: "Unprocessable Entity",
+    423: "Locked",
+    424: "Failed Dependency",
+    426: "Upgrade Required",
+    428: "Precondition Required",  # see RFC 6585
+    429: "Too Many Requests",
+    431: "Request Header Fields Too Large",
+    449: "Retry With",  # proprietary MS extension
+    451: "Unavailable For Legal Reasons",
+    500: "Internal Server Error",
+    501: "Not Implemented",
+    502: "Bad Gateway",
+    503: "Service Unavailable",
+    504: "Gateway Timeout",
+    505: "HTTP Version Not Supported",
+    507: "Insufficient Storage",
+    510: "Not Extended",
+}
+
+
+def wsgi_to_bytes(data):
+    """coerce wsgi unicode represented bytes to real ones"""
+    if isinstance(data, bytes):
+        return data
+    return data.encode("latin1")  # XXX: utf8 fallback?
+
+
+def bytes_to_wsgi(data):
+    assert isinstance(data, bytes), "data must be bytes"
+    if isinstance(data, str):
+        return data
+    else:
+        return data.decode("latin1")
+
+
+def quote_header_value(value, extra_chars="", allow_token=True):
+    """Quote a header value if necessary.
+
+    .. versionadded:: 0.5
+
+    :param value: the value to quote.
+    :param extra_chars: a list of extra characters to skip quoting.
+    :param allow_token: if this is enabled token values are returned
+                        unchanged.
+    """
+    if isinstance(value, bytes):
+        value = bytes_to_wsgi(value)
+    value = str(value)
+    if allow_token:
+        token_chars = _token_chars | set(extra_chars)
+        if set(value).issubset(token_chars):
+            return value
+    return '"%s"' % value.replace("\\", "\\\\").replace('"', '\\"')
+
+
+def unquote_header_value(value, is_filename=False):
+    r"""Unquotes a header value.  (Reversal of :func:`quote_header_value`).
+    This does not use the real unquoting but what browsers are actually
+    using for quoting.
+
+    .. versionadded:: 0.5
+
+    :param value: the header value to unquote.
+    """
+    if value and value[0] == value[-1] == '"':
+        # this is not the real unquoting, but fixing this so that the
+        # RFC is met will result in bugs with internet explorer and
+        # probably some other browsers as well.  IE for example is
+        # uploading files with "C:\foo\bar.txt" as filename
+        value = value[1:-1]
+
+        # if this is a filename and the starting characters look like
+        # a UNC path, then just return the value without quotes.  Using the
+        # replace sequence below on a UNC path has the effect of turning
+        # the leading double slash into a single slash and then
+        # _fix_ie_filename() doesn't work correctly.  See #458.
+        if not is_filename or value[:2] != "\\\\":
+            return value.replace("\\\\", "\\").replace('\\"', '"')
+    return value
+
+
+def dump_options_header(header, options):
+    """The reverse function to :func:`parse_options_header`.
+
+    :param header: the header to dump
+    :param options: a dict of options to append.
+    """
+    segments = []
+    if header is not None:
+        segments.append(header)
+    for key, value in iteritems(options):
+        if value is None:
+            segments.append(key)
+        else:
+            segments.append("%s=%s" % (key, quote_header_value(value)))
+    return "; ".join(segments)
+
+
+def dump_header(iterable, allow_token=True):
+    """Dump an HTTP header again.  This is the reversal of
+    :func:`parse_list_header`, :func:`parse_set_header` and
+    :func:`parse_dict_header`.  This also quotes strings that include an
+    equals sign unless you pass it as dict of key, value pairs.
+
+    >>> dump_header({'foo': 'bar baz'})
+    'foo="bar baz"'
+    >>> dump_header(('foo', 'bar baz'))
+    'foo, "bar baz"'
+
+    :param iterable: the iterable or dict of values to quote.
+    :param allow_token: if set to `False` tokens as values are disallowed.
+                        See :func:`quote_header_value` for more details.
+    """
+    if isinstance(iterable, dict):
+        items = []
+        for key, value in iteritems(iterable):
+            if value is None:
+                items.append(key)
+            else:
+                items.append(
+                    "%s=%s" % (key, quote_header_value(value, allow_token=allow_token))
+                )
+    else:
+        items = [quote_header_value(x, allow_token=allow_token) for x in iterable]
+    return ", ".join(items)
+
+
+def parse_list_header(value):
+    """Parse lists as described by RFC 2068 Section 2.
+
+    In particular, parse comma-separated lists where the elements of
+    the list may include quoted-strings.  A quoted-string could
+    contain a comma.  A non-quoted string could have quotes in the
+    middle.  Quotes are removed automatically after parsing.
+
+    It basically works like :func:`parse_set_header` just that items
+    may appear multiple times and case sensitivity is preserved.
+
+    The return value is a standard :class:`list`:
+
+    >>> parse_list_header('token, "quoted value"')
+    ['token', 'quoted value']
+
+    To create a header from the :class:`list` again, use the
+    :func:`dump_header` function.
+
+    :param value: a string with a list header.
+    :return: :class:`list`
+    """
+    result = []
+    for item in _parse_list_header(value):
+        if item[:1] == item[-1:] == '"':
+            item = unquote_header_value(item[1:-1])
+        result.append(item)
+    return result
+
+
+def parse_dict_header(value, cls=dict):
+    """Parse lists of key, value pairs as described by RFC 2068 Section 2 and
+    convert them into a python dict (or any other mapping object created from
+    the type with a dict like interface provided by the `cls` argument):
+
+    >>> d = parse_dict_header('foo="is a fish", bar="as well"')
+    >>> type(d) is dict
+    True
+    >>> sorted(d.items())
+    [('bar', 'as well'), ('foo', 'is a fish')]
+
+    If there is no value for a key it will be `None`:
+
+    >>> parse_dict_header('key_without_value')
+    {'key_without_value': None}
+
+    To create a header from the :class:`dict` again, use the
+    :func:`dump_header` function.
+
+    .. versionchanged:: 0.9
+       Added support for `cls` argument.
+
+    :param value: a string with a dict header.
+    :param cls: callable to use for storage of parsed results.
+    :return: an instance of `cls`
+    """
+    result = cls()
+    if not isinstance(value, text_type):
+        # XXX: validate
+        value = bytes_to_wsgi(value)
+    for item in _parse_list_header(value):
+        if "=" not in item:
+            result[item] = None
+            continue
+        name, value = item.split("=", 1)
+        if value[:1] == value[-1:] == '"':
+            value = unquote_header_value(value[1:-1])
+        result[name] = value
+    return result
+
+
+def parse_options_header(value, multiple=False):
+    """Parse a ``Content-Type`` like header into a tuple with the content
+    type and the options:
+
+    >>> parse_options_header('text/html; charset=utf8')
+    ('text/html', {'charset': 'utf8'})
+
+    This should not be used to parse ``Cache-Control`` like headers that use
+    a slightly different format.  For these headers use the
+    :func:`parse_dict_header` function.
+
+    .. versionchanged:: 0.15
+        :rfc:`2231` parameter continuations are handled.
+
+    .. versionadded:: 0.5
+
+    :param value: the header to parse.
+    :param multiple: Whether try to parse and return multiple MIME types
+    :return: (mimetype, options) or (mimetype, options, mimetype, options, …)
+             if multiple=True
+    """
+    if not value:
+        return "", {}
+
+    result = []
+
+    value = "," + value.replace("\n", ",")
+    while value:
+        match = _option_header_start_mime_type.match(value)
+        if not match:
+            break
+        result.append(match.group(1))  # mimetype
+        options = {}
+        # Parse options
+        rest = match.group(2)
+        continued_encoding = None
+        while rest:
+            optmatch = _option_header_piece_re.match(rest)
+            if not optmatch:
+                break
+            option, count, encoding, language, option_value = optmatch.groups()
+            # Continuations don't have to supply the encoding after the
+            # first line. If we're in a continuation, track the current
+            # encoding to use for subsequent lines. Reset it when the
+            # continuation ends.
+            if not count:
+                continued_encoding = None
+            else:
+                if not encoding:
+                    encoding = continued_encoding
+                continued_encoding = encoding
+            option = unquote_header_value(option)
+            if option_value is not None:
+                option_value = unquote_header_value(option_value, option == "filename")
+                if encoding is not None:
+                    option_value = _unquote(option_value).decode(encoding)
+            if count:
+                # Continuations append to the existing value. For
+                # simplicity, this ignores the possibility of
+                # out-of-order indices, which shouldn't happen anyway.
+                options[option] = options.get(option, "") + option_value
+            else:
+                options[option] = option_value
+            rest = rest[optmatch.end() :]
+        result.append(options)
+        if multiple is False:
+            return tuple(result)
+        value = rest
+
+    return tuple(result) if result else ("", {})
+
+
+def parse_accept_header(value, cls=None):
+    """Parses an HTTP Accept-* header.  This does not implement a complete
+    valid algorithm but one that supports at least value and quality
+    extraction.
+
+    Returns a new :class:`Accept` object (basically a list of ``(value, quality)``
+    tuples sorted by the quality with some additional accessor methods).
+
+    The second parameter can be a subclass of :class:`Accept` that is created
+    with the parsed values and returned.
+
+    :param value: the accept header string to be parsed.
+    :param cls: the wrapper class for the return value (can be
+                         :class:`Accept` or a subclass thereof)
+    :return: an instance of `cls`.
+    """
+    if cls is None:
+        cls = Accept
+
+    if not value:
+        return cls(None)
+
+    result = []
+    for match in _accept_re.finditer(value):
+        quality = match.group(2)
+        if not quality:
+            quality = 1
+        else:
+            quality = max(min(float(quality), 1), 0)
+        result.append((match.group(1), quality))
+    return cls(result)
+
+
+def parse_cache_control_header(value, on_update=None, cls=None):
+    """Parse a cache control header.  The RFC differs between response and
+    request cache control, this method does not.  It's your responsibility
+    to not use the wrong control statements.
+
+    .. versionadded:: 0.5
+       The `cls` was added.  If not specified an immutable
+       :class:`~werkzeug.datastructures.RequestCacheControl` is returned.
+
+    :param value: a cache control header to be parsed.
+    :param on_update: an optional callable that is called every time a value
+                      on the :class:`~werkzeug.datastructures.CacheControl`
+                      object is changed.
+    :param cls: the class for the returned object.  By default
+                :class:`~werkzeug.datastructures.RequestCacheControl` is used.
+    :return: a `cls` object.
+    """
+    if cls is None:
+        cls = RequestCacheControl
+    if not value:
+        return cls(None, on_update)
+    return cls(parse_dict_header(value), on_update)
+
+
+def parse_set_header(value, on_update=None):
+    """Parse a set-like header and return a
+    :class:`~werkzeug.datastructures.HeaderSet` object:
+
+    >>> hs = parse_set_header('token, "quoted value"')
+
+    The return value is an object that treats the items case-insensitively
+    and keeps the order of the items:
+
+    >>> 'TOKEN' in hs
+    True
+    >>> hs.index('quoted value')
+    1
+    >>> hs
+    HeaderSet(['token', 'quoted value'])
+
+    To create a header from the :class:`HeaderSet` again, use the
+    :func:`dump_header` function.
+
+    :param value: a set header to be parsed.
+    :param on_update: an optional callable that is called every time a
+                      value on the :class:`~werkzeug.datastructures.HeaderSet`
+                      object is changed.
+    :return: a :class:`~werkzeug.datastructures.HeaderSet`
+    """
+    if not value:
+        return HeaderSet(None, on_update)
+    return HeaderSet(parse_list_header(value), on_update)
+
+
+def parse_authorization_header(value):
+    """Parse an HTTP basic/digest authorization header transmitted by the web
+    browser.  The return value is either `None` if the header was invalid or
+    not given, otherwise an :class:`~werkzeug.datastructures.Authorization`
+    object.
+
+    :param value: the authorization header to parse.
+    :return: a :class:`~werkzeug.datastructures.Authorization` object or `None`.
+    """
+    if not value:
+        return
+    value = wsgi_to_bytes(value)
+    try:
+        auth_type, auth_info = value.split(None, 1)
+        auth_type = auth_type.lower()
+    except ValueError:
+        return
+    if auth_type == b"basic":
+        try:
+            username, password = base64.b64decode(auth_info).split(b":", 1)
+        except Exception:
+            return
+        return Authorization(
+            "basic",
+            {
+                "username": to_unicode(username, _basic_auth_charset),
+                "password": to_unicode(password, _basic_auth_charset),
+            },
+        )
+    elif auth_type == b"digest":
+        auth_map = parse_dict_header(auth_info)
+        for key in "username", "realm", "nonce", "uri", "response":
+            if key not in auth_map:
+                return
+        if "qop" in auth_map:
+            if not auth_map.get("nc") or not auth_map.get("cnonce"):
+                return
+        return Authorization("digest", auth_map)
+
+
+def parse_www_authenticate_header(value, on_update=None):
+    """Parse an HTTP WWW-Authenticate header into a
+    :class:`~werkzeug.datastructures.WWWAuthenticate` object.
+
+    :param value: a WWW-Authenticate header to parse.
+    :param on_update: an optional callable that is called every time a value
+                      on the :class:`~werkzeug.datastructures.WWWAuthenticate`
+                      object is changed.
+    :return: a :class:`~werkzeug.datastructures.WWWAuthenticate` object.
+    """
+    if not value:
+        return WWWAuthenticate(on_update=on_update)
+    try:
+        auth_type, auth_info = value.split(None, 1)
+        auth_type = auth_type.lower()
+    except (ValueError, AttributeError):
+        return WWWAuthenticate(value.strip().lower(), on_update=on_update)
+    return WWWAuthenticate(auth_type, parse_dict_header(auth_info), on_update)
+
+
+def parse_if_range_header(value):
+    """Parses an if-range header which can be an etag or a date.  Returns
+    a :class:`~werkzeug.datastructures.IfRange` object.
+
+    .. versionadded:: 0.7
+    """
+    if not value:
+        return IfRange()
+    date = parse_date(value)
+    if date is not None:
+        return IfRange(date=date)
+    # drop weakness information
+    return IfRange(unquote_etag(value)[0])
+
+
+def parse_range_header(value, make_inclusive=True):
+    """Parses a range header into a :class:`~werkzeug.datastructures.Range`
+    object.  If the header is missing or malformed `None` is returned.
+    `ranges` is a list of ``(start, stop)`` tuples where the ranges are
+    non-inclusive.
+
+    .. versionadded:: 0.7
+    """
+    if not value or "=" not in value:
+        return None
+
+    ranges = []
+    last_end = 0
+    units, rng = value.split("=", 1)
+    units = units.strip().lower()
+
+    for item in rng.split(","):
+        item = item.strip()
+        if "-" not in item:
+            return None
+        if item.startswith("-"):
+            if last_end < 0:
+                return None
+            try:
+                begin = int(item)
+            except ValueError:
+                return None
+            end = None
+            last_end = -1
+        elif "-" in item:
+            begin, end = item.split("-", 1)
+            begin = begin.strip()
+            end = end.strip()
+            if not begin.isdigit():
+                return None
+            begin = int(begin)
+            if begin < last_end or last_end < 0:
+                return None
+            if end:
+                if not end.isdigit():
+                    return None
+                end = int(end) + 1
+                if begin >= end:
+                    return None
+            else:
+                end = None
+            last_end = end
+        ranges.append((begin, end))
+
+    return Range(units, ranges)
+
+
+def parse_content_range_header(value, on_update=None):
+    """Parses a range header into a
+    :class:`~werkzeug.datastructures.ContentRange` object or `None` if
+    parsing is not possible.
+
+    .. versionadded:: 0.7
+
+    :param value: a content range header to be parsed.
+    :param on_update: an optional callable that is called every time a value
+                      on the :class:`~werkzeug.datastructures.ContentRange`
+                      object is changed.
+    """
+    if value is None:
+        return None
+    try:
+        units, rangedef = (value or "").strip().split(None, 1)
+    except ValueError:
+        return None
+
+    if "/" not in rangedef:
+        return None
+    rng, length = rangedef.split("/", 1)
+    if length == "*":
+        length = None
+    elif length.isdigit():
+        length = int(length)
+    else:
+        return None
+
+    if rng == "*":
+        return ContentRange(units, None, None, length, on_update=on_update)
+    elif "-" not in rng:
+        return None
+
+    start, stop = rng.split("-", 1)
+    try:
+        start = int(start)
+        stop = int(stop) + 1
+    except ValueError:
+        return None
+
+    if is_byte_range_valid(start, stop, length):
+        return ContentRange(units, start, stop, length, on_update=on_update)
+
+
+def quote_etag(etag, weak=False):
+    """Quote an etag.
+
+    :param etag: the etag to quote.
+    :param weak: set to `True` to tag it "weak".
+    """
+    if '"' in etag:
+        raise ValueError("invalid etag")
+    etag = '"%s"' % etag
+    if weak:
+        etag = "W/" + etag
+    return etag
+
+
+def unquote_etag(etag):
+    """Unquote a single etag:
+
+    >>> unquote_etag('W/"bar"')
+    ('bar', True)
+    >>> unquote_etag('"bar"')
+    ('bar', False)
+
+    :param etag: the etag identifier to unquote.
+    :return: a ``(etag, weak)`` tuple.
+    """
+    if not etag:
+        return None, None
+    etag = etag.strip()
+    weak = False
+    if etag.startswith(("W/", "w/")):
+        weak = True
+        etag = etag[2:]
+    if etag[:1] == etag[-1:] == '"':
+        etag = etag[1:-1]
+    return etag, weak
+
+
+def parse_etags(value):
+    """Parse an etag header.
+
+    :param value: the tag header to parse
+    :return: an :class:`~werkzeug.datastructures.ETags` object.
+    """
+    if not value:
+        return ETags()
+    strong = []
+    weak = []
+    end = len(value)
+    pos = 0
+    while pos < end:
+        match = _etag_re.match(value, pos)
+        if match is None:
+            break
+        is_weak, quoted, raw = match.groups()
+        if raw == "*":
+            return ETags(star_tag=True)
+        elif quoted:
+            raw = quoted
+        if is_weak:
+            weak.append(raw)
+        else:
+            strong.append(raw)
+        pos = match.end()
+    return ETags(strong, weak)
+
+
+def generate_etag(data):
+    """Generate an etag for some data."""
+    return md5(data).hexdigest()
+
+
+def parse_date(value):
+    """Parse one of the following date formats into a datetime object:
+
+    .. sourcecode:: text
+
+        Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123
+        Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
+        Sun Nov  6 08:49:37 1994       ; ANSI C's asctime() format
+
+    If parsing fails the return value is `None`.
+
+    :param value: a string with a supported date format.
+    :return: a :class:`datetime.datetime` object.
+    """
+    if value:
+        t = parsedate_tz(value.strip())
+        if t is not None:
+            try:
+                year = t[0]
+                # unfortunately that function does not tell us if two digit
+                # years were part of the string, or if they were prefixed
+                # with two zeroes.  So what we do is to assume that 69-99
+                # refer to 1900, and everything below to 2000
+                if year >= 0 and year <= 68:
+                    year += 2000
+                elif year >= 69 and year <= 99:
+                    year += 1900
+                return datetime(*((year,) + t[1:7])) - timedelta(seconds=t[-1] or 0)
+            except (ValueError, OverflowError):
+                return None
+
+
+def _dump_date(d, delim):
+    """Used for `http_date` and `cookie_date`."""
+    if d is None:
+        d = gmtime()
+    elif isinstance(d, datetime):
+        d = d.utctimetuple()
+    elif isinstance(d, (integer_types, float)):
+        d = gmtime(d)
+    return "%s, %02d%s%s%s%s %02d:%02d:%02d GMT" % (
+        ("Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun")[d.tm_wday],
+        d.tm_mday,
+        delim,
+        (
+            "Jan",
+            "Feb",
+            "Mar",
+            "Apr",
+            "May",
+            "Jun",
+            "Jul",
+            "Aug",
+            "Sep",
+            "Oct",
+            "Nov",
+            "Dec",
+        )[d.tm_mon - 1],
+        delim,
+        str(d.tm_year),
+        d.tm_hour,
+        d.tm_min,
+        d.tm_sec,
+    )
+
+
+def cookie_date(expires=None):
+    """Formats the time to ensure compatibility with Netscape's cookie
+    standard.
+
+    Accepts a floating point number expressed in seconds since the epoch in, a
+    datetime object or a timetuple.  All times in UTC.  The :func:`parse_date`
+    function can be used to parse such a date.
+
+    Outputs a string in the format ``Wdy, DD-Mon-YYYY HH:MM:SS GMT``.
+
+    :param expires: If provided that date is used, otherwise the current.
+    """
+    return _dump_date(expires, "-")
+
+
+def http_date(timestamp=None):
+    """Formats the time to match the RFC1123 date format.
+
+    Accepts a floating point number expressed in seconds since the epoch in, a
+    datetime object or a timetuple.  All times in UTC.  The :func:`parse_date`
+    function can be used to parse such a date.
+
+    Outputs a string in the format ``Wdy, DD Mon YYYY HH:MM:SS GMT``.
+
+    :param timestamp: If provided that date is used, otherwise the current.
+    """
+    return _dump_date(timestamp, " ")
+
+
+def parse_age(value=None):
+    """Parses a base-10 integer count of seconds into a timedelta.
+
+    If parsing fails, the return value is `None`.
+
+    :param value: a string consisting of an integer represented in base-10
+    :return: a :class:`datetime.timedelta` object or `None`.
+    """
+    if not value:
+        return None
+    try:
+        seconds = int(value)
+    except ValueError:
+        return None
+    if seconds < 0:
+        return None
+    try:
+        return timedelta(seconds=seconds)
+    except OverflowError:
+        return None
+
+
+def dump_age(age=None):
+    """Formats the duration as a base-10 integer.
+
+    :param age: should be an integer number of seconds,
+                a :class:`datetime.timedelta` object, or,
+                if the age is unknown, `None` (default).
+    """
+    if age is None:
+        return
+    if isinstance(age, timedelta):
+        # do the equivalent of Python 2.7's timedelta.total_seconds(),
+        # but disregarding fractional seconds
+        age = age.seconds + (age.days * 24 * 3600)
+
+    age = int(age)
+    if age < 0:
+        raise ValueError("age cannot be negative")
+
+    return str(age)
+
+
+def is_resource_modified(
+    environ, etag=None, data=None, last_modified=None, ignore_if_range=True
+):
+    """Convenience method for conditional requests.
+
+    :param environ: the WSGI environment of the request to be checked.
+    :param etag: the etag for the response for comparison.
+    :param data: or alternatively the data of the response to automatically
+                 generate an etag using :func:`generate_etag`.
+    :param last_modified: an optional date of the last modification.
+    :param ignore_if_range: If `False`, `If-Range` header will be taken into
+                            account.
+    :return: `True` if the resource was modified, otherwise `False`.
+    """
+    if etag is None and data is not None:
+        etag = generate_etag(data)
+    elif data is not None:
+        raise TypeError("both data and etag given")
+    if environ["REQUEST_METHOD"] not in ("GET", "HEAD"):
+        return False
+
+    unmodified = False
+    if isinstance(last_modified, string_types):
+        last_modified = parse_date(last_modified)
+
+    # ensure that microsecond is zero because the HTTP spec does not transmit
+    # that either and we might have some false positives.  See issue #39
+    if last_modified is not None:
+        last_modified = last_modified.replace(microsecond=0)
+
+    if_range = None
+    if not ignore_if_range and "HTTP_RANGE" in environ:
+        # https://tools.ietf.org/html/rfc7233#section-3.2
+        # A server MUST ignore an If-Range header field received in a request
+        # that does not contain a Range header field.
+        if_range = parse_if_range_header(environ.get("HTTP_IF_RANGE"))
+
+    if if_range is not None and if_range.date is not None:
+        modified_since = if_range.date
+    else:
+        modified_since = parse_date(environ.get("HTTP_IF_MODIFIED_SINCE"))
+
+    if modified_since and last_modified and last_modified <= modified_since:
+        unmodified = True
+
+    if etag:
+        etag, _ = unquote_etag(etag)
+        if if_range is not None and if_range.etag is not None:
+            unmodified = parse_etags(if_range.etag).contains(etag)
+        else:
+            if_none_match = parse_etags(environ.get("HTTP_IF_NONE_MATCH"))
+            if if_none_match:
+                # https://tools.ietf.org/html/rfc7232#section-3.2
+                # "A recipient MUST use the weak comparison function when comparing
+                # entity-tags for If-None-Match"
+                unmodified = if_none_match.contains_weak(etag)
+
+            # https://tools.ietf.org/html/rfc7232#section-3.1
+            # "Origin server MUST use the strong comparison function when
+            # comparing entity-tags for If-Match"
+            if_match = parse_etags(environ.get("HTTP_IF_MATCH"))
+            if if_match:
+                unmodified = not if_match.is_strong(etag)
+
+    return not unmodified
+
+
+def remove_entity_headers(headers, allowed=("expires", "content-location")):
+    """Remove all entity headers from a list or :class:`Headers` object.  This
+    operation works in-place.  `Expires` and `Content-Location` headers are
+    by default not removed.  The reason for this is :rfc:`2616` section
+    10.3.5 which specifies some entity headers that should be sent.
+
+    .. versionchanged:: 0.5
+       added `allowed` parameter.
+
+    :param headers: a list or :class:`Headers` object.
+    :param allowed: a list of headers that should still be allowed even though
+                    they are entity headers.
+    """
+    allowed = set(x.lower() for x in allowed)
+    headers[:] = [
+        (key, value)
+        for key, value in headers
+        if not is_entity_header(key) or key.lower() in allowed
+    ]
+
+
+def remove_hop_by_hop_headers(headers):
+    """Remove all HTTP/1.1 "Hop-by-Hop" headers from a list or
+    :class:`Headers` object.  This operation works in-place.
+
+    .. versionadded:: 0.5
+
+    :param headers: a list or :class:`Headers` object.
+    """
+    headers[:] = [
+        (key, value) for key, value in headers if not is_hop_by_hop_header(key)
+    ]
+
+
+def is_entity_header(header):
+    """Check if a header is an entity header.
+
+    .. versionadded:: 0.5
+
+    :param header: the header to test.
+    :return: `True` if it's an entity header, `False` otherwise.
+    """
+    return header.lower() in _entity_headers
+
+
+def is_hop_by_hop_header(header):
+    """Check if a header is an HTTP/1.1 "Hop-by-Hop" header.
+
+    .. versionadded:: 0.5
+
+    :param header: the header to test.
+    :return: `True` if it's an HTTP/1.1 "Hop-by-Hop" header, `False` otherwise.
+    """
+    return header.lower() in _hop_by_hop_headers
+
+
+def parse_cookie(header, charset="utf-8", errors="replace", cls=None):
+    """Parse a cookie.  Either from a string or WSGI environ.
+
+    Per default encoding errors are ignored.  If you want a different behavior
+    you can set `errors` to ``'replace'`` or ``'strict'``.  In strict mode a
+    :exc:`HTTPUnicodeError` is raised.
+
+    .. versionchanged:: 0.5
+       This function now returns a :class:`TypeConversionDict` instead of a
+       regular dict.  The `cls` parameter was added.
+
+    :param header: the header to be used to parse the cookie.  Alternatively
+                   this can be a WSGI environment.
+    :param charset: the charset for the cookie values.
+    :param errors: the error behavior for the charset decoding.
+    :param cls: an optional dict class to use.  If this is not specified
+                       or `None` the default :class:`TypeConversionDict` is
+                       used.
+    """
+    if isinstance(header, dict):
+        header = header.get("HTTP_COOKIE", "")
+    elif header is None:
+        header = ""
+
+    # If the value is an unicode string it's mangled through latin1.  This
+    # is done because on PEP 3333 on Python 3 all headers are assumed latin1
+    # which however is incorrect for cookies, which are sent in page encoding.
+    # As a result we
+    if isinstance(header, text_type):
+        header = header.encode("latin1", "replace")
+
+    if cls is None:
+        cls = TypeConversionDict
+
+    def _parse_pairs():
+        for key, val in _cookie_parse_impl(header):
+            key = to_unicode(key, charset, errors, allow_none_charset=True)
+            if not key:
+                continue
+            val = to_unicode(val, charset, errors, allow_none_charset=True)
+            yield try_coerce_native(key), val
+
+    return cls(_parse_pairs())
+
+
+def dump_cookie(
+    key,
+    value="",
+    max_age=None,
+    expires=None,
+    path="/",
+    domain=None,
+    secure=False,
+    httponly=False,
+    charset="utf-8",
+    sync_expires=True,
+    max_size=4093,
+    samesite=None,
+):
+    """Creates a new Set-Cookie header without the ``Set-Cookie`` prefix
+    The parameters are the same as in the cookie Morsel object in the
+    Python standard library but it accepts unicode data, too.
+
+    On Python 3 the return value of this function will be a unicode
+    string, on Python 2 it will be a native string.  In both cases the
+    return value is usually restricted to ascii as the vast majority of
+    values are properly escaped, but that is no guarantee.  If a unicode
+    string is returned it's tunneled through latin1 as required by
+    PEP 3333.
+
+    The return value is not ASCII safe if the key contains unicode
+    characters.  This is technically against the specification but
+    happens in the wild.  It's strongly recommended to not use
+    non-ASCII values for the keys.
+
+    :param max_age: should be a number of seconds, or `None` (default) if
+                    the cookie should last only as long as the client's
+                    browser session.  Additionally `timedelta` objects
+                    are accepted, too.
+    :param expires: should be a `datetime` object or unix timestamp.
+    :param path: limits the cookie to a given path, per default it will
+                 span the whole domain.
+    :param domain: Use this if you want to set a cross-domain cookie. For
+                   example, ``domain=".example.com"`` will set a cookie
+                   that is readable by the domain ``www.example.com``,
+                   ``foo.example.com`` etc. Otherwise, a cookie will only
+                   be readable by the domain that set it.
+    :param secure: The cookie will only be available via HTTPS
+    :param httponly: disallow JavaScript to access the cookie.  This is an
+                     extension to the cookie standard and probably not
+                     supported by all browsers.
+    :param charset: the encoding for unicode values.
+    :param sync_expires: automatically set expires if max_age is defined
+                         but expires not.
+    :param max_size: Warn if the final header value exceeds this size. The
+        default, 4093, should be safely `supported by most browsers
+        <cookie_>`_. Set to 0 to disable this check.
+    :param samesite: Limits the scope of the cookie such that it will only
+                     be attached to requests if those requests are "same-site".
+
+    .. _`cookie`: http://browsercookielimits.squawky.net/
+    """
+    key = to_bytes(key, charset)
+    value = to_bytes(value, charset)
+
+    if path is not None:
+        path = iri_to_uri(path, charset)
+    domain = _make_cookie_domain(domain)
+    if isinstance(max_age, timedelta):
+        max_age = (max_age.days * 60 * 60 * 24) + max_age.seconds
+    if expires is not None:
+        if not isinstance(expires, string_types):
+            expires = cookie_date(expires)
+    elif max_age is not None and sync_expires:
+        expires = to_bytes(cookie_date(time() + max_age))
+
+    samesite = samesite.title() if samesite else None
+    if samesite not in ("Strict", "Lax", None):
+        raise ValueError("invalid SameSite value; must be 'Strict', 'Lax' or None")
+
+    buf = [key + b"=" + _cookie_quote(value)]
+
+    # XXX: In theory all of these parameters that are not marked with `None`
+    # should be quoted.  Because stdlib did not quote it before I did not
+    # want to introduce quoting there now.
+    for k, v, q in (
+        (b"Domain", domain, True),
+        (b"Expires", expires, False),
+        (b"Max-Age", max_age, False),
+        (b"Secure", secure, None),
+        (b"HttpOnly", httponly, None),
+        (b"Path", path, False),
+        (b"SameSite", samesite, False),
+    ):
+        if q is None:
+            if v:
+                buf.append(k)
+            continue
+
+        if v is None:
+            continue
+
+        tmp = bytearray(k)
+        if not isinstance(v, (bytes, bytearray)):
+            v = to_bytes(text_type(v), charset)
+        if q:
+            v = _cookie_quote(v)
+        tmp += b"=" + v
+        buf.append(bytes(tmp))
+
+    # The return value will be an incorrectly encoded latin1 header on
+    # Python 3 for consistency with the headers object and a bytestring
+    # on Python 2 because that's how the API makes more sense.
+    rv = b"; ".join(buf)
+    if not PY2:
+        rv = rv.decode("latin1")
+
+    # Warn if the final value of the cookie is less than the limit. If the
+    # cookie is too large, then it may be silently ignored, which can be quite
+    # hard to debug.
+    cookie_size = len(rv)
+
+    if max_size and cookie_size > max_size:
+        value_size = len(value)
+        warnings.warn(
+            'The "{key}" cookie is too large: the value was {value_size} bytes'
+            " but the header required {extra_size} extra bytes. The final size"
+            " was {cookie_size} bytes but the limit is {max_size} bytes."
+            " Browsers may silently ignore cookies larger than this.".format(
+                key=key,
+                value_size=value_size,
+                extra_size=cookie_size - value_size,
+                cookie_size=cookie_size,
+                max_size=max_size,
+            ),
+            stacklevel=2,
+        )
+
+    return rv
+
+
+def is_byte_range_valid(start, stop, length):
+    """Checks if a given byte content range is valid for the given length.
+
+    .. versionadded:: 0.7
+    """
+    if (start is None) != (stop is None):
+        return False
+    elif start is None:
+        return length is None or length >= 0
+    elif length is None:
+        return 0 <= start < stop
+    elif start >= stop:
+        return False
+    return 0 <= start < length
+
+
+# circular dependency fun
+from .datastructures import Accept
+from .datastructures import Authorization
+from .datastructures import ContentRange
+from .datastructures import ETags
+from .datastructures import HeaderSet
+from .datastructures import IfRange
+from .datastructures import Range
+from .datastructures import RequestCacheControl
+from .datastructures import TypeConversionDict
+from .datastructures import WWWAuthenticate
+from .urls import iri_to_uri
+
+# DEPRECATED
+from .datastructures import CharsetAccept as _CharsetAccept
+from .datastructures import Headers as _Headers
+from .datastructures import LanguageAccept as _LanguageAccept
+from .datastructures import MIMEAccept as _MIMEAccept
+
+
+class MIMEAccept(_MIMEAccept):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.http.MIMEAccept' has moved to 'werkzeug"
+            ".datastructures.MIMEAccept' as of version 0.5. This old"
+            " import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(MIMEAccept, self).__init__(*args, **kwargs)
+
+
+class CharsetAccept(_CharsetAccept):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.http.CharsetAccept' has moved to 'werkzeug"
+            ".datastructures.CharsetAccept' as of version 0.5. This old"
+            " import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(CharsetAccept, self).__init__(*args, **kwargs)
+
+
+class LanguageAccept(_LanguageAccept):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.http.LanguageAccept' has moved to 'werkzeug"
+            ".datastructures.LanguageAccept' as of version 0.5. This"
+            " old import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(LanguageAccept, self).__init__(*args, **kwargs)
+
+
+class Headers(_Headers):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.http.Headers' has moved to 'werkzeug"
+            ".datastructures.Headers' as of version 0.5. This old"
+            " import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(Headers, self).__init__(*args, **kwargs)
diff --git a/python/werkzeug/local.py b/python/werkzeug/local.py
new file mode 100644
index 0000000..9a6088c
--- /dev/null
+++ b/python/werkzeug/local.py
@@ -0,0 +1,421 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.local
+    ~~~~~~~~~~~~~~
+
+    This module implements context-local objects.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import copy
+from functools import update_wrapper
+
+from ._compat import implements_bool
+from ._compat import PY2
+from .wsgi import ClosingIterator
+
+# since each thread has its own greenlet we can just use those as identifiers
+# for the context.  If greenlets are not available we fall back to the
+# current thread ident depending on where it is.
+try:
+    from greenlet import getcurrent as get_ident
+except ImportError:
+    try:
+        from thread import get_ident
+    except ImportError:
+        from _thread import get_ident
+
+
+def release_local(local):
+    """Releases the contents of the local for the current context.
+    This makes it possible to use locals without a manager.
+
+    Example::
+
+        >>> loc = Local()
+        >>> loc.foo = 42
+        >>> release_local(loc)
+        >>> hasattr(loc, 'foo')
+        False
+
+    With this function one can release :class:`Local` objects as well
+    as :class:`LocalStack` objects.  However it is not possible to
+    release data held by proxies that way, one always has to retain
+    a reference to the underlying local object in order to be able
+    to release it.
+
+    .. versionadded:: 0.6.1
+    """
+    local.__release_local__()
+
+
+class Local(object):
+    __slots__ = ("__storage__", "__ident_func__")
+
+    def __init__(self):
+        object.__setattr__(self, "__storage__", {})
+        object.__setattr__(self, "__ident_func__", get_ident)
+
+    def __iter__(self):
+        return iter(self.__storage__.items())
+
+    def __call__(self, proxy):
+        """Create a proxy for a name."""
+        return LocalProxy(self, proxy)
+
+    def __release_local__(self):
+        self.__storage__.pop(self.__ident_func__(), None)
+
+    def __getattr__(self, name):
+        try:
+            return self.__storage__[self.__ident_func__()][name]
+        except KeyError:
+            raise AttributeError(name)
+
+    def __setattr__(self, name, value):
+        ident = self.__ident_func__()
+        storage = self.__storage__
+        try:
+            storage[ident][name] = value
+        except KeyError:
+            storage[ident] = {name: value}
+
+    def __delattr__(self, name):
+        try:
+            del self.__storage__[self.__ident_func__()][name]
+        except KeyError:
+            raise AttributeError(name)
+
+
+class LocalStack(object):
+    """This class works similar to a :class:`Local` but keeps a stack
+    of objects instead.  This is best explained with an example::
+
+        >>> ls = LocalStack()
+        >>> ls.push(42)
+        >>> ls.top
+        42
+        >>> ls.push(23)
+        >>> ls.top
+        23
+        >>> ls.pop()
+        23
+        >>> ls.top
+        42
+
+    They can be force released by using a :class:`LocalManager` or with
+    the :func:`release_local` function but the correct way is to pop the
+    item from the stack after using.  When the stack is empty it will
+    no longer be bound to the current context (and as such released).
+
+    By calling the stack without arguments it returns a proxy that resolves to
+    the topmost item on the stack.
+
+    .. versionadded:: 0.6.1
+    """
+
+    def __init__(self):
+        self._local = Local()
+
+    def __release_local__(self):
+        self._local.__release_local__()
+
+    def _get__ident_func__(self):
+        return self._local.__ident_func__
+
+    def _set__ident_func__(self, value):
+        object.__setattr__(self._local, "__ident_func__", value)
+
+    __ident_func__ = property(_get__ident_func__, _set__ident_func__)
+    del _get__ident_func__, _set__ident_func__
+
+    def __call__(self):
+        def _lookup():
+            rv = self.top
+            if rv is None:
+                raise RuntimeError("object unbound")
+            return rv
+
+        return LocalProxy(_lookup)
+
+    def push(self, obj):
+        """Pushes a new item to the stack"""
+        rv = getattr(self._local, "stack", None)
+        if rv is None:
+            self._local.stack = rv = []
+        rv.append(obj)
+        return rv
+
+    def pop(self):
+        """Removes the topmost item from the stack, will return the
+        old value or `None` if the stack was already empty.
+        """
+        stack = getattr(self._local, "stack", None)
+        if stack is None:
+            return None
+        elif len(stack) == 1:
+            release_local(self._local)
+            return stack[-1]
+        else:
+            return stack.pop()
+
+    @property
+    def top(self):
+        """The topmost item on the stack.  If the stack is empty,
+        `None` is returned.
+        """
+        try:
+            return self._local.stack[-1]
+        except (AttributeError, IndexError):
+            return None
+
+
+class LocalManager(object):
+    """Local objects cannot manage themselves. For that you need a local
+    manager.  You can pass a local manager multiple locals or add them later
+    by appending them to `manager.locals`.  Every time the manager cleans up,
+    it will clean up all the data left in the locals for this context.
+
+    The `ident_func` parameter can be added to override the default ident
+    function for the wrapped locals.
+
+    .. versionchanged:: 0.6.1
+       Instead of a manager the :func:`release_local` function can be used
+       as well.
+
+    .. versionchanged:: 0.7
+       `ident_func` was added.
+    """
+
+    def __init__(self, locals=None, ident_func=None):
+        if locals is None:
+            self.locals = []
+        elif isinstance(locals, Local):
+            self.locals = [locals]
+        else:
+            self.locals = list(locals)
+        if ident_func is not None:
+            self.ident_func = ident_func
+            for local in self.locals:
+                object.__setattr__(local, "__ident_func__", ident_func)
+        else:
+            self.ident_func = get_ident
+
+    def get_ident(self):
+        """Return the context identifier the local objects use internally for
+        this context.  You cannot override this method to change the behavior
+        but use it to link other context local objects (such as SQLAlchemy's
+        scoped sessions) to the Werkzeug locals.
+
+        .. versionchanged:: 0.7
+           You can pass a different ident function to the local manager that
+           will then be propagated to all the locals passed to the
+           constructor.
+        """
+        return self.ident_func()
+
+    def cleanup(self):
+        """Manually clean up the data in the locals for this context.  Call
+        this at the end of the request or use `make_middleware()`.
+        """
+        for local in self.locals:
+            release_local(local)
+
+    def make_middleware(self, app):
+        """Wrap a WSGI application so that cleaning up happens after
+        request end.
+        """
+
+        def application(environ, start_response):
+            return ClosingIterator(app(environ, start_response), self.cleanup)
+
+        return application
+
+    def middleware(self, func):
+        """Like `make_middleware` but for decorating functions.
+
+        Example usage::
+
+            @manager.middleware
+            def application(environ, start_response):
+                ...
+
+        The difference to `make_middleware` is that the function passed
+        will have all the arguments copied from the inner application
+        (name, docstring, module).
+        """
+        return update_wrapper(self.make_middleware(func), func)
+
+    def __repr__(self):
+        return "<%s storages: %d>" % (self.__class__.__name__, len(self.locals))
+
+
+@implements_bool
+class LocalProxy(object):
+    """Acts as a proxy for a werkzeug local.  Forwards all operations to
+    a proxied object.  The only operations not supported for forwarding
+    are right handed operands and any kind of assignment.
+
+    Example usage::
+
+        from werkzeug.local import Local
+        l = Local()
+
+        # these are proxies
+        request = l('request')
+        user = l('user')
+
+
+        from werkzeug.local import LocalStack
+        _response_local = LocalStack()
+
+        # this is a proxy
+        response = _response_local()
+
+    Whenever something is bound to l.user / l.request the proxy objects
+    will forward all operations.  If no object is bound a :exc:`RuntimeError`
+    will be raised.
+
+    To create proxies to :class:`Local` or :class:`LocalStack` objects,
+    call the object as shown above.  If you want to have a proxy to an
+    object looked up by a function, you can (as of Werkzeug 0.6.1) pass
+    a function to the :class:`LocalProxy` constructor::
+
+        session = LocalProxy(lambda: get_current_request().session)
+
+    .. versionchanged:: 0.6.1
+       The class can be instantiated with a callable as well now.
+    """
+
+    __slots__ = ("__local", "__dict__", "__name__", "__wrapped__")
+
+    def __init__(self, local, name=None):
+        object.__setattr__(self, "_LocalProxy__local", local)
+        object.__setattr__(self, "__name__", name)
+        if callable(local) and not hasattr(local, "__release_local__"):
+            # "local" is a callable that is not an instance of Local or
+            # LocalManager: mark it as a wrapped function.
+            object.__setattr__(self, "__wrapped__", local)
+
+    def _get_current_object(self):
+        """Return the current object.  This is useful if you want the real
+        object behind the proxy at a time for performance reasons or because
+        you want to pass the object into a different context.
+        """
+        if not hasattr(self.__local, "__release_local__"):
+            return self.__local()
+        try:
+            return getattr(self.__local, self.__name__)
+        except AttributeError:
+            raise RuntimeError("no object bound to %s" % self.__name__)
+
+    @property
+    def __dict__(self):
+        try:
+            return self._get_current_object().__dict__
+        except RuntimeError:
+            raise AttributeError("__dict__")
+
+    def __repr__(self):
+        try:
+            obj = self._get_current_object()
+        except RuntimeError:
+            return "<%s unbound>" % self.__class__.__name__
+        return repr(obj)
+
+    def __bool__(self):
+        try:
+            return bool(self._get_current_object())
+        except RuntimeError:
+            return False
+
+    def __unicode__(self):
+        try:
+            return unicode(self._get_current_object())  # noqa
+        except RuntimeError:
+            return repr(self)
+
+    def __dir__(self):
+        try:
+            return dir(self._get_current_object())
+        except RuntimeError:
+            return []
+
+    def __getattr__(self, name):
+        if name == "__members__":
+            return dir(self._get_current_object())
+        return getattr(self._get_current_object(), name)
+
+    def __setitem__(self, key, value):
+        self._get_current_object()[key] = value
+
+    def __delitem__(self, key):
+        del self._get_current_object()[key]
+
+    if PY2:
+        __getslice__ = lambda x, i, j: x._get_current_object()[i:j]
+
+        def __setslice__(self, i, j, seq):
+            self._get_current_object()[i:j] = seq
+
+        def __delslice__(self, i, j):
+            del self._get_current_object()[i:j]
+
+    __setattr__ = lambda x, n, v: setattr(x._get_current_object(), n, v)
+    __delattr__ = lambda x, n: delattr(x._get_current_object(), n)
+    __str__ = lambda x: str(x._get_current_object())
+    __lt__ = lambda x, o: x._get_current_object() < o
+    __le__ = lambda x, o: x._get_current_object() <= o
+    __eq__ = lambda x, o: x._get_current_object() == o
+    __ne__ = lambda x, o: x._get_current_object() != o
+    __gt__ = lambda x, o: x._get_current_object() > o
+    __ge__ = lambda x, o: x._get_current_object() >= o
+    __cmp__ = lambda x, o: cmp(x._get_current_object(), o)  # noqa
+    __hash__ = lambda x: hash(x._get_current_object())
+    __call__ = lambda x, *a, **kw: x._get_current_object()(*a, **kw)
+    __len__ = lambda x: len(x._get_current_object())
+    __getitem__ = lambda x, i: x._get_current_object()[i]
+    __iter__ = lambda x: iter(x._get_current_object())
+    __contains__ = lambda x, i: i in x._get_current_object()
+    __add__ = lambda x, o: x._get_current_object() + o
+    __sub__ = lambda x, o: x._get_current_object() - o
+    __mul__ = lambda x, o: x._get_current_object() * o
+    __floordiv__ = lambda x, o: x._get_current_object() // o
+    __mod__ = lambda x, o: x._get_current_object() % o
+    __divmod__ = lambda x, o: x._get_current_object().__divmod__(o)
+    __pow__ = lambda x, o: x._get_current_object() ** o
+    __lshift__ = lambda x, o: x._get_current_object() << o
+    __rshift__ = lambda x, o: x._get_current_object() >> o
+    __and__ = lambda x, o: x._get_current_object() & o
+    __xor__ = lambda x, o: x._get_current_object() ^ o
+    __or__ = lambda x, o: x._get_current_object() | o
+    __div__ = lambda x, o: x._get_current_object().__div__(o)
+    __truediv__ = lambda x, o: x._get_current_object().__truediv__(o)
+    __neg__ = lambda x: -(x._get_current_object())
+    __pos__ = lambda x: +(x._get_current_object())
+    __abs__ = lambda x: abs(x._get_current_object())
+    __invert__ = lambda x: ~(x._get_current_object())
+    __complex__ = lambda x: complex(x._get_current_object())
+    __int__ = lambda x: int(x._get_current_object())
+    __long__ = lambda x: long(x._get_current_object())  # noqa
+    __float__ = lambda x: float(x._get_current_object())
+    __oct__ = lambda x: oct(x._get_current_object())
+    __hex__ = lambda x: hex(x._get_current_object())
+    __index__ = lambda x: x._get_current_object().__index__()
+    __coerce__ = lambda x, o: x._get_current_object().__coerce__(x, o)
+    __enter__ = lambda x: x._get_current_object().__enter__()
+    __exit__ = lambda x, *a, **kw: x._get_current_object().__exit__(*a, **kw)
+    __radd__ = lambda x, o: o + x._get_current_object()
+    __rsub__ = lambda x, o: o - x._get_current_object()
+    __rmul__ = lambda x, o: o * x._get_current_object()
+    __rdiv__ = lambda x, o: o / x._get_current_object()
+    if PY2:
+        __rtruediv__ = lambda x, o: x._get_current_object().__rtruediv__(o)
+    else:
+        __rtruediv__ = __rdiv__
+    __rfloordiv__ = lambda x, o: o // x._get_current_object()
+    __rmod__ = lambda x, o: o % x._get_current_object()
+    __rdivmod__ = lambda x, o: x._get_current_object().__rdivmod__(o)
+    __copy__ = lambda x: copy.copy(x._get_current_object())
+    __deepcopy__ = lambda x, memo: copy.deepcopy(x._get_current_object(), memo)
diff --git a/python/werkzeug/middleware/__init__.py b/python/werkzeug/middleware/__init__.py
new file mode 100644
index 0000000..5e049f5
--- /dev/null
+++ b/python/werkzeug/middleware/__init__.py
@@ -0,0 +1,25 @@
+"""
+Middleware
+==========
+
+A WSGI middleware is a WSGI application that wraps another application
+in order to observe or change its behavior. Werkzeug provides some
+middleware for common use cases.
+
+.. toctree::
+    :maxdepth: 1
+
+    proxy_fix
+    shared_data
+    dispatcher
+    http_proxy
+    lint
+    profiler
+
+The :doc:`interactive debugger </debug>` is also a middleware that can
+be applied manually, although it is typically used automatically with
+the :doc:`development server </serving>`.
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
diff --git a/python/werkzeug/middleware/dispatcher.py b/python/werkzeug/middleware/dispatcher.py
new file mode 100644
index 0000000..2eb173e
--- /dev/null
+++ b/python/werkzeug/middleware/dispatcher.py
@@ -0,0 +1,66 @@
+"""
+Application Dispatcher
+======================
+
+This middleware creates a single WSGI application that dispatches to
+multiple other WSGI applications mounted at different URL paths.
+
+A common example is writing a Single Page Application, where you have a
+backend API and a frontend written in JavaScript that does the routing
+in the browser rather than requesting different pages from the server.
+The frontend is a single HTML and JS file that should be served for any
+path besides "/api".
+
+This example dispatches to an API app under "/api", an admin app
+under "/admin", and an app that serves frontend files for all other
+requests::
+
+    app = DispatcherMiddleware(serve_frontend, {
+        '/api': api_app,
+        '/admin': admin_app,
+    })
+
+In production, you might instead handle this at the HTTP server level,
+serving files or proxying to application servers based on location. The
+API and admin apps would each be deployed with a separate WSGI server,
+and the static files would be served directly by the HTTP server.
+
+.. autoclass:: DispatcherMiddleware
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+
+
+class DispatcherMiddleware(object):
+    """Combine multiple applications as a single WSGI application.
+    Requests are dispatched to an application based on the path it is
+    mounted under.
+
+    :param app: The WSGI application to dispatch to if the request
+        doesn't match a mounted path.
+    :param mounts: Maps path prefixes to applications for dispatching.
+    """
+
+    def __init__(self, app, mounts=None):
+        self.app = app
+        self.mounts = mounts or {}
+
+    def __call__(self, environ, start_response):
+        script = environ.get("PATH_INFO", "")
+        path_info = ""
+
+        while "/" in script:
+            if script in self.mounts:
+                app = self.mounts[script]
+                break
+
+            script, last_item = script.rsplit("/", 1)
+            path_info = "/%s%s" % (last_item, path_info)
+        else:
+            app = self.mounts.get(script, self.app)
+
+        original_script_name = environ.get("SCRIPT_NAME", "")
+        environ["SCRIPT_NAME"] = original_script_name + script
+        environ["PATH_INFO"] = path_info
+        return app(environ, start_response)
diff --git a/python/werkzeug/middleware/http_proxy.py b/python/werkzeug/middleware/http_proxy.py
new file mode 100644
index 0000000..bfdc071
--- /dev/null
+++ b/python/werkzeug/middleware/http_proxy.py
@@ -0,0 +1,219 @@
+"""
+Basic HTTP Proxy
+================
+
+.. autoclass:: ProxyMiddleware
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+import socket
+
+from ..datastructures import EnvironHeaders
+from ..http import is_hop_by_hop_header
+from ..urls import url_parse
+from ..urls import url_quote
+from ..wsgi import get_input_stream
+
+try:
+    from http import client
+except ImportError:
+    import httplib as client
+
+
+class ProxyMiddleware(object):
+    """Proxy requests under a path to an external server, routing other
+    requests to the app.
+
+    This middleware can only proxy HTTP requests, as that is the only
+    protocol handled by the WSGI server. Other protocols, such as
+    websocket requests, cannot be proxied at this layer. This should
+    only be used for development, in production a real proxying server
+    should be used.
+
+    The middleware takes a dict that maps a path prefix to a dict
+    describing the host to be proxied to::
+
+        app = ProxyMiddleware(app, {
+            "/static/": {
+                "target": "http://127.0.0.1:5001/",
+            }
+        })
+
+    Each host has the following options:
+
+    ``target``:
+        The target URL to dispatch to. This is required.
+    ``remove_prefix``:
+        Whether to remove the prefix from the URL before dispatching it
+        to the target. The default is ``False``.
+    ``host``:
+        ``"<auto>"`` (default):
+            The host header is automatically rewritten to the URL of the
+            target.
+        ``None``:
+            The host header is unmodified from the client request.
+        Any other value:
+            The host header is overwritten with the value.
+    ``headers``:
+        A dictionary of headers to be sent with the request to the
+        target. The default is ``{}``.
+    ``ssl_context``:
+        A :class:`ssl.SSLContext` defining how to verify requests if the
+        target is HTTPS. The default is ``None``.
+
+    In the example above, everything under ``"/static/"`` is proxied to
+    the server on port 5001. The host header is rewritten to the target,
+    and the ``"/static/"`` prefix is removed from the URLs.
+
+    :param app: The WSGI application to wrap.
+    :param targets: Proxy target configurations. See description above.
+    :param chunk_size: Size of chunks to read from input stream and
+        write to target.
+    :param timeout: Seconds before an operation to a target fails.
+
+    .. versionadded:: 0.14
+    """
+
+    def __init__(self, app, targets, chunk_size=2 << 13, timeout=10):
+        def _set_defaults(opts):
+            opts.setdefault("remove_prefix", False)
+            opts.setdefault("host", "<auto>")
+            opts.setdefault("headers", {})
+            opts.setdefault("ssl_context", None)
+            return opts
+
+        self.app = app
+        self.targets = dict(
+            ("/%s/" % k.strip("/"), _set_defaults(v)) for k, v in targets.items()
+        )
+        self.chunk_size = chunk_size
+        self.timeout = timeout
+
+    def proxy_to(self, opts, path, prefix):
+        target = url_parse(opts["target"])
+
+        def application(environ, start_response):
+            headers = list(EnvironHeaders(environ).items())
+            headers[:] = [
+                (k, v)
+                for k, v in headers
+                if not is_hop_by_hop_header(k)
+                and k.lower() not in ("content-length", "host")
+            ]
+            headers.append(("Connection", "close"))
+
+            if opts["host"] == "<auto>":
+                headers.append(("Host", target.ascii_host))
+            elif opts["host"] is None:
+                headers.append(("Host", environ["HTTP_HOST"]))
+            else:
+                headers.append(("Host", opts["host"]))
+
+            headers.extend(opts["headers"].items())
+            remote_path = path
+
+            if opts["remove_prefix"]:
+                remote_path = "%s/%s" % (
+                    target.path.rstrip("/"),
+                    remote_path[len(prefix) :].lstrip("/"),
+                )
+
+            content_length = environ.get("CONTENT_LENGTH")
+            chunked = False
+
+            if content_length not in ("", None):
+                headers.append(("Content-Length", content_length))
+            elif content_length is not None:
+                headers.append(("Transfer-Encoding", "chunked"))
+                chunked = True
+
+            try:
+                if target.scheme == "http":
+                    con = client.HTTPConnection(
+                        target.ascii_host, target.port or 80, timeout=self.timeout
+                    )
+                elif target.scheme == "https":
+                    con = client.HTTPSConnection(
+                        target.ascii_host,
+                        target.port or 443,
+                        timeout=self.timeout,
+                        context=opts["ssl_context"],
+                    )
+                else:
+                    raise RuntimeError(
+                        "Target scheme must be 'http' or 'https', got '{}'.".format(
+                            target.scheme
+                        )
+                    )
+
+                con.connect()
+                remote_url = url_quote(remote_path)
+                querystring = environ["QUERY_STRING"]
+
+                if querystring:
+                    remote_url = remote_url + "?" + querystring
+
+                con.putrequest(environ["REQUEST_METHOD"], remote_url, skip_host=True)
+
+                for k, v in headers:
+                    if k.lower() == "connection":
+                        v = "close"
+
+                    con.putheader(k, v)
+
+                con.endheaders()
+                stream = get_input_stream(environ)
+
+                while 1:
+                    data = stream.read(self.chunk_size)
+
+                    if not data:
+                        break
+
+                    if chunked:
+                        con.send(b"%x\r\n%s\r\n" % (len(data), data))
+                    else:
+                        con.send(data)
+
+                resp = con.getresponse()
+            except socket.error:
+                from ..exceptions import BadGateway
+
+                return BadGateway()(environ, start_response)
+
+            start_response(
+                "%d %s" % (resp.status, resp.reason),
+                [
+                    (k.title(), v)
+                    for k, v in resp.getheaders()
+                    if not is_hop_by_hop_header(k)
+                ],
+            )
+
+            def read():
+                while 1:
+                    try:
+                        data = resp.read(self.chunk_size)
+                    except socket.error:
+                        break
+
+                    if not data:
+                        break
+
+                    yield data
+
+            return read()
+
+        return application
+
+    def __call__(self, environ, start_response):
+        path = environ["PATH_INFO"]
+        app = self.app
+
+        for prefix, opts in self.targets.items():
+            if path.startswith(prefix):
+                app = self.proxy_to(opts, path, prefix)
+                break
+
+        return app(environ, start_response)
diff --git a/python/werkzeug/middleware/lint.py b/python/werkzeug/middleware/lint.py
new file mode 100644
index 0000000..98f9581
--- /dev/null
+++ b/python/werkzeug/middleware/lint.py
@@ -0,0 +1,408 @@
+"""
+WSGI Protocol Linter
+====================
+
+This module provides a middleware that performs sanity checks on the
+behavior of the WSGI server and application. It checks that the
+:pep:`3333` WSGI spec is properly implemented. It also warns on some
+common HTTP errors such as non-empty responses for 304 status codes.
+
+.. autoclass:: LintMiddleware
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+from warnings import warn
+
+from .._compat import implements_iterator
+from .._compat import PY2
+from .._compat import string_types
+from ..datastructures import Headers
+from ..http import is_entity_header
+from ..wsgi import FileWrapper
+
+try:
+    from urllib.parse import urlparse
+except ImportError:
+    from urlparse import urlparse
+
+
+class WSGIWarning(Warning):
+    """Warning class for WSGI warnings."""
+
+
+class HTTPWarning(Warning):
+    """Warning class for HTTP warnings."""
+
+
+def check_string(context, obj, stacklevel=3):
+    if type(obj) is not str:
+        warn(
+            "'%s' requires strings, got '%s'" % (context, type(obj).__name__),
+            WSGIWarning,
+        )
+
+
+class InputStream(object):
+    def __init__(self, stream):
+        self._stream = stream
+
+    def read(self, *args):
+        if len(args) == 0:
+            warn(
+                "WSGI does not guarantee an EOF marker on the input stream, thus making"
+                " calls to 'wsgi.input.read()' unsafe. Conforming servers may never"
+                " return from this call.",
+                WSGIWarning,
+                stacklevel=2,
+            )
+        elif len(args) != 1:
+            warn(
+                "Too many parameters passed to 'wsgi.input.read()'.",
+                WSGIWarning,
+                stacklevel=2,
+            )
+        return self._stream.read(*args)
+
+    def readline(self, *args):
+        if len(args) == 0:
+            warn(
+                "Calls to 'wsgi.input.readline()' without arguments are unsafe. Use"
+                " 'wsgi.input.read()' instead.",
+                WSGIWarning,
+                stacklevel=2,
+            )
+        elif len(args) == 1:
+            warn(
+                "'wsgi.input.readline()' was called with a size hint. WSGI does not"
+                " support this, although it's available on all major servers.",
+                WSGIWarning,
+                stacklevel=2,
+            )
+        else:
+            raise TypeError("Too many arguments passed to 'wsgi.input.readline()'.")
+        return self._stream.readline(*args)
+
+    def __iter__(self):
+        try:
+            return iter(self._stream)
+        except TypeError:
+            warn("'wsgi.input' is not iterable.", WSGIWarning, stacklevel=2)
+            return iter(())
+
+    def close(self):
+        warn("The application closed the input stream!", WSGIWarning, stacklevel=2)
+        self._stream.close()
+
+
+class ErrorStream(object):
+    def __init__(self, stream):
+        self._stream = stream
+
+    def write(self, s):
+        check_string("wsgi.error.write()", s)
+        self._stream.write(s)
+
+    def flush(self):
+        self._stream.flush()
+
+    def writelines(self, seq):
+        for line in seq:
+            self.write(line)
+
+    def close(self):
+        warn("The application closed the error stream!", WSGIWarning, stacklevel=2)
+        self._stream.close()
+
+
+class GuardedWrite(object):
+    def __init__(self, write, chunks):
+        self._write = write
+        self._chunks = chunks
+
+    def __call__(self, s):
+        check_string("write()", s)
+        self._write.write(s)
+        self._chunks.append(len(s))
+
+
+@implements_iterator
+class GuardedIterator(object):
+    def __init__(self, iterator, headers_set, chunks):
+        self._iterator = iterator
+        if PY2:
+            self._next = iter(iterator).next
+        else:
+            self._next = iter(iterator).__next__
+        self.closed = False
+        self.headers_set = headers_set
+        self.chunks = chunks
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.closed:
+            warn("Iterated over closed 'app_iter'.", WSGIWarning, stacklevel=2)
+
+        rv = self._next()
+
+        if not self.headers_set:
+            warn(
+                "The application returned before it started the response.",
+                WSGIWarning,
+                stacklevel=2,
+            )
+
+        check_string("application iterator items", rv)
+        self.chunks.append(len(rv))
+        return rv
+
+    def close(self):
+        self.closed = True
+
+        if hasattr(self._iterator, "close"):
+            self._iterator.close()
+
+        if self.headers_set:
+            status_code, headers = self.headers_set
+            bytes_sent = sum(self.chunks)
+            content_length = headers.get("content-length", type=int)
+
+            if status_code == 304:
+                for key, _value in headers:
+                    key = key.lower()
+                    if key not in ("expires", "content-location") and is_entity_header(
+                        key
+                    ):
+                        warn(
+                            "Entity header %r found in 304 response." % key, HTTPWarning
+                        )
+                if bytes_sent:
+                    warn("304 responses must not have a body.", HTTPWarning)
+            elif 100 <= status_code < 200 or status_code == 204:
+                if content_length != 0:
+                    warn(
+                        "%r responses must have an empty content length." % status_code,
+                        HTTPWarning,
+                    )
+                if bytes_sent:
+                    warn(
+                        "%r responses must not have a body." % status_code, HTTPWarning
+                    )
+            elif content_length is not None and content_length != bytes_sent:
+                warn(
+                    "Content-Length and the number of bytes sent to the client do not"
+                    " match.",
+                    WSGIWarning,
+                )
+
+    def __del__(self):
+        if not self.closed:
+            try:
+                warn(
+                    "Iterator was garbage collected before it was closed.", WSGIWarning
+                )
+            except Exception:
+                pass
+
+
+class LintMiddleware(object):
+    """Warns about common errors in the WSGI and HTTP behavior of the
+    server and wrapped application. Some of the issues it check are:
+
+    -   invalid status codes
+    -   non-bytestrings sent to the WSGI server
+    -   strings returned from the WSGI application
+    -   non-empty conditional responses
+    -   unquoted etags
+    -   relative URLs in the Location header
+    -   unsafe calls to wsgi.input
+    -   unclosed iterators
+
+    Error information is emitted using the :mod:`warnings` module.
+
+    :param app: The WSGI application to wrap.
+
+    .. code-block:: python
+
+        from werkzeug.middleware.lint import LintMiddleware
+        app = LintMiddleware(app)
+    """
+
+    def __init__(self, app):
+        self.app = app
+
+    def check_environ(self, environ):
+        if type(environ) is not dict:
+            warn(
+                "WSGI environment is not a standard Python dict.",
+                WSGIWarning,
+                stacklevel=4,
+            )
+        for key in (
+            "REQUEST_METHOD",
+            "SERVER_NAME",
+            "SERVER_PORT",
+            "wsgi.version",
+            "wsgi.input",
+            "wsgi.errors",
+            "wsgi.multithread",
+            "wsgi.multiprocess",
+            "wsgi.run_once",
+        ):
+            if key not in environ:
+                warn(
+                    "Required environment key %r not found" % key,
+                    WSGIWarning,
+                    stacklevel=3,
+                )
+        if environ["wsgi.version"] != (1, 0):
+            warn("Environ is not a WSGI 1.0 environ.", WSGIWarning, stacklevel=3)
+
+        script_name = environ.get("SCRIPT_NAME", "")
+        path_info = environ.get("PATH_INFO", "")
+
+        if script_name and script_name[0] != "/":
+            warn(
+                "'SCRIPT_NAME' does not start with a slash: %r" % script_name,
+                WSGIWarning,
+                stacklevel=3,
+            )
+
+        if path_info and path_info[0] != "/":
+            warn(
+                "'PATH_INFO' does not start with a slash: %r" % path_info,
+                WSGIWarning,
+                stacklevel=3,
+            )
+
+    def check_start_response(self, status, headers, exc_info):
+        check_string("status", status)
+        status_code = status.split(None, 1)[0]
+
+        if len(status_code) != 3 or not status_code.isdigit():
+            warn(WSGIWarning("Status code must be three digits"), stacklevel=3)
+
+        if len(status) < 4 or status[3] != " ":
+            warn(
+                WSGIWarning(
+                    "Invalid value for status %r.  Valid "
+                    "status strings are three digits, a space "
+                    "and a status explanation"
+                ),
+                stacklevel=3,
+            )
+
+        status_code = int(status_code)
+
+        if status_code < 100:
+            warn(WSGIWarning("status code < 100 detected"), stacklevel=3)
+
+        if type(headers) is not list:
+            warn(WSGIWarning("header list is not a list"), stacklevel=3)
+
+        for item in headers:
+            if type(item) is not tuple or len(item) != 2:
+                warn(WSGIWarning("Headers must tuple 2-item tuples"), stacklevel=3)
+            name, value = item
+            if type(name) is not str or type(value) is not str:
+                warn(WSGIWarning("header items must be strings"), stacklevel=3)
+            if name.lower() == "status":
+                warn(
+                    WSGIWarning(
+                        "The status header is not supported due to "
+                        "conflicts with the CGI spec."
+                    ),
+                    stacklevel=3,
+                )
+
+        if exc_info is not None and not isinstance(exc_info, tuple):
+            warn(WSGIWarning("invalid value for exc_info"), stacklevel=3)
+
+        headers = Headers(headers)
+        self.check_headers(headers)
+
+        return status_code, headers
+
+    def check_headers(self, headers):
+        etag = headers.get("etag")
+
+        if etag is not None:
+            if etag.startswith(("W/", "w/")):
+                if etag.startswith("w/"):
+                    warn(
+                        HTTPWarning("weak etag indicator should be upcase."),
+                        stacklevel=4,
+                    )
+
+                etag = etag[2:]
+
+            if not (etag[:1] == etag[-1:] == '"'):
+                warn(HTTPWarning("unquoted etag emitted."), stacklevel=4)
+
+        location = headers.get("location")
+
+        if location is not None:
+            if not urlparse(location).netloc:
+                warn(
+                    HTTPWarning("absolute URLs required for location header"),
+                    stacklevel=4,
+                )
+
+    def check_iterator(self, app_iter):
+        if isinstance(app_iter, string_types):
+            warn(
+                "The application returned astring. The response will send one character"
+                " at a time to the client, which will kill performance. Return a list"
+                " or iterable instead.",
+                WSGIWarning,
+                stacklevel=3,
+            )
+
+    def __call__(self, *args, **kwargs):
+        if len(args) != 2:
+            warn("A WSGI app takes two arguments.", WSGIWarning, stacklevel=2)
+
+        if kwargs:
+            warn(
+                "A WSGI app does not take keyword arguments.", WSGIWarning, stacklevel=2
+            )
+
+        environ, start_response = args
+
+        self.check_environ(environ)
+        environ["wsgi.input"] = InputStream(environ["wsgi.input"])
+        environ["wsgi.errors"] = ErrorStream(environ["wsgi.errors"])
+
+        # Hook our own file wrapper in so that applications will always
+        # iterate to the end and we can check the content length.
+        environ["wsgi.file_wrapper"] = FileWrapper
+
+        headers_set = []
+        chunks = []
+
+        def checking_start_response(*args, **kwargs):
+            if len(args) not in (2, 3):
+                warn(
+                    "Invalid number of arguments: %s, expected 2 or 3." % len(args),
+                    WSGIWarning,
+                    stacklevel=2,
+                )
+
+            if kwargs:
+                warn("'start_response' does not take keyword arguments.", WSGIWarning)
+
+            status, headers = args[:2]
+
+            if len(args) == 3:
+                exc_info = args[2]
+            else:
+                exc_info = None
+
+            headers_set[:] = self.check_start_response(status, headers, exc_info)
+            return GuardedWrite(start_response(status, headers, exc_info), chunks)
+
+        app_iter = self.app(environ, checking_start_response)
+        self.check_iterator(app_iter)
+        return GuardedIterator(app_iter, headers_set, chunks)
diff --git a/python/werkzeug/middleware/profiler.py b/python/werkzeug/middleware/profiler.py
new file mode 100644
index 0000000..32a14d9
--- /dev/null
+++ b/python/werkzeug/middleware/profiler.py
@@ -0,0 +1,132 @@
+"""
+Application Profiler
+====================
+
+This module provides a middleware that profiles each request with the
+:mod:`cProfile` module. This can help identify bottlenecks in your code
+that may be slowing down your application.
+
+.. autoclass:: ProfilerMiddleware
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+from __future__ import print_function
+
+import os.path
+import sys
+import time
+from pstats import Stats
+
+try:
+    from cProfile import Profile
+except ImportError:
+    from profile import Profile
+
+
+class ProfilerMiddleware(object):
+    """Wrap a WSGI application and profile the execution of each
+    request. Responses are buffered so that timings are more exact.
+
+    If ``stream`` is given, :class:`pstats.Stats` are written to it
+    after each request. If ``profile_dir`` is given, :mod:`cProfile`
+    data files are saved to that directory, one file per request.
+
+    The filename can be customized by passing ``filename_format``. If
+    it is a string, it will be formatted using :meth:`str.format` with
+    the following fields available:
+
+    -   ``{method}`` - The request method; GET, POST, etc.
+    -   ``{path}`` - The request path or 'root' should one not exist.
+    -   ``{elapsed}`` - The elapsed time of the request.
+    -   ``{time}`` - The time of the request.
+
+    If it is a callable, it will be called with the WSGI ``environ``
+    dict and should return a filename.
+
+    :param app: The WSGI application to wrap.
+    :param stream: Write stats to this stream. Disable with ``None``.
+    :param sort_by: A tuple of columns to sort stats by. See
+        :meth:`pstats.Stats.sort_stats`.
+    :param restrictions: A tuple of restrictions to filter stats by. See
+        :meth:`pstats.Stats.print_stats`.
+    :param profile_dir: Save profile data files to this directory.
+    :param filename_format: Format string for profile data file names,
+        or a callable returning a name. See explanation above.
+
+    .. code-block:: python
+
+        from werkzeug.middleware.profiler import ProfilerMiddleware
+        app = ProfilerMiddleware(app)
+
+    .. versionchanged:: 0.15
+        Stats are written even if ``profile_dir`` is given, and can be
+        disable by passing ``stream=None``.
+
+    .. versionadded:: 0.15
+        Added ``filename_format``.
+
+    .. versionadded:: 0.9
+        Added ``restrictions`` and ``profile_dir``.
+    """
+
+    def __init__(
+        self,
+        app,
+        stream=sys.stdout,
+        sort_by=("time", "calls"),
+        restrictions=(),
+        profile_dir=None,
+        filename_format="{method}.{path}.{elapsed:.0f}ms.{time:.0f}.prof",
+    ):
+        self._app = app
+        self._stream = stream
+        self._sort_by = sort_by
+        self._restrictions = restrictions
+        self._profile_dir = profile_dir
+        self._filename_format = filename_format
+
+    def __call__(self, environ, start_response):
+        response_body = []
+
+        def catching_start_response(status, headers, exc_info=None):
+            start_response(status, headers, exc_info)
+            return response_body.append
+
+        def runapp():
+            app_iter = self._app(environ, catching_start_response)
+            response_body.extend(app_iter)
+
+            if hasattr(app_iter, "close"):
+                app_iter.close()
+
+        profile = Profile()
+        start = time.time()
+        profile.runcall(runapp)
+        body = b"".join(response_body)
+        elapsed = time.time() - start
+
+        if self._profile_dir is not None:
+            if callable(self._filename_format):
+                filename = self._filename_format(environ)
+            else:
+                filename = self._filename_format.format(
+                    method=environ["REQUEST_METHOD"],
+                    path=(
+                        environ.get("PATH_INFO").strip("/").replace("/", ".") or "root"
+                    ),
+                    elapsed=elapsed * 1000.0,
+                    time=time.time(),
+                )
+            filename = os.path.join(self._profile_dir, filename)
+            profile.dump_stats(filename)
+
+        if self._stream is not None:
+            stats = Stats(profile, stream=self._stream)
+            stats.sort_stats(*self._sort_by)
+            print("-" * 80, file=self._stream)
+            print("PATH: {!r}".format(environ.get("PATH_INFO", "")), file=self._stream)
+            stats.print_stats(*self._restrictions)
+            print("-" * 80 + "\n", file=self._stream)
+
+        return [body]
diff --git a/python/werkzeug/middleware/proxy_fix.py b/python/werkzeug/middleware/proxy_fix.py
new file mode 100644
index 0000000..dc1dacc
--- /dev/null
+++ b/python/werkzeug/middleware/proxy_fix.py
@@ -0,0 +1,228 @@
+"""
+X-Forwarded-For Proxy Fix
+=========================
+
+This module provides a middleware that adjusts the WSGI environ based on
+``X-Forwarded-`` headers that proxies in front of an application may
+set.
+
+When an application is running behind a proxy server, WSGI may see the
+request as coming from that server rather than the real client. Proxies
+set various headers to track where the request actually came from.
+
+This middleware should only be applied if the application is actually
+behind such a proxy, and should be configured with the number of proxies
+that are chained in front of it. Not all proxies set all the headers.
+Since incoming headers can be faked, you must set how many proxies are
+setting each header so the middleware knows what to trust.
+
+.. autoclass:: ProxyFix
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+import warnings
+
+
+class ProxyFix(object):
+    """Adjust the WSGI environ based on ``X-Forwarded-`` that proxies in
+    front of the application may set.
+
+    -   ``X-Forwarded-For`` sets ``REMOTE_ADDR``.
+    -   ``X-Forwarded-Proto`` sets ``wsgi.url_scheme``.
+    -   ``X-Forwarded-Host`` sets ``HTTP_HOST``, ``SERVER_NAME``, and
+        ``SERVER_PORT``.
+    -   ``X-Forwarded-Port`` sets ``HTTP_HOST`` and ``SERVER_PORT``.
+    -   ``X-Forwarded-Prefix`` sets ``SCRIPT_NAME``.
+
+    You must tell the middleware how many proxies set each header so it
+    knows what values to trust. It is a security issue to trust values
+    that came from the client rather than a proxy.
+
+    The original values of the headers are stored in the WSGI
+    environ as ``werkzeug.proxy_fix.orig``, a dict.
+
+    :param app: The WSGI application to wrap.
+    :param x_for: Number of values to trust for ``X-Forwarded-For``.
+    :param x_proto: Number of values to trust for ``X-Forwarded-Proto``.
+    :param x_host: Number of values to trust for ``X-Forwarded-Host``.
+    :param x_port: Number of values to trust for ``X-Forwarded-Port``.
+    :param x_prefix: Number of values to trust for
+        ``X-Forwarded-Prefix``.
+    :param num_proxies: Deprecated, use ``x_for`` instead.
+
+    .. code-block:: python
+
+        from werkzeug.middleware.proxy_fix import ProxyFix
+        # App is behind one proxy that sets the -For and -Host headers.
+        app = ProxyFix(app, x_for=1, x_host=1)
+
+    .. versionchanged:: 0.15
+        All headers support multiple values. The ``num_proxies``
+        argument is deprecated. Each header is configured with a
+        separate number of trusted proxies.
+
+    .. versionchanged:: 0.15
+        Original WSGI environ values are stored in the
+        ``werkzeug.proxy_fix.orig`` dict. ``orig_remote_addr``,
+        ``orig_wsgi_url_scheme``, and ``orig_http_host`` are deprecated
+        and will be removed in 1.0.
+
+    .. versionchanged:: 0.15
+        Support ``X-Forwarded-Port`` and ``X-Forwarded-Prefix``.
+
+    .. versionchanged:: 0.15
+        ``X-Fowarded-Host`` and ``X-Forwarded-Port`` modify
+        ``SERVER_NAME`` and ``SERVER_PORT``.
+    """
+
+    def __init__(
+        self, app, num_proxies=None, x_for=1, x_proto=0, x_host=0, x_port=0, x_prefix=0
+    ):
+        self.app = app
+        self.x_for = x_for
+        self.x_proto = x_proto
+        self.x_host = x_host
+        self.x_port = x_port
+        self.x_prefix = x_prefix
+        self.num_proxies = num_proxies
+
+    @property
+    def num_proxies(self):
+        """The number of proxies setting ``X-Forwarded-For`` in front
+        of the application.
+
+        .. deprecated:: 0.15
+            A separate number of trusted proxies is configured for each
+            header. ``num_proxies`` maps to ``x_for``. This method will
+            be removed in 1.0.
+
+        :internal:
+        """
+        warnings.warn(
+            "'num_proxies' is deprecated as of version 0.15 and will be"
+            " removed in version 1.0. Use 'x_for' instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return self.x_for
+
+    @num_proxies.setter
+    def num_proxies(self, value):
+        if value is not None:
+            warnings.warn(
+                "'num_proxies' is deprecated as of version 0.15 and"
+                " will be removed in version 1.0. Use 'x_for' instead.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            self.x_for = value
+
+    def get_remote_addr(self, forwarded_for):
+        """Get the real ``remote_addr`` by looking backwards ``x_for``
+        number of values in the ``X-Forwarded-For`` header.
+
+        :param forwarded_for: List of values parsed from the
+            ``X-Forwarded-For`` header.
+        :return: The real ``remote_addr``, or ``None`` if there were not
+            at least ``x_for`` values.
+
+        .. deprecated:: 0.15
+            This is handled internally for each header. This method will
+            be removed in 1.0.
+
+        .. versionchanged:: 0.9
+            Use ``num_proxies`` instead of always picking the first
+            value.
+
+        .. versionadded:: 0.8
+        """
+        warnings.warn(
+            "'get_remote_addr' is deprecated as of version 0.15 and"
+            " will be removed in version 1.0. It is now handled"
+            " internally for each header.",
+            DeprecationWarning,
+        )
+        return self._get_trusted_comma(self.x_for, ",".join(forwarded_for))
+
+    def _get_trusted_comma(self, trusted, value):
+        """Get the real value from a comma-separated header based on the
+        configured number of trusted proxies.
+
+        :param trusted: Number of values to trust in the header.
+        :param value: Header value to parse.
+        :return: The real value, or ``None`` if there are fewer values
+            than the number of trusted proxies.
+
+        .. versionadded:: 0.15
+        """
+        if not (trusted and value):
+            return
+        values = [x.strip() for x in value.split(",")]
+        if len(values) >= trusted:
+            return values[-trusted]
+
+    def __call__(self, environ, start_response):
+        """Modify the WSGI environ based on the various ``Forwarded``
+        headers before calling the wrapped application. Store the
+        original environ values in ``werkzeug.proxy_fix.orig_{key}``.
+        """
+        environ_get = environ.get
+        orig_remote_addr = environ_get("REMOTE_ADDR")
+        orig_wsgi_url_scheme = environ_get("wsgi.url_scheme")
+        orig_http_host = environ_get("HTTP_HOST")
+        environ.update(
+            {
+                "werkzeug.proxy_fix.orig": {
+                    "REMOTE_ADDR": orig_remote_addr,
+                    "wsgi.url_scheme": orig_wsgi_url_scheme,
+                    "HTTP_HOST": orig_http_host,
+                    "SERVER_NAME": environ_get("SERVER_NAME"),
+                    "SERVER_PORT": environ_get("SERVER_PORT"),
+                    "SCRIPT_NAME": environ_get("SCRIPT_NAME"),
+                },
+                # todo: remove deprecated keys
+                "werkzeug.proxy_fix.orig_remote_addr": orig_remote_addr,
+                "werkzeug.proxy_fix.orig_wsgi_url_scheme": orig_wsgi_url_scheme,
+                "werkzeug.proxy_fix.orig_http_host": orig_http_host,
+            }
+        )
+
+        x_for = self._get_trusted_comma(self.x_for, environ_get("HTTP_X_FORWARDED_FOR"))
+        if x_for:
+            environ["REMOTE_ADDR"] = x_for
+
+        x_proto = self._get_trusted_comma(
+            self.x_proto, environ_get("HTTP_X_FORWARDED_PROTO")
+        )
+        if x_proto:
+            environ["wsgi.url_scheme"] = x_proto
+
+        x_host = self._get_trusted_comma(
+            self.x_host, environ_get("HTTP_X_FORWARDED_HOST")
+        )
+        if x_host:
+            environ["HTTP_HOST"] = x_host
+            parts = x_host.split(":", 1)
+            environ["SERVER_NAME"] = parts[0]
+            if len(parts) == 2:
+                environ["SERVER_PORT"] = parts[1]
+
+        x_port = self._get_trusted_comma(
+            self.x_port, environ_get("HTTP_X_FORWARDED_PORT")
+        )
+        if x_port:
+            host = environ.get("HTTP_HOST")
+            if host:
+                parts = host.split(":", 1)
+                host = parts[0] if len(parts) == 2 else host
+                environ["HTTP_HOST"] = "%s:%s" % (host, x_port)
+            environ["SERVER_PORT"] = x_port
+
+        x_prefix = self._get_trusted_comma(
+            self.x_prefix, environ_get("HTTP_X_FORWARDED_PREFIX")
+        )
+        if x_prefix:
+            environ["SCRIPT_NAME"] = x_prefix
+
+        return self.app(environ, start_response)
diff --git a/python/werkzeug/middleware/shared_data.py b/python/werkzeug/middleware/shared_data.py
new file mode 100644
index 0000000..a902281
--- /dev/null
+++ b/python/werkzeug/middleware/shared_data.py
@@ -0,0 +1,260 @@
+"""
+Serve Shared Static Files
+=========================
+
+.. autoclass:: SharedDataMiddleware
+    :members: is_allowed
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+import mimetypes
+import os
+import posixpath
+from datetime import datetime
+from io import BytesIO
+from time import mktime
+from time import time
+from zlib import adler32
+
+from .._compat import PY2
+from .._compat import string_types
+from ..filesystem import get_filesystem_encoding
+from ..http import http_date
+from ..http import is_resource_modified
+from ..wsgi import get_path_info
+from ..wsgi import wrap_file
+
+
+class SharedDataMiddleware(object):
+
+    """A WSGI middleware that provides static content for development
+    environments or simple server setups. Usage is quite simple::
+
+        import os
+        from werkzeug.wsgi import SharedDataMiddleware
+
+        app = SharedDataMiddleware(app, {
+            '/static': os.path.join(os.path.dirname(__file__), 'static')
+        })
+
+    The contents of the folder ``./shared`` will now be available on
+    ``http://example.com/shared/``.  This is pretty useful during development
+    because a standalone media server is not required.  One can also mount
+    files on the root folder and still continue to use the application because
+    the shared data middleware forwards all unhandled requests to the
+    application, even if the requests are below one of the shared folders.
+
+    If `pkg_resources` is available you can also tell the middleware to serve
+    files from package data::
+
+        app = SharedDataMiddleware(app, {
+            '/static': ('myapplication', 'static')
+        })
+
+    This will then serve the ``static`` folder in the `myapplication`
+    Python package.
+
+    The optional `disallow` parameter can be a list of :func:`~fnmatch.fnmatch`
+    rules for files that are not accessible from the web.  If `cache` is set to
+    `False` no caching headers are sent.
+
+    Currently the middleware does not support non ASCII filenames.  If the
+    encoding on the file system happens to be the encoding of the URI it may
+    work but this could also be by accident.  We strongly suggest using ASCII
+    only file names for static files.
+
+    The middleware will guess the mimetype using the Python `mimetype`
+    module.  If it's unable to figure out the charset it will fall back
+    to `fallback_mimetype`.
+
+    .. versionchanged:: 0.5
+       The cache timeout is configurable now.
+
+    .. versionadded:: 0.6
+       The `fallback_mimetype` parameter was added.
+
+    :param app: the application to wrap.  If you don't want to wrap an
+                application you can pass it :exc:`NotFound`.
+    :param exports: a list or dict of exported files and folders.
+    :param disallow: a list of :func:`~fnmatch.fnmatch` rules.
+    :param fallback_mimetype: the fallback mimetype for unknown files.
+    :param cache: enable or disable caching headers.
+    :param cache_timeout: the cache timeout in seconds for the headers.
+    """
+
+    def __init__(
+        self,
+        app,
+        exports,
+        disallow=None,
+        cache=True,
+        cache_timeout=60 * 60 * 12,
+        fallback_mimetype="text/plain",
+    ):
+        self.app = app
+        self.exports = []
+        self.cache = cache
+        self.cache_timeout = cache_timeout
+
+        if hasattr(exports, "items"):
+            exports = exports.items()
+
+        for key, value in exports:
+            if isinstance(value, tuple):
+                loader = self.get_package_loader(*value)
+            elif isinstance(value, string_types):
+                if os.path.isfile(value):
+                    loader = self.get_file_loader(value)
+                else:
+                    loader = self.get_directory_loader(value)
+            else:
+                raise TypeError("unknown def %r" % value)
+
+            self.exports.append((key, loader))
+
+        if disallow is not None:
+            from fnmatch import fnmatch
+
+            self.is_allowed = lambda x: not fnmatch(x, disallow)
+
+        self.fallback_mimetype = fallback_mimetype
+
+    def is_allowed(self, filename):
+        """Subclasses can override this method to disallow the access to
+        certain files.  However by providing `disallow` in the constructor
+        this method is overwritten.
+        """
+        return True
+
+    def _opener(self, filename):
+        return lambda: (
+            open(filename, "rb"),
+            datetime.utcfromtimestamp(os.path.getmtime(filename)),
+            int(os.path.getsize(filename)),
+        )
+
+    def get_file_loader(self, filename):
+        return lambda x: (os.path.basename(filename), self._opener(filename))
+
+    def get_package_loader(self, package, package_path):
+        from pkg_resources import DefaultProvider, ResourceManager, get_provider
+
+        loadtime = datetime.utcnow()
+        provider = get_provider(package)
+        manager = ResourceManager()
+        filesystem_bound = isinstance(provider, DefaultProvider)
+
+        def loader(path):
+            if path is None:
+                return None, None
+
+            path = posixpath.join(package_path, path)
+
+            if not provider.has_resource(path):
+                return None, None
+
+            basename = posixpath.basename(path)
+
+            if filesystem_bound:
+                return (
+                    basename,
+                    self._opener(provider.get_resource_filename(manager, path)),
+                )
+
+            s = provider.get_resource_string(manager, path)
+            return basename, lambda: (BytesIO(s), loadtime, len(s))
+
+        return loader
+
+    def get_directory_loader(self, directory):
+        def loader(path):
+            if path is not None:
+                path = os.path.join(directory, path)
+            else:
+                path = directory
+
+            if os.path.isfile(path):
+                return os.path.basename(path), self._opener(path)
+
+            return None, None
+
+        return loader
+
+    def generate_etag(self, mtime, file_size, real_filename):
+        if not isinstance(real_filename, bytes):
+            real_filename = real_filename.encode(get_filesystem_encoding())
+
+        return "wzsdm-%d-%s-%s" % (
+            mktime(mtime.timetuple()),
+            file_size,
+            adler32(real_filename) & 0xFFFFFFFF,
+        )
+
+    def __call__(self, environ, start_response):
+        cleaned_path = get_path_info(environ)
+
+        if PY2:
+            cleaned_path = cleaned_path.encode(get_filesystem_encoding())
+
+        # sanitize the path for non unix systems
+        cleaned_path = cleaned_path.strip("/")
+
+        for sep in os.sep, os.altsep:
+            if sep and sep != "/":
+                cleaned_path = cleaned_path.replace(sep, "/")
+
+        path = "/" + "/".join(x for x in cleaned_path.split("/") if x and x != "..")
+        file_loader = None
+
+        for search_path, loader in self.exports:
+            if search_path == path:
+                real_filename, file_loader = loader(None)
+
+                if file_loader is not None:
+                    break
+
+            if not search_path.endswith("/"):
+                search_path += "/"
+
+            if path.startswith(search_path):
+                real_filename, file_loader = loader(path[len(search_path) :])
+
+                if file_loader is not None:
+                    break
+
+        if file_loader is None or not self.is_allowed(real_filename):
+            return self.app(environ, start_response)
+
+        guessed_type = mimetypes.guess_type(real_filename)
+        mime_type = guessed_type[0] or self.fallback_mimetype
+        f, mtime, file_size = file_loader()
+
+        headers = [("Date", http_date())]
+
+        if self.cache:
+            timeout = self.cache_timeout
+            etag = self.generate_etag(mtime, file_size, real_filename)
+            headers += [
+                ("Etag", '"%s"' % etag),
+                ("Cache-Control", "max-age=%d, public" % timeout),
+            ]
+
+            if not is_resource_modified(environ, etag, last_modified=mtime):
+                f.close()
+                start_response("304 Not Modified", headers)
+                return []
+
+            headers.append(("Expires", http_date(time() + timeout)))
+        else:
+            headers.append(("Cache-Control", "public"))
+
+        headers.extend(
+            (
+                ("Content-Type", mime_type),
+                ("Content-Length", str(file_size)),
+                ("Last-Modified", http_date(mtime)),
+            )
+        )
+        start_response("200 OK", headers)
+        return wrap_file(environ, f)
diff --git a/python/werkzeug/posixemulation.py b/python/werkzeug/posixemulation.py
new file mode 100644
index 0000000..696b456
--- /dev/null
+++ b/python/werkzeug/posixemulation.py
@@ -0,0 +1,117 @@
+# -*- coding: utf-8 -*-
+r"""
+    werkzeug.posixemulation
+    ~~~~~~~~~~~~~~~~~~~~~~~
+
+    Provides a POSIX emulation for some features that are relevant to
+    web applications.  The main purpose is to simplify support for
+    systems such as Windows NT that are not 100% POSIX compatible.
+
+    Currently this only implements a :func:`rename` function that
+    follows POSIX semantics.  Eg: if the target file already exists it
+    will be replaced without asking.
+
+    This module was introduced in 0.6.1 and is not a public interface.
+    It might become one in later versions of Werkzeug.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import errno
+import os
+import random
+import sys
+import time
+
+from ._compat import to_unicode
+from .filesystem import get_filesystem_encoding
+
+can_rename_open_file = False
+
+if os.name == "nt":
+    try:
+        import ctypes
+
+        _MOVEFILE_REPLACE_EXISTING = 0x1
+        _MOVEFILE_WRITE_THROUGH = 0x8
+        _MoveFileEx = ctypes.windll.kernel32.MoveFileExW
+
+        def _rename(src, dst):
+            src = to_unicode(src, get_filesystem_encoding())
+            dst = to_unicode(dst, get_filesystem_encoding())
+            if _rename_atomic(src, dst):
+                return True
+            retry = 0
+            rv = False
+            while not rv and retry < 100:
+                rv = _MoveFileEx(
+                    src, dst, _MOVEFILE_REPLACE_EXISTING | _MOVEFILE_WRITE_THROUGH
+                )
+                if not rv:
+                    time.sleep(0.001)
+                    retry += 1
+            return rv
+
+        # new in Vista and Windows Server 2008
+        _CreateTransaction = ctypes.windll.ktmw32.CreateTransaction
+        _CommitTransaction = ctypes.windll.ktmw32.CommitTransaction
+        _MoveFileTransacted = ctypes.windll.kernel32.MoveFileTransactedW
+        _CloseHandle = ctypes.windll.kernel32.CloseHandle
+        can_rename_open_file = True
+
+        def _rename_atomic(src, dst):
+            ta = _CreateTransaction(None, 0, 0, 0, 0, 1000, "Werkzeug rename")
+            if ta == -1:
+                return False
+            try:
+                retry = 0
+                rv = False
+                while not rv and retry < 100:
+                    rv = _MoveFileTransacted(
+                        src,
+                        dst,
+                        None,
+                        None,
+                        _MOVEFILE_REPLACE_EXISTING | _MOVEFILE_WRITE_THROUGH,
+                        ta,
+                    )
+                    if rv:
+                        rv = _CommitTransaction(ta)
+                        break
+                    else:
+                        time.sleep(0.001)
+                        retry += 1
+                return rv
+            finally:
+                _CloseHandle(ta)
+
+    except Exception:
+
+        def _rename(src, dst):
+            return False
+
+        def _rename_atomic(src, dst):
+            return False
+
+    def rename(src, dst):
+        # Try atomic or pseudo-atomic rename
+        if _rename(src, dst):
+            return
+        # Fall back to "move away and replace"
+        try:
+            os.rename(src, dst)
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
+            old = "%s-%08x" % (dst, random.randint(0, sys.maxsize))
+            os.rename(dst, old)
+            os.rename(src, dst)
+            try:
+                os.unlink(old)
+            except Exception:
+                pass
+
+
+else:
+    rename = os.rename
+    can_rename_open_file = True
diff --git a/python/werkzeug/routing.py b/python/werkzeug/routing.py
new file mode 100644
index 0000000..6b1dd98
--- /dev/null
+++ b/python/werkzeug/routing.py
@@ -0,0 +1,2026 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.routing
+    ~~~~~~~~~~~~~~~~
+
+    When it comes to combining multiple controller or view functions (however
+    you want to call them) you need a dispatcher.  A simple way would be
+    applying regular expression tests on the ``PATH_INFO`` and calling
+    registered callback functions that return the value then.
+
+    This module implements a much more powerful system than simple regular
+    expression matching because it can also convert values in the URLs and
+    build URLs.
+
+    Here a simple example that creates an URL map for an application with
+    two subdomains (www and kb) and some URL rules:
+
+    >>> m = Map([
+    ...     # Static URLs
+    ...     Rule('/', endpoint='static/index'),
+    ...     Rule('/about', endpoint='static/about'),
+    ...     Rule('/help', endpoint='static/help'),
+    ...     # Knowledge Base
+    ...     Subdomain('kb', [
+    ...         Rule('/', endpoint='kb/index'),
+    ...         Rule('/browse/', endpoint='kb/browse'),
+    ...         Rule('/browse/<int:id>/', endpoint='kb/browse'),
+    ...         Rule('/browse/<int:id>/<int:page>', endpoint='kb/browse')
+    ...     ])
+    ... ], default_subdomain='www')
+
+    If the application doesn't use subdomains it's perfectly fine to not set
+    the default subdomain and not use the `Subdomain` rule factory.  The endpoint
+    in the rules can be anything, for example import paths or unique
+    identifiers.  The WSGI application can use those endpoints to get the
+    handler for that URL.  It doesn't have to be a string at all but it's
+    recommended.
+
+    Now it's possible to create a URL adapter for one of the subdomains and
+    build URLs:
+
+    >>> c = m.bind('example.com')
+    >>> c.build("kb/browse", dict(id=42))
+    'http://kb.example.com/browse/42/'
+    >>> c.build("kb/browse", dict())
+    'http://kb.example.com/browse/'
+    >>> c.build("kb/browse", dict(id=42, page=3))
+    'http://kb.example.com/browse/42/3'
+    >>> c.build("static/about")
+    '/about'
+    >>> c.build("static/index", force_external=True)
+    'http://www.example.com/'
+
+    >>> c = m.bind('example.com', subdomain='kb')
+    >>> c.build("static/about")
+    'http://www.example.com/about'
+
+    The first argument to bind is the server name *without* the subdomain.
+    Per default it will assume that the script is mounted on the root, but
+    often that's not the case so you can provide the real mount point as
+    second argument:
+
+    >>> c = m.bind('example.com', '/applications/example')
+
+    The third argument can be the subdomain, if not given the default
+    subdomain is used.  For more details about binding have a look at the
+    documentation of the `MapAdapter`.
+
+    And here is how you can match URLs:
+
+    >>> c = m.bind('example.com')
+    >>> c.match("/")
+    ('static/index', {})
+    >>> c.match("/about")
+    ('static/about', {})
+    >>> c = m.bind('example.com', '/', 'kb')
+    >>> c.match("/")
+    ('kb/index', {})
+    >>> c.match("/browse/42/23")
+    ('kb/browse', {'id': 42, 'page': 23})
+
+    If matching fails you get a `NotFound` exception, if the rule thinks
+    it's a good idea to redirect (for example because the URL was defined
+    to have a slash at the end but the request was missing that slash) it
+    will raise a `RequestRedirect` exception.  Both are subclasses of the
+    `HTTPException` so you can use those errors as responses in the
+    application.
+
+    If matching succeeded but the URL rule was incompatible to the given
+    method (for example there were only rules for `GET` and `HEAD` and
+    routing system tried to match a `POST` request) a `MethodNotAllowed`
+    exception is raised.
+
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import ast
+import difflib
+import posixpath
+import re
+import uuid
+from pprint import pformat
+from threading import Lock
+
+from ._compat import implements_to_string
+from ._compat import iteritems
+from ._compat import itervalues
+from ._compat import native_string_result
+from ._compat import string_types
+from ._compat import text_type
+from ._compat import to_bytes
+from ._compat import to_unicode
+from ._compat import wsgi_decoding_dance
+from ._internal import _encode_idna
+from ._internal import _get_environ
+from .datastructures import ImmutableDict
+from .datastructures import MultiDict
+from .exceptions import BadHost
+from .exceptions import HTTPException
+from .exceptions import MethodNotAllowed
+from .exceptions import NotFound
+from .urls import _fast_url_quote
+from .urls import url_encode
+from .urls import url_join
+from .urls import url_quote
+from .utils import cached_property
+from .utils import format_string
+from .utils import redirect
+from .wsgi import get_host
+
+_rule_re = re.compile(
+    r"""
+    (?P<static>[^<]*)                           # static rule data
+    <
+    (?:
+        (?P<converter>[a-zA-Z_][a-zA-Z0-9_]*)   # converter name
+        (?:\((?P<args>.*?)\))?                  # converter arguments
+        \:                                      # variable delimiter
+    )?
+    (?P<variable>[a-zA-Z_][a-zA-Z0-9_]*)        # variable name
+    >
+    """,
+    re.VERBOSE,
+)
+_simple_rule_re = re.compile(r"<([^>]+)>")
+_converter_args_re = re.compile(
+    r"""
+    ((?P<name>\w+)\s*=\s*)?
+    (?P<value>
+        True|False|
+        \d+.\d+|
+        \d+.|
+        \d+|
+        [\w\d_.]+|
+        [urUR]?(?P<stringval>"[^"]*?"|'[^']*')
+    )\s*,
+    """,
+    re.VERBOSE | re.UNICODE,
+)
+
+
+_PYTHON_CONSTANTS = {"None": None, "True": True, "False": False}
+
+
+def _pythonize(value):
+    if value in _PYTHON_CONSTANTS:
+        return _PYTHON_CONSTANTS[value]
+    for convert in int, float:
+        try:
+            return convert(value)
+        except ValueError:
+            pass
+    if value[:1] == value[-1:] and value[0] in "\"'":
+        value = value[1:-1]
+    return text_type(value)
+
+
+def parse_converter_args(argstr):
+    argstr += ","
+    args = []
+    kwargs = {}
+
+    for item in _converter_args_re.finditer(argstr):
+        value = item.group("stringval")
+        if value is None:
+            value = item.group("value")
+        value = _pythonize(value)
+        if not item.group("name"):
+            args.append(value)
+        else:
+            name = item.group("name")
+            kwargs[name] = value
+
+    return tuple(args), kwargs
+
+
+def parse_rule(rule):
+    """Parse a rule and return it as generator. Each iteration yields tuples
+    in the form ``(converter, arguments, variable)``. If the converter is
+    `None` it's a static url part, otherwise it's a dynamic one.
+
+    :internal:
+    """
+    pos = 0
+    end = len(rule)
+    do_match = _rule_re.match
+    used_names = set()
+    while pos < end:
+        m = do_match(rule, pos)
+        if m is None:
+            break
+        data = m.groupdict()
+        if data["static"]:
+            yield None, None, data["static"]
+        variable = data["variable"]
+        converter = data["converter"] or "default"
+        if variable in used_names:
+            raise ValueError("variable name %r used twice." % variable)
+        used_names.add(variable)
+        yield converter, data["args"] or None, variable
+        pos = m.end()
+    if pos < end:
+        remaining = rule[pos:]
+        if ">" in remaining or "<" in remaining:
+            raise ValueError("malformed url rule: %r" % rule)
+        yield None, None, remaining
+
+
+class RoutingException(Exception):
+    """Special exceptions that require the application to redirect, notifying
+    about missing urls, etc.
+
+    :internal:
+    """
+
+
+class RequestRedirect(HTTPException, RoutingException):
+    """Raise if the map requests a redirect. This is for example the case if
+    `strict_slashes` are activated and an url that requires a trailing slash.
+
+    The attribute `new_url` contains the absolute destination url.
+    """
+
+    code = 308
+
+    def __init__(self, new_url):
+        RoutingException.__init__(self, new_url)
+        self.new_url = new_url
+
+    def get_response(self, environ):
+        return redirect(self.new_url, self.code)
+
+
+class RequestSlash(RoutingException):
+    """Internal exception."""
+
+
+class RequestAliasRedirect(RoutingException):  # noqa: B903
+    """This rule is an alias and wants to redirect to the canonical URL."""
+
+    def __init__(self, matched_values):
+        self.matched_values = matched_values
+
+
+@implements_to_string
+class BuildError(RoutingException, LookupError):
+    """Raised if the build system cannot find a URL for an endpoint with the
+    values provided.
+    """
+
+    def __init__(self, endpoint, values, method, adapter=None):
+        LookupError.__init__(self, endpoint, values, method)
+        self.endpoint = endpoint
+        self.values = values
+        self.method = method
+        self.adapter = adapter
+
+    @cached_property
+    def suggested(self):
+        return self.closest_rule(self.adapter)
+
+    def closest_rule(self, adapter):
+        def _score_rule(rule):
+            return sum(
+                [
+                    0.98
+                    * difflib.SequenceMatcher(
+                        None, rule.endpoint, self.endpoint
+                    ).ratio(),
+                    0.01 * bool(set(self.values or ()).issubset(rule.arguments)),
+                    0.01 * bool(rule.methods and self.method in rule.methods),
+                ]
+            )
+
+        if adapter and adapter.map._rules:
+            return max(adapter.map._rules, key=_score_rule)
+
+    def __str__(self):
+        message = []
+        message.append("Could not build url for endpoint %r" % self.endpoint)
+        if self.method:
+            message.append(" (%r)" % self.method)
+        if self.values:
+            message.append(" with values %r" % sorted(self.values.keys()))
+        message.append(".")
+        if self.suggested:
+            if self.endpoint == self.suggested.endpoint:
+                if self.method and self.method not in self.suggested.methods:
+                    message.append(
+                        " Did you mean to use methods %r?"
+                        % sorted(self.suggested.methods)
+                    )
+                missing_values = self.suggested.arguments.union(
+                    set(self.suggested.defaults or ())
+                ) - set(self.values.keys())
+                if missing_values:
+                    message.append(
+                        " Did you forget to specify values %r?" % sorted(missing_values)
+                    )
+            else:
+                message.append(" Did you mean %r instead?" % self.suggested.endpoint)
+        return u"".join(message)
+
+
+class ValidationError(ValueError):
+    """Validation error.  If a rule converter raises this exception the rule
+    does not match the current URL and the next URL is tried.
+    """
+
+
+class RuleFactory(object):
+    """As soon as you have more complex URL setups it's a good idea to use rule
+    factories to avoid repetitive tasks.  Some of them are builtin, others can
+    be added by subclassing `RuleFactory` and overriding `get_rules`.
+    """
+
+    def get_rules(self, map):
+        """Subclasses of `RuleFactory` have to override this method and return
+        an iterable of rules."""
+        raise NotImplementedError()
+
+
+class Subdomain(RuleFactory):
+    """All URLs provided by this factory have the subdomain set to a
+    specific domain. For example if you want to use the subdomain for
+    the current language this can be a good setup::
+
+        url_map = Map([
+            Rule('/', endpoint='#select_language'),
+            Subdomain('<string(length=2):lang_code>', [
+                Rule('/', endpoint='index'),
+                Rule('/about', endpoint='about'),
+                Rule('/help', endpoint='help')
+            ])
+        ])
+
+    All the rules except for the ``'#select_language'`` endpoint will now
+    listen on a two letter long subdomain that holds the language code
+    for the current request.
+    """
+
+    def __init__(self, subdomain, rules):
+        self.subdomain = subdomain
+        self.rules = rules
+
+    def get_rules(self, map):
+        for rulefactory in self.rules:
+            for rule in rulefactory.get_rules(map):
+                rule = rule.empty()
+                rule.subdomain = self.subdomain
+                yield rule
+
+
+class Submount(RuleFactory):
+    """Like `Subdomain` but prefixes the URL rule with a given string::
+
+        url_map = Map([
+            Rule('/', endpoint='index'),
+            Submount('/blog', [
+                Rule('/', endpoint='blog/index'),
+                Rule('/entry/<entry_slug>', endpoint='blog/show')
+            ])
+        ])
+
+    Now the rule ``'blog/show'`` matches ``/blog/entry/<entry_slug>``.
+    """
+
+    def __init__(self, path, rules):
+        self.path = path.rstrip("/")
+        self.rules = rules
+
+    def get_rules(self, map):
+        for rulefactory in self.rules:
+            for rule in rulefactory.get_rules(map):
+                rule = rule.empty()
+                rule.rule = self.path + rule.rule
+                yield rule
+
+
+class EndpointPrefix(RuleFactory):
+    """Prefixes all endpoints (which must be strings for this factory) with
+    another string. This can be useful for sub applications::
+
+        url_map = Map([
+            Rule('/', endpoint='index'),
+            EndpointPrefix('blog/', [Submount('/blog', [
+                Rule('/', endpoint='index'),
+                Rule('/entry/<entry_slug>', endpoint='show')
+            ])])
+        ])
+    """
+
+    def __init__(self, prefix, rules):
+        self.prefix = prefix
+        self.rules = rules
+
+    def get_rules(self, map):
+        for rulefactory in self.rules:
+            for rule in rulefactory.get_rules(map):
+                rule = rule.empty()
+                rule.endpoint = self.prefix + rule.endpoint
+                yield rule
+
+
+class RuleTemplate(object):
+    """Returns copies of the rules wrapped and expands string templates in
+    the endpoint, rule, defaults or subdomain sections.
+
+    Here a small example for such a rule template::
+
+        from werkzeug.routing import Map, Rule, RuleTemplate
+
+        resource = RuleTemplate([
+            Rule('/$name/', endpoint='$name.list'),
+            Rule('/$name/<int:id>', endpoint='$name.show')
+        ])
+
+        url_map = Map([resource(name='user'), resource(name='page')])
+
+    When a rule template is called the keyword arguments are used to
+    replace the placeholders in all the string parameters.
+    """
+
+    def __init__(self, rules):
+        self.rules = list(rules)
+
+    def __call__(self, *args, **kwargs):
+        return RuleTemplateFactory(self.rules, dict(*args, **kwargs))
+
+
+class RuleTemplateFactory(RuleFactory):
+    """A factory that fills in template variables into rules.  Used by
+    `RuleTemplate` internally.
+
+    :internal:
+    """
+
+    def __init__(self, rules, context):
+        self.rules = rules
+        self.context = context
+
+    def get_rules(self, map):
+        for rulefactory in self.rules:
+            for rule in rulefactory.get_rules(map):
+                new_defaults = subdomain = None
+                if rule.defaults:
+                    new_defaults = {}
+                    for key, value in iteritems(rule.defaults):
+                        if isinstance(value, string_types):
+                            value = format_string(value, self.context)
+                        new_defaults[key] = value
+                if rule.subdomain is not None:
+                    subdomain = format_string(rule.subdomain, self.context)
+                new_endpoint = rule.endpoint
+                if isinstance(new_endpoint, string_types):
+                    new_endpoint = format_string(new_endpoint, self.context)
+                yield Rule(
+                    format_string(rule.rule, self.context),
+                    new_defaults,
+                    subdomain,
+                    rule.methods,
+                    rule.build_only,
+                    new_endpoint,
+                    rule.strict_slashes,
+                )
+
+
+def _prefix_names(src):
+    """ast parse and prefix names with `.` to avoid collision with user vars"""
+    tree = ast.parse(src).body[0]
+    if isinstance(tree, ast.Expr):
+        tree = tree.value
+    for node in ast.walk(tree):
+        if isinstance(node, ast.Name):
+            node.id = "." + node.id
+    return tree
+
+
+_CALL_CONVERTER_CODE_FMT = "self._converters[{elem!r}].to_url()"
+_IF_KWARGS_URL_ENCODE_CODE = """\
+if kwargs:
+    q = '?'
+    params = self._encode_query_vars(kwargs)
+else:
+    q = params = ''
+"""
+_IF_KWARGS_URL_ENCODE_AST = _prefix_names(_IF_KWARGS_URL_ENCODE_CODE)
+_URL_ENCODE_AST_NAMES = (_prefix_names("q"), _prefix_names("params"))
+
+
+@implements_to_string
+class Rule(RuleFactory):
+    """A Rule represents one URL pattern.  There are some options for `Rule`
+    that change the way it behaves and are passed to the `Rule` constructor.
+    Note that besides the rule-string all arguments *must* be keyword arguments
+    in order to not break the application on Werkzeug upgrades.
+
+    `string`
+        Rule strings basically are just normal URL paths with placeholders in
+        the format ``<converter(arguments):name>`` where the converter and the
+        arguments are optional.  If no converter is defined the `default`
+        converter is used which means `string` in the normal configuration.
+
+        URL rules that end with a slash are branch URLs, others are leaves.
+        If you have `strict_slashes` enabled (which is the default), all
+        branch URLs that are matched without a trailing slash will trigger a
+        redirect to the same URL with the missing slash appended.
+
+        The converters are defined on the `Map`.
+
+    `endpoint`
+        The endpoint for this rule. This can be anything. A reference to a
+        function, a string, a number etc.  The preferred way is using a string
+        because the endpoint is used for URL generation.
+
+    `defaults`
+        An optional dict with defaults for other rules with the same endpoint.
+        This is a bit tricky but useful if you want to have unique URLs::
+
+            url_map = Map([
+                Rule('/all/', defaults={'page': 1}, endpoint='all_entries'),
+                Rule('/all/page/<int:page>', endpoint='all_entries')
+            ])
+
+        If a user now visits ``http://example.com/all/page/1`` he will be
+        redirected to ``http://example.com/all/``.  If `redirect_defaults` is
+        disabled on the `Map` instance this will only affect the URL
+        generation.
+
+    `subdomain`
+        The subdomain rule string for this rule. If not specified the rule
+        only matches for the `default_subdomain` of the map.  If the map is
+        not bound to a subdomain this feature is disabled.
+
+        Can be useful if you want to have user profiles on different subdomains
+        and all subdomains are forwarded to your application::
+
+            url_map = Map([
+                Rule('/', subdomain='<username>', endpoint='user/homepage'),
+                Rule('/stats', subdomain='<username>', endpoint='user/stats')
+            ])
+
+    `methods`
+        A sequence of http methods this rule applies to.  If not specified, all
+        methods are allowed. For example this can be useful if you want different
+        endpoints for `POST` and `GET`.  If methods are defined and the path
+        matches but the method matched against is not in this list or in the
+        list of another rule for that path the error raised is of the type
+        `MethodNotAllowed` rather than `NotFound`.  If `GET` is present in the
+        list of methods and `HEAD` is not, `HEAD` is added automatically.
+
+        .. versionchanged:: 0.6.1
+           `HEAD` is now automatically added to the methods if `GET` is
+           present.  The reason for this is that existing code often did not
+           work properly in servers not rewriting `HEAD` to `GET`
+           automatically and it was not documented how `HEAD` should be
+           treated.  This was considered a bug in Werkzeug because of that.
+
+    `strict_slashes`
+        Override the `Map` setting for `strict_slashes` only for this rule. If
+        not specified the `Map` setting is used.
+
+    `build_only`
+        Set this to True and the rule will never match but will create a URL
+        that can be build. This is useful if you have resources on a subdomain
+        or folder that are not handled by the WSGI application (like static data)
+
+    `redirect_to`
+        If given this must be either a string or callable.  In case of a
+        callable it's called with the url adapter that triggered the match and
+        the values of the URL as keyword arguments and has to return the target
+        for the redirect, otherwise it has to be a string with placeholders in
+        rule syntax::
+
+            def foo_with_slug(adapter, id):
+                # ask the database for the slug for the old id.  this of
+                # course has nothing to do with werkzeug.
+                return 'foo/' + Foo.get_slug_for_id(id)
+
+            url_map = Map([
+                Rule('/foo/<slug>', endpoint='foo'),
+                Rule('/some/old/url/<slug>', redirect_to='foo/<slug>'),
+                Rule('/other/old/url/<int:id>', redirect_to=foo_with_slug)
+            ])
+
+        When the rule is matched the routing system will raise a
+        `RequestRedirect` exception with the target for the redirect.
+
+        Keep in mind that the URL will be joined against the URL root of the
+        script so don't use a leading slash on the target URL unless you
+        really mean root of that domain.
+
+    `alias`
+        If enabled this rule serves as an alias for another rule with the same
+        endpoint and arguments.
+
+    `host`
+        If provided and the URL map has host matching enabled this can be
+        used to provide a match rule for the whole host.  This also means
+        that the subdomain feature is disabled.
+
+    .. versionadded:: 0.7
+       The `alias` and `host` parameters were added.
+    """
+
+    def __init__(
+        self,
+        string,
+        defaults=None,
+        subdomain=None,
+        methods=None,
+        build_only=False,
+        endpoint=None,
+        strict_slashes=None,
+        redirect_to=None,
+        alias=False,
+        host=None,
+    ):
+        if not string.startswith("/"):
+            raise ValueError("urls must start with a leading slash")
+        self.rule = string
+        self.is_leaf = not string.endswith("/")
+
+        self.map = None
+        self.strict_slashes = strict_slashes
+        self.subdomain = subdomain
+        self.host = host
+        self.defaults = defaults
+        self.build_only = build_only
+        self.alias = alias
+        if methods is None:
+            self.methods = None
+        else:
+            if isinstance(methods, str):
+                raise TypeError("param `methods` should be `Iterable[str]`, not `str`")
+            self.methods = set([x.upper() for x in methods])
+            if "HEAD" not in self.methods and "GET" in self.methods:
+                self.methods.add("HEAD")
+        self.endpoint = endpoint
+        self.redirect_to = redirect_to
+
+        if defaults:
+            self.arguments = set(map(str, defaults))
+        else:
+            self.arguments = set()
+        self._trace = self._converters = self._regex = self._argument_weights = None
+
+    def empty(self):
+        """
+        Return an unbound copy of this rule.
+
+        This can be useful if want to reuse an already bound URL for another
+        map.  See ``get_empty_kwargs`` to override what keyword arguments are
+        provided to the new copy.
+        """
+        return type(self)(self.rule, **self.get_empty_kwargs())
+
+    def get_empty_kwargs(self):
+        """
+        Provides kwargs for instantiating empty copy with empty()
+
+        Use this method to provide custom keyword arguments to the subclass of
+        ``Rule`` when calling ``some_rule.empty()``.  Helpful when the subclass
+        has custom keyword arguments that are needed at instantiation.
+
+        Must return a ``dict`` that will be provided as kwargs to the new
+        instance of ``Rule``, following the initial ``self.rule`` value which
+        is always provided as the first, required positional argument.
+        """
+        defaults = None
+        if self.defaults:
+            defaults = dict(self.defaults)
+        return dict(
+            defaults=defaults,
+            subdomain=self.subdomain,
+            methods=self.methods,
+            build_only=self.build_only,
+            endpoint=self.endpoint,
+            strict_slashes=self.strict_slashes,
+            redirect_to=self.redirect_to,
+            alias=self.alias,
+            host=self.host,
+        )
+
+    def get_rules(self, map):
+        yield self
+
+    def refresh(self):
+        """Rebinds and refreshes the URL.  Call this if you modified the
+        rule in place.
+
+        :internal:
+        """
+        self.bind(self.map, rebind=True)
+
+    def bind(self, map, rebind=False):
+        """Bind the url to a map and create a regular expression based on
+        the information from the rule itself and the defaults from the map.
+
+        :internal:
+        """
+        if self.map is not None and not rebind:
+            raise RuntimeError("url rule %r already bound to map %r" % (self, self.map))
+        self.map = map
+        if self.strict_slashes is None:
+            self.strict_slashes = map.strict_slashes
+        if self.subdomain is None:
+            self.subdomain = map.default_subdomain
+        self.compile()
+
+    def get_converter(self, variable_name, converter_name, args, kwargs):
+        """Looks up the converter for the given parameter.
+
+        .. versionadded:: 0.9
+        """
+        if converter_name not in self.map.converters:
+            raise LookupError("the converter %r does not exist" % converter_name)
+        return self.map.converters[converter_name](self.map, *args, **kwargs)
+
+    def _encode_query_vars(self, query_vars):
+        return url_encode(
+            query_vars,
+            charset=self.map.charset,
+            sort=self.map.sort_parameters,
+            key=self.map.sort_key,
+        )
+
+    def compile(self):
+        """Compiles the regular expression and stores it."""
+        assert self.map is not None, "rule not bound"
+
+        if self.map.host_matching:
+            domain_rule = self.host or ""
+        else:
+            domain_rule = self.subdomain or ""
+
+        self._trace = []
+        self._converters = {}
+        self._static_weights = []
+        self._argument_weights = []
+        regex_parts = []
+
+        def _build_regex(rule):
+            index = 0
+            for converter, arguments, variable in parse_rule(rule):
+                if converter is None:
+                    regex_parts.append(re.escape(variable))
+                    self._trace.append((False, variable))
+                    for part in variable.split("/"):
+                        if part:
+                            self._static_weights.append((index, -len(part)))
+                else:
+                    if arguments:
+                        c_args, c_kwargs = parse_converter_args(arguments)
+                    else:
+                        c_args = ()
+                        c_kwargs = {}
+                    convobj = self.get_converter(variable, converter, c_args, c_kwargs)
+                    regex_parts.append("(?P<%s>%s)" % (variable, convobj.regex))
+                    self._converters[variable] = convobj
+                    self._trace.append((True, variable))
+                    self._argument_weights.append(convobj.weight)
+                    self.arguments.add(str(variable))
+                index = index + 1
+
+        _build_regex(domain_rule)
+        regex_parts.append("\\|")
+        self._trace.append((False, "|"))
+        _build_regex(self.rule if self.is_leaf else self.rule.rstrip("/"))
+        if not self.is_leaf:
+            self._trace.append((False, "/"))
+
+        self._build = self._compile_builder(False).__get__(self, None)
+        self._build_unknown = self._compile_builder(True).__get__(self, None)
+
+        if self.build_only:
+            return
+        regex = r"^%s%s$" % (
+            u"".join(regex_parts),
+            (not self.is_leaf or not self.strict_slashes)
+            and "(?<!/)(?P<__suffix__>/?)"
+            or "",
+        )
+        self._regex = re.compile(regex, re.UNICODE)
+
+    def match(self, path, method=None):
+        """Check if the rule matches a given path. Path is a string in the
+        form ``"subdomain|/path"`` and is assembled by the map.  If
+        the map is doing host matching the subdomain part will be the host
+        instead.
+
+        If the rule matches a dict with the converted values is returned,
+        otherwise the return value is `None`.
+
+        :internal:
+        """
+        if not self.build_only:
+            m = self._regex.search(path)
+            if m is not None:
+                groups = m.groupdict()
+                # we have a folder like part of the url without a trailing
+                # slash and strict slashes enabled. raise an exception that
+                # tells the map to redirect to the same url but with a
+                # trailing slash
+                if (
+                    self.strict_slashes
+                    and not self.is_leaf
+                    and not groups.pop("__suffix__")
+                    and (
+                        method is None or self.methods is None or method in self.methods
+                    )
+                ):
+                    raise RequestSlash()
+                # if we are not in strict slashes mode we have to remove
+                # a __suffix__
+                elif not self.strict_slashes:
+                    del groups["__suffix__"]
+
+                result = {}
+                for name, value in iteritems(groups):
+                    try:
+                        value = self._converters[name].to_python(value)
+                    except ValidationError:
+                        return
+                    result[str(name)] = value
+                if self.defaults:
+                    result.update(self.defaults)
+
+                if self.alias and self.map.redirect_defaults:
+                    raise RequestAliasRedirect(result)
+
+                return result
+
+    @staticmethod
+    def _get_func_code(code, name):
+        globs, locs = {}, {}
+        exec(code, globs, locs)
+        return locs[name]
+
+    def _compile_builder(self, append_unknown=True):
+        defaults = self.defaults or {}
+        dom_ops = []
+        url_ops = []
+
+        opl = dom_ops
+        for is_dynamic, data in self._trace:
+            if data == "|" and opl is dom_ops:
+                opl = url_ops
+                continue
+            # this seems like a silly case to ever come up but:
+            # if a default is given for a value that appears in the rule,
+            # resolve it to a constant ahead of time
+            if is_dynamic and data in defaults:
+                data = self._converters[data].to_url(defaults[data])
+                opl.append((False, data))
+            elif not is_dynamic:
+                opl.append(
+                    (False, url_quote(to_bytes(data, self.map.charset), safe="/:|+"))
+                )
+            else:
+                opl.append((True, data))
+
+        def _convert(elem):
+            ret = _prefix_names(_CALL_CONVERTER_CODE_FMT.format(elem=elem))
+            ret.args = [ast.Name(str(elem), ast.Load())]  # str for py2
+            return ret
+
+        def _parts(ops):
+            parts = [
+                _convert(elem) if is_dynamic else ast.Str(s=elem)
+                for is_dynamic, elem in ops
+            ]
+            parts = parts or [ast.Str("")]
+            # constant fold
+            ret = [parts[0]]
+            for p in parts[1:]:
+                if isinstance(p, ast.Str) and isinstance(ret[-1], ast.Str):
+                    ret[-1] = ast.Str(ret[-1].s + p.s)
+                else:
+                    ret.append(p)
+            return ret
+
+        dom_parts = _parts(dom_ops)
+        url_parts = _parts(url_ops)
+        if not append_unknown:
+            body = []
+        else:
+            body = [_IF_KWARGS_URL_ENCODE_AST]
+            url_parts.extend(_URL_ENCODE_AST_NAMES)
+
+        def _join(parts):
+            if len(parts) == 1:  # shortcut
+                return parts[0]
+            elif hasattr(ast, "JoinedStr"):  # py36+
+                return ast.JoinedStr(parts)
+            else:
+                call = _prefix_names('"".join()')
+                call.args = [ast.Tuple(parts, ast.Load())]
+                return call
+
+        body.append(
+            ast.Return(ast.Tuple([_join(dom_parts), _join(url_parts)], ast.Load()))
+        )
+
+        # str is necessary for python2
+        pargs = [
+            str(elem)
+            for is_dynamic, elem in dom_ops + url_ops
+            if is_dynamic and elem not in defaults
+        ]
+        kargs = [str(k) for k in defaults]
+
+        func_ast = _prefix_names("def _(): pass")
+        func_ast.name = "<builder:{!r}>".format(self.rule)
+        if hasattr(ast, "arg"):  # py3
+            func_ast.args.args.append(ast.arg(".self", None))
+            for arg in pargs + kargs:
+                func_ast.args.args.append(ast.arg(arg, None))
+            func_ast.args.kwarg = ast.arg(".kwargs", None)
+        else:
+            func_ast.args.args.append(ast.Name(".self", ast.Load()))
+            for arg in pargs + kargs:
+                func_ast.args.args.append(ast.Name(arg, ast.Load()))
+            func_ast.args.kwarg = ".kwargs"
+        for _ in kargs:
+            func_ast.args.defaults.append(ast.Str(""))
+        func_ast.body = body
+
+        module = ast.fix_missing_locations(ast.Module([func_ast]))
+        code = compile(module, "<werkzeug routing>", "exec")
+        return self._get_func_code(code, func_ast.name)
+
+    def build(self, values, append_unknown=True):
+        """Assembles the relative url for that rule and the subdomain.
+        If building doesn't work for some reasons `None` is returned.
+
+        :internal:
+        """
+        try:
+            if append_unknown:
+                return self._build_unknown(**values)
+            else:
+                return self._build(**values)
+        except ValidationError:
+            return None
+
+    def provides_defaults_for(self, rule):
+        """Check if this rule has defaults for a given rule.
+
+        :internal:
+        """
+        return (
+            not self.build_only
+            and self.defaults
+            and self.endpoint == rule.endpoint
+            and self != rule
+            and self.arguments == rule.arguments
+        )
+
+    def suitable_for(self, values, method=None):
+        """Check if the dict of values has enough data for url generation.
+
+        :internal:
+        """
+        # if a method was given explicitly and that method is not supported
+        # by this rule, this rule is not suitable.
+        if (
+            method is not None
+            and self.methods is not None
+            and method not in self.methods
+        ):
+            return False
+
+        defaults = self.defaults or ()
+
+        # all arguments required must be either in the defaults dict or
+        # the value dictionary otherwise it's not suitable
+        for key in self.arguments:
+            if key not in defaults and key not in values:
+                return False
+
+        # in case defaults are given we ensure that either the value was
+        # skipped or the value is the same as the default value.
+        if defaults:
+            for key, value in iteritems(defaults):
+                if key in values and value != values[key]:
+                    return False
+
+        return True
+
+    def match_compare_key(self):
+        """The match compare key for sorting.
+
+        Current implementation:
+
+        1.  rules without any arguments come first for performance
+            reasons only as we expect them to match faster and some
+            common ones usually don't have any arguments (index pages etc.)
+        2.  rules with more static parts come first so the second argument
+            is the negative length of the number of the static weights.
+        3.  we order by static weights, which is a combination of index
+            and length
+        4.  The more complex rules come first so the next argument is the
+            negative length of the number of argument weights.
+        5.  lastly we order by the actual argument weights.
+
+        :internal:
+        """
+        return (
+            bool(self.arguments),
+            -len(self._static_weights),
+            self._static_weights,
+            -len(self._argument_weights),
+            self._argument_weights,
+        )
+
+    def build_compare_key(self):
+        """The build compare key for sorting.
+
+        :internal:
+        """
+        return 1 if self.alias else 0, -len(self.arguments), -len(self.defaults or ())
+
+    def __eq__(self, other):
+        return self.__class__ is other.__class__ and self._trace == other._trace
+
+    __hash__ = None
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __str__(self):
+        return self.rule
+
+    @native_string_result
+    def __repr__(self):
+        if self.map is None:
+            return u"<%s (unbound)>" % self.__class__.__name__
+        tmp = []
+        for is_dynamic, data in self._trace:
+            if is_dynamic:
+                tmp.append(u"<%s>" % data)
+            else:
+                tmp.append(data)
+        return u"<%s %s%s -> %s>" % (
+            self.__class__.__name__,
+            repr((u"".join(tmp)).lstrip(u"|")).lstrip(u"u"),
+            self.methods is not None and u" (%s)" % u", ".join(self.methods) or u"",
+            self.endpoint,
+        )
+
+
+class BaseConverter(object):
+    """Base class for all converters."""
+
+    regex = "[^/]+"
+    weight = 100
+
+    def __init__(self, map):
+        self.map = map
+
+    def to_python(self, value):
+        return value
+
+    def to_url(self, value):
+        if isinstance(value, (bytes, bytearray)):
+            return _fast_url_quote(value)
+        return _fast_url_quote(text_type(value).encode(self.map.charset))
+
+
+class UnicodeConverter(BaseConverter):
+    """This converter is the default converter and accepts any string but
+    only one path segment.  Thus the string can not include a slash.
+
+    This is the default validator.
+
+    Example::
+
+        Rule('/pages/<page>'),
+        Rule('/<string(length=2):lang_code>')
+
+    :param map: the :class:`Map`.
+    :param minlength: the minimum length of the string.  Must be greater
+                      or equal 1.
+    :param maxlength: the maximum length of the string.
+    :param length: the exact length of the string.
+    """
+
+    def __init__(self, map, minlength=1, maxlength=None, length=None):
+        BaseConverter.__init__(self, map)
+        if length is not None:
+            length = "{%d}" % int(length)
+        else:
+            if maxlength is None:
+                maxlength = ""
+            else:
+                maxlength = int(maxlength)
+            length = "{%s,%s}" % (int(minlength), maxlength)
+        self.regex = "[^/]" + length
+
+
+class AnyConverter(BaseConverter):
+    """Matches one of the items provided.  Items can either be Python
+    identifiers or strings::
+
+        Rule('/<any(about, help, imprint, class, "foo,bar"):page_name>')
+
+    :param map: the :class:`Map`.
+    :param items: this function accepts the possible items as positional
+                  arguments.
+    """
+
+    def __init__(self, map, *items):
+        BaseConverter.__init__(self, map)
+        self.regex = "(?:%s)" % "|".join([re.escape(x) for x in items])
+
+
+class PathConverter(BaseConverter):
+    """Like the default :class:`UnicodeConverter`, but it also matches
+    slashes.  This is useful for wikis and similar applications::
+
+        Rule('/<path:wikipage>')
+        Rule('/<path:wikipage>/edit')
+
+    :param map: the :class:`Map`.
+    """
+
+    regex = "[^/].*?"
+    weight = 200
+
+
+class NumberConverter(BaseConverter):
+    """Baseclass for `IntegerConverter` and `FloatConverter`.
+
+    :internal:
+    """
+
+    weight = 50
+
+    def __init__(self, map, fixed_digits=0, min=None, max=None, signed=False):
+        if signed:
+            self.regex = self.signed_regex
+        BaseConverter.__init__(self, map)
+        self.fixed_digits = fixed_digits
+        self.min = min
+        self.max = max
+        self.signed = signed
+
+    def to_python(self, value):
+        if self.fixed_digits and len(value) != self.fixed_digits:
+            raise ValidationError()
+        value = self.num_convert(value)
+        if (self.min is not None and value < self.min) or (
+            self.max is not None and value > self.max
+        ):
+            raise ValidationError()
+        return value
+
+    def to_url(self, value):
+        value = self.num_convert(value)
+        if self.fixed_digits:
+            value = ("%%0%sd" % self.fixed_digits) % value
+        return str(value)
+
+    @property
+    def signed_regex(self):
+        return r"-?" + self.regex
+
+
+class IntegerConverter(NumberConverter):
+    """This converter only accepts integer values::
+
+        Rule("/page/<int:page>")
+
+    By default it only accepts unsigned, positive values. The ``signed``
+    parameter will enable signed, negative values. ::
+
+        Rule("/page/<int(signed=True):page>")
+
+    :param map: The :class:`Map`.
+    :param fixed_digits: The number of fixed digits in the URL. If you
+        set this to ``4`` for example, the rule will only match if the
+        URL looks like ``/0001/``. The default is variable length.
+    :param min: The minimal value.
+    :param max: The maximal value.
+    :param signed: Allow signed (negative) values.
+
+    .. versionadded:: 0.15
+        The ``signed`` parameter.
+    """
+
+    regex = r"\d+"
+    num_convert = int
+
+
+class FloatConverter(NumberConverter):
+    """This converter only accepts floating point values::
+
+        Rule("/probability/<float:probability>")
+
+    By default it only accepts unsigned, positive values. The ``signed``
+    parameter will enable signed, negative values. ::
+
+        Rule("/offset/<float(signed=True):offset>")
+
+    :param map: The :class:`Map`.
+    :param min: The minimal value.
+    :param max: The maximal value.
+    :param signed: Allow signed (negative) values.
+
+    .. versionadded:: 0.15
+        The ``signed`` parameter.
+    """
+
+    regex = r"\d+\.\d+"
+    num_convert = float
+
+    def __init__(self, map, min=None, max=None, signed=False):
+        NumberConverter.__init__(self, map, min=min, max=max, signed=signed)
+
+
+class UUIDConverter(BaseConverter):
+    """This converter only accepts UUID strings::
+
+        Rule('/object/<uuid:identifier>')
+
+    .. versionadded:: 0.10
+
+    :param map: the :class:`Map`.
+    """
+
+    regex = (
+        r"[A-Fa-f0-9]{8}-[A-Fa-f0-9]{4}-"
+        r"[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}"
+    )
+
+    def to_python(self, value):
+        return uuid.UUID(value)
+
+    def to_url(self, value):
+        return str(value)
+
+
+#: the default converter mapping for the map.
+DEFAULT_CONVERTERS = {
+    "default": UnicodeConverter,
+    "string": UnicodeConverter,
+    "any": AnyConverter,
+    "path": PathConverter,
+    "int": IntegerConverter,
+    "float": FloatConverter,
+    "uuid": UUIDConverter,
+}
+
+
+class Map(object):
+    """The map class stores all the URL rules and some configuration
+    parameters.  Some of the configuration values are only stored on the
+    `Map` instance since those affect all rules, others are just defaults
+    and can be overridden for each rule.  Note that you have to specify all
+    arguments besides the `rules` as keyword arguments!
+
+    :param rules: sequence of url rules for this map.
+    :param default_subdomain: The default subdomain for rules without a
+                              subdomain defined.
+    :param charset: charset of the url. defaults to ``"utf-8"``
+    :param strict_slashes: Take care of trailing slashes.
+    :param redirect_defaults: This will redirect to the default rule if it
+                              wasn't visited that way. This helps creating
+                              unique URLs.
+    :param converters: A dict of converters that adds additional converters
+                       to the list of converters. If you redefine one
+                       converter this will override the original one.
+    :param sort_parameters: If set to `True` the url parameters are sorted.
+                            See `url_encode` for more details.
+    :param sort_key: The sort key function for `url_encode`.
+    :param encoding_errors: the error method to use for decoding
+    :param host_matching: if set to `True` it enables the host matching
+                          feature and disables the subdomain one.  If
+                          enabled the `host` parameter to rules is used
+                          instead of the `subdomain` one.
+
+    .. versionadded:: 0.5
+        `sort_parameters` and `sort_key` was added.
+
+    .. versionadded:: 0.7
+        `encoding_errors` and `host_matching` was added.
+    """
+
+    #: A dict of default converters to be used.
+    default_converters = ImmutableDict(DEFAULT_CONVERTERS)
+
+    def __init__(
+        self,
+        rules=None,
+        default_subdomain="",
+        charset="utf-8",
+        strict_slashes=True,
+        redirect_defaults=True,
+        converters=None,
+        sort_parameters=False,
+        sort_key=None,
+        encoding_errors="replace",
+        host_matching=False,
+    ):
+        self._rules = []
+        self._rules_by_endpoint = {}
+        self._remap = True
+        self._remap_lock = Lock()
+
+        self.default_subdomain = default_subdomain
+        self.charset = charset
+        self.encoding_errors = encoding_errors
+        self.strict_slashes = strict_slashes
+        self.redirect_defaults = redirect_defaults
+        self.host_matching = host_matching
+
+        self.converters = self.default_converters.copy()
+        if converters:
+            self.converters.update(converters)
+
+        self.sort_parameters = sort_parameters
+        self.sort_key = sort_key
+
+        for rulefactory in rules or ():
+            self.add(rulefactory)
+
+    def is_endpoint_expecting(self, endpoint, *arguments):
+        """Iterate over all rules and check if the endpoint expects
+        the arguments provided.  This is for example useful if you have
+        some URLs that expect a language code and others that do not and
+        you want to wrap the builder a bit so that the current language
+        code is automatically added if not provided but endpoints expect
+        it.
+
+        :param endpoint: the endpoint to check.
+        :param arguments: this function accepts one or more arguments
+                          as positional arguments.  Each one of them is
+                          checked.
+        """
+        self.update()
+        arguments = set(arguments)
+        for rule in self._rules_by_endpoint[endpoint]:
+            if arguments.issubset(rule.arguments):
+                return True
+        return False
+
+    def iter_rules(self, endpoint=None):
+        """Iterate over all rules or the rules of an endpoint.
+
+        :param endpoint: if provided only the rules for that endpoint
+                         are returned.
+        :return: an iterator
+        """
+        self.update()
+        if endpoint is not None:
+            return iter(self._rules_by_endpoint[endpoint])
+        return iter(self._rules)
+
+    def add(self, rulefactory):
+        """Add a new rule or factory to the map and bind it.  Requires that the
+        rule is not bound to another map.
+
+        :param rulefactory: a :class:`Rule` or :class:`RuleFactory`
+        """
+        for rule in rulefactory.get_rules(self):
+            rule.bind(self)
+            self._rules.append(rule)
+            self._rules_by_endpoint.setdefault(rule.endpoint, []).append(rule)
+        self._remap = True
+
+    def bind(
+        self,
+        server_name,
+        script_name=None,
+        subdomain=None,
+        url_scheme="http",
+        default_method="GET",
+        path_info=None,
+        query_args=None,
+    ):
+        """Return a new :class:`MapAdapter` with the details specified to the
+        call.  Note that `script_name` will default to ``'/'`` if not further
+        specified or `None`.  The `server_name` at least is a requirement
+        because the HTTP RFC requires absolute URLs for redirects and so all
+        redirect exceptions raised by Werkzeug will contain the full canonical
+        URL.
+
+        If no path_info is passed to :meth:`match` it will use the default path
+        info passed to bind.  While this doesn't really make sense for
+        manual bind calls, it's useful if you bind a map to a WSGI
+        environment which already contains the path info.
+
+        `subdomain` will default to the `default_subdomain` for this map if
+        no defined. If there is no `default_subdomain` you cannot use the
+        subdomain feature.
+
+        .. versionadded:: 0.7
+           `query_args` added
+
+        .. versionadded:: 0.8
+           `query_args` can now also be a string.
+
+        .. versionchanged:: 0.15
+            ``path_info`` defaults to ``'/'`` if ``None``.
+        """
+        server_name = server_name.lower()
+        if self.host_matching:
+            if subdomain is not None:
+                raise RuntimeError("host matching enabled and a subdomain was provided")
+        elif subdomain is None:
+            subdomain = self.default_subdomain
+        if script_name is None:
+            script_name = "/"
+        if path_info is None:
+            path_info = "/"
+        try:
+            server_name = _encode_idna(server_name)
+        except UnicodeError:
+            raise BadHost()
+        return MapAdapter(
+            self,
+            server_name,
+            script_name,
+            subdomain,
+            url_scheme,
+            path_info,
+            default_method,
+            query_args,
+        )
+
+    def bind_to_environ(self, environ, server_name=None, subdomain=None):
+        """Like :meth:`bind` but you can pass it an WSGI environment and it
+        will fetch the information from that dictionary.  Note that because of
+        limitations in the protocol there is no way to get the current
+        subdomain and real `server_name` from the environment.  If you don't
+        provide it, Werkzeug will use `SERVER_NAME` and `SERVER_PORT` (or
+        `HTTP_HOST` if provided) as used `server_name` with disabled subdomain
+        feature.
+
+        If `subdomain` is `None` but an environment and a server name is
+        provided it will calculate the current subdomain automatically.
+        Example: `server_name` is ``'example.com'`` and the `SERVER_NAME`
+        in the wsgi `environ` is ``'staging.dev.example.com'`` the calculated
+        subdomain will be ``'staging.dev'``.
+
+        If the object passed as environ has an environ attribute, the value of
+        this attribute is used instead.  This allows you to pass request
+        objects.  Additionally `PATH_INFO` added as a default of the
+        :class:`MapAdapter` so that you don't have to pass the path info to
+        the match method.
+
+        .. versionchanged:: 0.5
+            previously this method accepted a bogus `calculate_subdomain`
+            parameter that did not have any effect.  It was removed because
+            of that.
+
+        .. versionchanged:: 0.8
+           This will no longer raise a ValueError when an unexpected server
+           name was passed.
+
+        :param environ: a WSGI environment.
+        :param server_name: an optional server name hint (see above).
+        :param subdomain: optionally the current subdomain (see above).
+        """
+        environ = _get_environ(environ)
+
+        wsgi_server_name = get_host(environ).lower()
+
+        if server_name is None:
+            server_name = wsgi_server_name
+        else:
+            server_name = server_name.lower()
+
+        if subdomain is None and not self.host_matching:
+            cur_server_name = wsgi_server_name.split(".")
+            real_server_name = server_name.split(".")
+            offset = -len(real_server_name)
+            if cur_server_name[offset:] != real_server_name:
+                # This can happen even with valid configs if the server was
+                # accesssed directly by IP address under some situations.
+                # Instead of raising an exception like in Werkzeug 0.7 or
+                # earlier we go by an invalid subdomain which will result
+                # in a 404 error on matching.
+                subdomain = "<invalid>"
+            else:
+                subdomain = ".".join(filter(None, cur_server_name[:offset]))
+
+        def _get_wsgi_string(name):
+            val = environ.get(name)
+            if val is not None:
+                return wsgi_decoding_dance(val, self.charset)
+
+        script_name = _get_wsgi_string("SCRIPT_NAME")
+        path_info = _get_wsgi_string("PATH_INFO")
+        query_args = _get_wsgi_string("QUERY_STRING")
+        return Map.bind(
+            self,
+            server_name,
+            script_name,
+            subdomain,
+            environ["wsgi.url_scheme"],
+            environ["REQUEST_METHOD"],
+            path_info,
+            query_args=query_args,
+        )
+
+    def update(self):
+        """Called before matching and building to keep the compiled rules
+        in the correct order after things changed.
+        """
+        if not self._remap:
+            return
+
+        with self._remap_lock:
+            if not self._remap:
+                return
+
+            self._rules.sort(key=lambda x: x.match_compare_key())
+            for rules in itervalues(self._rules_by_endpoint):
+                rules.sort(key=lambda x: x.build_compare_key())
+            self._remap = False
+
+    def __repr__(self):
+        rules = self.iter_rules()
+        return "%s(%s)" % (self.__class__.__name__, pformat(list(rules)))
+
+
+class MapAdapter(object):
+
+    """Returned by :meth:`Map.bind` or :meth:`Map.bind_to_environ` and does
+    the URL matching and building based on runtime information.
+    """
+
+    def __init__(
+        self,
+        map,
+        server_name,
+        script_name,
+        subdomain,
+        url_scheme,
+        path_info,
+        default_method,
+        query_args=None,
+    ):
+        self.map = map
+        self.server_name = to_unicode(server_name)
+        script_name = to_unicode(script_name)
+        if not script_name.endswith(u"/"):
+            script_name += u"/"
+        self.script_name = script_name
+        self.subdomain = to_unicode(subdomain)
+        self.url_scheme = to_unicode(url_scheme)
+        self.path_info = to_unicode(path_info)
+        self.default_method = to_unicode(default_method)
+        self.query_args = query_args
+
+    def dispatch(
+        self, view_func, path_info=None, method=None, catch_http_exceptions=False
+    ):
+        """Does the complete dispatching process.  `view_func` is called with
+        the endpoint and a dict with the values for the view.  It should
+        look up the view function, call it, and return a response object
+        or WSGI application.  http exceptions are not caught by default
+        so that applications can display nicer error messages by just
+        catching them by hand.  If you want to stick with the default
+        error messages you can pass it ``catch_http_exceptions=True`` and
+        it will catch the http exceptions.
+
+        Here a small example for the dispatch usage::
+
+            from werkzeug.wrappers import Request, Response
+            from werkzeug.wsgi import responder
+            from werkzeug.routing import Map, Rule
+
+            def on_index(request):
+                return Response('Hello from the index')
+
+            url_map = Map([Rule('/', endpoint='index')])
+            views = {'index': on_index}
+
+            @responder
+            def application(environ, start_response):
+                request = Request(environ)
+                urls = url_map.bind_to_environ(environ)
+                return urls.dispatch(lambda e, v: views[e](request, **v),
+                                     catch_http_exceptions=True)
+
+        Keep in mind that this method might return exception objects, too, so
+        use :class:`Response.force_type` to get a response object.
+
+        :param view_func: a function that is called with the endpoint as
+                          first argument and the value dict as second.  Has
+                          to dispatch to the actual view function with this
+                          information.  (see above)
+        :param path_info: the path info to use for matching.  Overrides the
+                          path info specified on binding.
+        :param method: the HTTP method used for matching.  Overrides the
+                       method specified on binding.
+        :param catch_http_exceptions: set to `True` to catch any of the
+                                      werkzeug :class:`HTTPException`\\s.
+        """
+        try:
+            try:
+                endpoint, args = self.match(path_info, method)
+            except RequestRedirect as e:
+                return e
+            return view_func(endpoint, args)
+        except HTTPException as e:
+            if catch_http_exceptions:
+                return e
+            raise
+
+    def match(self, path_info=None, method=None, return_rule=False, query_args=None):
+        """The usage is simple: you just pass the match method the current
+        path info as well as the method (which defaults to `GET`).  The
+        following things can then happen:
+
+        - you receive a `NotFound` exception that indicates that no URL is
+          matching.  A `NotFound` exception is also a WSGI application you
+          can call to get a default page not found page (happens to be the
+          same object as `werkzeug.exceptions.NotFound`)
+
+        - you receive a `MethodNotAllowed` exception that indicates that there
+          is a match for this URL but not for the current request method.
+          This is useful for RESTful applications.
+
+        - you receive a `RequestRedirect` exception with a `new_url`
+          attribute.  This exception is used to notify you about a request
+          Werkzeug requests from your WSGI application.  This is for example the
+          case if you request ``/foo`` although the correct URL is ``/foo/``
+          You can use the `RequestRedirect` instance as response-like object
+          similar to all other subclasses of `HTTPException`.
+
+        - you get a tuple in the form ``(endpoint, arguments)`` if there is
+          a match (unless `return_rule` is True, in which case you get a tuple
+          in the form ``(rule, arguments)``)
+
+        If the path info is not passed to the match method the default path
+        info of the map is used (defaults to the root URL if not defined
+        explicitly).
+
+        All of the exceptions raised are subclasses of `HTTPException` so they
+        can be used as WSGI responses. They will all render generic error or
+        redirect pages.
+
+        Here is a small example for matching:
+
+        >>> m = Map([
+        ...     Rule('/', endpoint='index'),
+        ...     Rule('/downloads/', endpoint='downloads/index'),
+        ...     Rule('/downloads/<int:id>', endpoint='downloads/show')
+        ... ])
+        >>> urls = m.bind("example.com", "/")
+        >>> urls.match("/", "GET")
+        ('index', {})
+        >>> urls.match("/downloads/42")
+        ('downloads/show', {'id': 42})
+
+        And here is what happens on redirect and missing URLs:
+
+        >>> urls.match("/downloads")
+        Traceback (most recent call last):
+          ...
+        RequestRedirect: http://example.com/downloads/
+        >>> urls.match("/missing")
+        Traceback (most recent call last):
+          ...
+        NotFound: 404 Not Found
+
+        :param path_info: the path info to use for matching.  Overrides the
+                          path info specified on binding.
+        :param method: the HTTP method used for matching.  Overrides the
+                       method specified on binding.
+        :param return_rule: return the rule that matched instead of just the
+                            endpoint (defaults to `False`).
+        :param query_args: optional query arguments that are used for
+                           automatic redirects as string or dictionary.  It's
+                           currently not possible to use the query arguments
+                           for URL matching.
+
+        .. versionadded:: 0.6
+           `return_rule` was added.
+
+        .. versionadded:: 0.7
+           `query_args` was added.
+
+        .. versionchanged:: 0.8
+           `query_args` can now also be a string.
+        """
+        self.map.update()
+        if path_info is None:
+            path_info = self.path_info
+        else:
+            path_info = to_unicode(path_info, self.map.charset)
+        if query_args is None:
+            query_args = self.query_args
+        method = (method or self.default_method).upper()
+
+        path = u"%s|%s" % (
+            self.map.host_matching and self.server_name or self.subdomain,
+            path_info and "/%s" % path_info.lstrip("/"),
+        )
+
+        have_match_for = set()
+        for rule in self.map._rules:
+            try:
+                rv = rule.match(path, method)
+            except RequestSlash:
+                raise RequestRedirect(
+                    self.make_redirect_url(
+                        url_quote(path_info, self.map.charset, safe="/:|+") + "/",
+                        query_args,
+                    )
+                )
+            except RequestAliasRedirect as e:
+                raise RequestRedirect(
+                    self.make_alias_redirect_url(
+                        path, rule.endpoint, e.matched_values, method, query_args
+                    )
+                )
+            if rv is None:
+                continue
+            if rule.methods is not None and method not in rule.methods:
+                have_match_for.update(rule.methods)
+                continue
+
+            if self.map.redirect_defaults:
+                redirect_url = self.get_default_redirect(rule, method, rv, query_args)
+                if redirect_url is not None:
+                    raise RequestRedirect(redirect_url)
+
+            if rule.redirect_to is not None:
+                if isinstance(rule.redirect_to, string_types):
+
+                    def _handle_match(match):
+                        value = rv[match.group(1)]
+                        return rule._converters[match.group(1)].to_url(value)
+
+                    redirect_url = _simple_rule_re.sub(_handle_match, rule.redirect_to)
+                else:
+                    redirect_url = rule.redirect_to(self, **rv)
+                raise RequestRedirect(
+                    str(
+                        url_join(
+                            "%s://%s%s%s"
+                            % (
+                                self.url_scheme or "http",
+                                self.subdomain + "." if self.subdomain else "",
+                                self.server_name,
+                                self.script_name,
+                            ),
+                            redirect_url,
+                        )
+                    )
+                )
+
+            if return_rule:
+                return rule, rv
+            else:
+                return rule.endpoint, rv
+
+        if have_match_for:
+            raise MethodNotAllowed(valid_methods=list(have_match_for))
+        raise NotFound()
+
+    def test(self, path_info=None, method=None):
+        """Test if a rule would match.  Works like `match` but returns `True`
+        if the URL matches, or `False` if it does not exist.
+
+        :param path_info: the path info to use for matching.  Overrides the
+                          path info specified on binding.
+        :param method: the HTTP method used for matching.  Overrides the
+                       method specified on binding.
+        """
+        try:
+            self.match(path_info, method)
+        except RequestRedirect:
+            pass
+        except HTTPException:
+            return False
+        return True
+
+    def allowed_methods(self, path_info=None):
+        """Returns the valid methods that match for a given path.
+
+        .. versionadded:: 0.7
+        """
+        try:
+            self.match(path_info, method="--")
+        except MethodNotAllowed as e:
+            return e.valid_methods
+        except HTTPException:
+            pass
+        return []
+
+    def get_host(self, domain_part):
+        """Figures out the full host name for the given domain part.  The
+        domain part is a subdomain in case host matching is disabled or
+        a full host name.
+        """
+        if self.map.host_matching:
+            if domain_part is None:
+                return self.server_name
+            return to_unicode(domain_part, "ascii")
+        subdomain = domain_part
+        if subdomain is None:
+            subdomain = self.subdomain
+        else:
+            subdomain = to_unicode(subdomain, "ascii")
+        return (subdomain + u"." if subdomain else u"") + self.server_name
+
+    def get_default_redirect(self, rule, method, values, query_args):
+        """A helper that returns the URL to redirect to if it finds one.
+        This is used for default redirecting only.
+
+        :internal:
+        """
+        assert self.map.redirect_defaults
+        for r in self.map._rules_by_endpoint[rule.endpoint]:
+            # every rule that comes after this one, including ourself
+            # has a lower priority for the defaults.  We order the ones
+            # with the highest priority up for building.
+            if r is rule:
+                break
+            if r.provides_defaults_for(rule) and r.suitable_for(values, method):
+                values.update(r.defaults)
+                domain_part, path = r.build(values)
+                return self.make_redirect_url(path, query_args, domain_part=domain_part)
+
+    def encode_query_args(self, query_args):
+        if not isinstance(query_args, string_types):
+            query_args = url_encode(query_args, self.map.charset)
+        return query_args
+
+    def make_redirect_url(self, path_info, query_args=None, domain_part=None):
+        """Creates a redirect URL.
+
+        :internal:
+        """
+        suffix = ""
+        if query_args:
+            suffix = "?" + self.encode_query_args(query_args)
+        return str(
+            "%s://%s/%s%s"
+            % (
+                self.url_scheme or "http",
+                self.get_host(domain_part),
+                posixpath.join(
+                    self.script_name[:-1].lstrip("/"), path_info.lstrip("/")
+                ),
+                suffix,
+            )
+        )
+
+    def make_alias_redirect_url(self, path, endpoint, values, method, query_args):
+        """Internally called to make an alias redirect URL."""
+        url = self.build(
+            endpoint, values, method, append_unknown=False, force_external=True
+        )
+        if query_args:
+            url += "?" + self.encode_query_args(query_args)
+        assert url != path, "detected invalid alias setting. No canonical URL found"
+        return url
+
+    def _partial_build(self, endpoint, values, method, append_unknown):
+        """Helper for :meth:`build`.  Returns subdomain and path for the
+        rule that accepts this endpoint, values and method.
+
+        :internal:
+        """
+        # in case the method is none, try with the default method first
+        if method is None:
+            rv = self._partial_build(
+                endpoint, values, self.default_method, append_unknown
+            )
+            if rv is not None:
+                return rv
+
+        # default method did not match or a specific method is passed,
+        # check all and go with first result.
+        for rule in self.map._rules_by_endpoint.get(endpoint, ()):
+            if rule.suitable_for(values, method):
+                rv = rule.build(values, append_unknown)
+                if rv is not None:
+                    return rv
+
+    def build(
+        self,
+        endpoint,
+        values=None,
+        method=None,
+        force_external=False,
+        append_unknown=True,
+    ):
+        """Building URLs works pretty much the other way round.  Instead of
+        `match` you call `build` and pass it the endpoint and a dict of
+        arguments for the placeholders.
+
+        The `build` function also accepts an argument called `force_external`
+        which, if you set it to `True` will force external URLs. Per default
+        external URLs (include the server name) will only be used if the
+        target URL is on a different subdomain.
+
+        >>> m = Map([
+        ...     Rule('/', endpoint='index'),
+        ...     Rule('/downloads/', endpoint='downloads/index'),
+        ...     Rule('/downloads/<int:id>', endpoint='downloads/show')
+        ... ])
+        >>> urls = m.bind("example.com", "/")
+        >>> urls.build("index", {})
+        '/'
+        >>> urls.build("downloads/show", {'id': 42})
+        '/downloads/42'
+        >>> urls.build("downloads/show", {'id': 42}, force_external=True)
+        'http://example.com/downloads/42'
+
+        Because URLs cannot contain non ASCII data you will always get
+        bytestrings back.  Non ASCII characters are urlencoded with the
+        charset defined on the map instance.
+
+        Additional values are converted to unicode and appended to the URL as
+        URL querystring parameters:
+
+        >>> urls.build("index", {'q': 'My Searchstring'})
+        '/?q=My+Searchstring'
+
+        When processing those additional values, lists are furthermore
+        interpreted as multiple values (as per
+        :py:class:`werkzeug.datastructures.MultiDict`):
+
+        >>> urls.build("index", {'q': ['a', 'b', 'c']})
+        '/?q=a&q=b&q=c'
+
+        Passing a ``MultiDict`` will also add multiple values:
+
+        >>> urls.build("index", MultiDict((('p', 'z'), ('q', 'a'), ('q', 'b'))))
+        '/?p=z&q=a&q=b'
+
+        If a rule does not exist when building a `BuildError` exception is
+        raised.
+
+        The build method accepts an argument called `method` which allows you
+        to specify the method you want to have an URL built for if you have
+        different methods for the same endpoint specified.
+
+        .. versionadded:: 0.6
+           the `append_unknown` parameter was added.
+
+        :param endpoint: the endpoint of the URL to build.
+        :param values: the values for the URL to build.  Unhandled values are
+                       appended to the URL as query parameters.
+        :param method: the HTTP method for the rule if there are different
+                       URLs for different methods on the same endpoint.
+        :param force_external: enforce full canonical external URLs. If the URL
+                               scheme is not provided, this will generate
+                               a protocol-relative URL.
+        :param append_unknown: unknown parameters are appended to the generated
+                               URL as query string argument.  Disable this
+                               if you want the builder to ignore those.
+        """
+        self.map.update()
+
+        if values:
+            if isinstance(values, MultiDict):
+                temp_values = {}
+                # iteritems(dict, values) is like `values.lists()`
+                # without the call or `list()` coercion overhead.
+                for key, value in iteritems(dict, values):
+                    if not value:
+                        continue
+                    if len(value) == 1:  # flatten single item lists
+                        value = value[0]
+                        if value is None:  # drop None
+                            continue
+                    temp_values[key] = value
+                values = temp_values
+            else:
+                # drop None
+                values = dict(i for i in iteritems(values) if i[1] is not None)
+        else:
+            values = {}
+
+        rv = self._partial_build(endpoint, values, method, append_unknown)
+        if rv is None:
+            raise BuildError(endpoint, values, method, self)
+        domain_part, path = rv
+
+        host = self.get_host(domain_part)
+
+        # shortcut this.
+        if not force_external and (
+            (self.map.host_matching and host == self.server_name)
+            or (not self.map.host_matching and domain_part == self.subdomain)
+        ):
+            return "%s/%s" % (self.script_name.rstrip("/"), path.lstrip("/"))
+        return str(
+            "%s//%s%s/%s"
+            % (
+                self.url_scheme + ":" if self.url_scheme else "",
+                host,
+                self.script_name[:-1],
+                path.lstrip("/"),
+            )
+        )
diff --git a/python/werkzeug/security.py b/python/werkzeug/security.py
new file mode 100644
index 0000000..1842afd
--- /dev/null
+++ b/python/werkzeug/security.py
@@ -0,0 +1,241 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.security
+    ~~~~~~~~~~~~~~~~~
+
+    Security related helpers such as secure password hashing tools.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import codecs
+import hashlib
+import hmac
+import os
+import posixpath
+from random import SystemRandom
+from struct import Struct
+
+from ._compat import izip
+from ._compat import PY2
+from ._compat import range_type
+from ._compat import text_type
+from ._compat import to_bytes
+from ._compat import to_native
+
+SALT_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+DEFAULT_PBKDF2_ITERATIONS = 150000
+
+_pack_int = Struct(">I").pack
+_builtin_safe_str_cmp = getattr(hmac, "compare_digest", None)
+_sys_rng = SystemRandom()
+_os_alt_seps = list(
+    sep for sep in [os.path.sep, os.path.altsep] if sep not in (None, "/")
+)
+
+
+def pbkdf2_hex(
+    data, salt, iterations=DEFAULT_PBKDF2_ITERATIONS, keylen=None, hashfunc=None
+):
+    """Like :func:`pbkdf2_bin`, but returns a hex-encoded string.
+
+    .. versionadded:: 0.9
+
+    :param data: the data to derive.
+    :param salt: the salt for the derivation.
+    :param iterations: the number of iterations.
+    :param keylen: the length of the resulting key.  If not provided,
+                   the digest size will be used.
+    :param hashfunc: the hash function to use.  This can either be the
+                     string name of a known hash function, or a function
+                     from the hashlib module.  Defaults to sha256.
+    """
+    rv = pbkdf2_bin(data, salt, iterations, keylen, hashfunc)
+    return to_native(codecs.encode(rv, "hex_codec"))
+
+
+def pbkdf2_bin(
+    data, salt, iterations=DEFAULT_PBKDF2_ITERATIONS, keylen=None, hashfunc=None
+):
+    """Returns a binary digest for the PBKDF2 hash algorithm of `data`
+    with the given `salt`. It iterates `iterations` times and produces a
+    key of `keylen` bytes. By default, SHA-256 is used as hash function;
+    a different hashlib `hashfunc` can be provided.
+
+    .. versionadded:: 0.9
+
+    :param data: the data to derive.
+    :param salt: the salt for the derivation.
+    :param iterations: the number of iterations.
+    :param keylen: the length of the resulting key.  If not provided
+                   the digest size will be used.
+    :param hashfunc: the hash function to use.  This can either be the
+                     string name of a known hash function or a function
+                     from the hashlib module.  Defaults to sha256.
+    """
+    if not hashfunc:
+        hashfunc = "sha256"
+
+    data = to_bytes(data)
+    salt = to_bytes(salt)
+
+    if callable(hashfunc):
+        _test_hash = hashfunc()
+        hash_name = getattr(_test_hash, "name", None)
+    else:
+        hash_name = hashfunc
+    return hashlib.pbkdf2_hmac(hash_name, data, salt, iterations, keylen)
+
+
+def safe_str_cmp(a, b):
+    """This function compares strings in somewhat constant time.  This
+    requires that the length of at least one string is known in advance.
+
+    Returns `True` if the two strings are equal, or `False` if they are not.
+
+    .. versionadded:: 0.7
+    """
+    if isinstance(a, text_type):
+        a = a.encode("utf-8")
+    if isinstance(b, text_type):
+        b = b.encode("utf-8")
+
+    if _builtin_safe_str_cmp is not None:
+        return _builtin_safe_str_cmp(a, b)
+
+    if len(a) != len(b):
+        return False
+
+    rv = 0
+    if PY2:
+        for x, y in izip(a, b):
+            rv |= ord(x) ^ ord(y)
+    else:
+        for x, y in izip(a, b):
+            rv |= x ^ y
+
+    return rv == 0
+
+
+def gen_salt(length):
+    """Generate a random string of SALT_CHARS with specified ``length``."""
+    if length <= 0:
+        raise ValueError("Salt length must be positive")
+    return "".join(_sys_rng.choice(SALT_CHARS) for _ in range_type(length))
+
+
+def _hash_internal(method, salt, password):
+    """Internal password hash helper.  Supports plaintext without salt,
+    unsalted and salted passwords.  In case salted passwords are used
+    hmac is used.
+    """
+    if method == "plain":
+        return password, method
+
+    if isinstance(password, text_type):
+        password = password.encode("utf-8")
+
+    if method.startswith("pbkdf2:"):
+        args = method[7:].split(":")
+        if len(args) not in (1, 2):
+            raise ValueError("Invalid number of arguments for PBKDF2")
+        method = args.pop(0)
+        iterations = args and int(args[0] or 0) or DEFAULT_PBKDF2_ITERATIONS
+        is_pbkdf2 = True
+        actual_method = "pbkdf2:%s:%d" % (method, iterations)
+    else:
+        is_pbkdf2 = False
+        actual_method = method
+
+    if is_pbkdf2:
+        if not salt:
+            raise ValueError("Salt is required for PBKDF2")
+        rv = pbkdf2_hex(password, salt, iterations, hashfunc=method)
+    elif salt:
+        if isinstance(salt, text_type):
+            salt = salt.encode("utf-8")
+        mac = _create_mac(salt, password, method)
+        rv = mac.hexdigest()
+    else:
+        rv = hashlib.new(method, password).hexdigest()
+    return rv, actual_method
+
+
+def _create_mac(key, msg, method):
+    if callable(method):
+        return hmac.HMAC(key, msg, method)
+
+    def hashfunc(d=b""):
+        return hashlib.new(method, d)
+
+    # Python 2.7 used ``hasattr(digestmod, '__call__')``
+    # to detect if hashfunc is callable
+    hashfunc.__call__ = hashfunc
+    return hmac.HMAC(key, msg, hashfunc)
+
+
+def generate_password_hash(password, method="pbkdf2:sha256", salt_length=8):
+    """Hash a password with the given method and salt with a string of
+    the given length. The format of the string returned includes the method
+    that was used so that :func:`check_password_hash` can check the hash.
+
+    The format for the hashed string looks like this::
+
+        method$salt$hash
+
+    This method can **not** generate unsalted passwords but it is possible
+    to set param method='plain' in order to enforce plaintext passwords.
+    If a salt is used, hmac is used internally to salt the password.
+
+    If PBKDF2 is wanted it can be enabled by setting the method to
+    ``pbkdf2:method:iterations`` where iterations is optional::
+
+        pbkdf2:sha256:80000$salt$hash
+        pbkdf2:sha256$salt$hash
+
+    :param password: the password to hash.
+    :param method: the hash method to use (one that hashlib supports). Can
+                   optionally be in the format ``pbkdf2:<method>[:iterations]``
+                   to enable PBKDF2.
+    :param salt_length: the length of the salt in letters.
+    """
+    salt = gen_salt(salt_length) if method != "plain" else ""
+    h, actual_method = _hash_internal(method, salt, password)
+    return "%s$%s$%s" % (actual_method, salt, h)
+
+
+def check_password_hash(pwhash, password):
+    """check a password against a given salted and hashed password value.
+    In order to support unsalted legacy passwords this method supports
+    plain text passwords, md5 and sha1 hashes (both salted and unsalted).
+
+    Returns `True` if the password matched, `False` otherwise.
+
+    :param pwhash: a hashed string like returned by
+                   :func:`generate_password_hash`.
+    :param password: the plaintext password to compare against the hash.
+    """
+    if pwhash.count("$") < 2:
+        return False
+    method, salt, hashval = pwhash.split("$", 2)
+    return safe_str_cmp(_hash_internal(method, salt, password)[0], hashval)
+
+
+def safe_join(directory, *pathnames):
+    """Safely join `directory` and one or more untrusted `pathnames`.  If this
+    cannot be done, this function returns ``None``.
+
+    :param directory: the base directory.
+    :param pathnames: the untrusted pathnames relative to that directory.
+    """
+    parts = [directory]
+    for filename in pathnames:
+        if filename != "":
+            filename = posixpath.normpath(filename)
+        for sep in _os_alt_seps:
+            if sep in filename:
+                return None
+        if os.path.isabs(filename) or filename == ".." or filename.startswith("../"):
+            return None
+        parts.append(filename)
+    return posixpath.join(*parts)
diff --git a/python/werkzeug/serving.py b/python/werkzeug/serving.py
new file mode 100644
index 0000000..ff9f880
--- /dev/null
+++ b/python/werkzeug/serving.py
@@ -0,0 +1,1074 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.serving
+    ~~~~~~~~~~~~~~~~
+
+    There are many ways to serve a WSGI application.  While you're developing
+    it you usually don't want a full blown webserver like Apache but a simple
+    standalone one.  From Python 2.5 onwards there is the `wsgiref`_ server in
+    the standard library.  If you're using older versions of Python you can
+    download the package from the cheeseshop.
+
+    However there are some caveats. Sourcecode won't reload itself when
+    changed and each time you kill the server using ``^C`` you get an
+    `KeyboardInterrupt` error.  While the latter is easy to solve the first
+    one can be a pain in the ass in some situations.
+
+    The easiest way is creating a small ``start-myproject.py`` that runs the
+    application::
+
+        #!/usr/bin/env python
+        # -*- coding: utf-8 -*-
+        from myproject import make_app
+        from werkzeug.serving import run_simple
+
+        app = make_app(...)
+        run_simple('localhost', 8080, app, use_reloader=True)
+
+    You can also pass it a `extra_files` keyword argument with a list of
+    additional files (like configuration files) you want to observe.
+
+    For bigger applications you should consider using `click`
+    (http://click.pocoo.org) instead of a simple start file.
+
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import io
+import os
+import signal
+import socket
+import sys
+
+import werkzeug
+from ._compat import PY2
+from ._compat import reraise
+from ._compat import WIN
+from ._compat import wsgi_encoding_dance
+from ._internal import _log
+from .exceptions import InternalServerError
+from .urls import uri_to_iri
+from .urls import url_parse
+from .urls import url_unquote
+
+try:
+    import socketserver
+    from http.server import BaseHTTPRequestHandler
+    from http.server import HTTPServer
+except ImportError:
+    import SocketServer as socketserver
+    from BaseHTTPServer import HTTPServer
+    from BaseHTTPServer import BaseHTTPRequestHandler
+
+try:
+    import ssl
+except ImportError:
+
+    class _SslDummy(object):
+        def __getattr__(self, name):
+            raise RuntimeError("SSL support unavailable")
+
+    ssl = _SslDummy()
+
+try:
+    import termcolor
+except ImportError:
+    termcolor = None
+
+
+def _get_openssl_crypto_module():
+    try:
+        from OpenSSL import crypto
+    except ImportError:
+        raise TypeError("Using ad-hoc certificates requires the pyOpenSSL library.")
+    else:
+        return crypto
+
+
+ThreadingMixIn = socketserver.ThreadingMixIn
+can_fork = hasattr(os, "fork")
+
+if can_fork:
+    ForkingMixIn = socketserver.ForkingMixIn
+else:
+
+    class ForkingMixIn(object):
+        pass
+
+
+try:
+    af_unix = socket.AF_UNIX
+except AttributeError:
+    af_unix = None
+
+
+LISTEN_QUEUE = 128
+can_open_by_fd = not WIN and hasattr(socket, "fromfd")
+
+# On Python 3, ConnectionError represents the same errnos as
+# socket.error from Python 2, while socket.error is an alias for the
+# more generic OSError.
+if PY2:
+    _ConnectionError = socket.error
+else:
+    _ConnectionError = ConnectionError
+
+
+class DechunkedInput(io.RawIOBase):
+    """An input stream that handles Transfer-Encoding 'chunked'"""
+
+    def __init__(self, rfile):
+        self._rfile = rfile
+        self._done = False
+        self._len = 0
+
+    def readable(self):
+        return True
+
+    def read_chunk_len(self):
+        try:
+            line = self._rfile.readline().decode("latin1")
+            _len = int(line.strip(), 16)
+        except ValueError:
+            raise IOError("Invalid chunk header")
+        if _len < 0:
+            raise IOError("Negative chunk length not allowed")
+        return _len
+
+    def readinto(self, buf):
+        read = 0
+        while not self._done and read < len(buf):
+            if self._len == 0:
+                # This is the first chunk or we fully consumed the previous
+                # one. Read the next length of the next chunk
+                self._len = self.read_chunk_len()
+
+            if self._len == 0:
+                # Found the final chunk of size 0. The stream is now exhausted,
+                # but there is still a final newline that should be consumed
+                self._done = True
+
+            if self._len > 0:
+                # There is data (left) in this chunk, so append it to the
+                # buffer. If this operation fully consumes the chunk, this will
+                # reset self._len to 0.
+                n = min(len(buf), self._len)
+                buf[read : read + n] = self._rfile.read(n)
+                self._len -= n
+                read += n
+
+            if self._len == 0:
+                # Skip the terminating newline of a chunk that has been fully
+                # consumed. This also applies to the 0-sized final chunk
+                terminator = self._rfile.readline()
+                if terminator not in (b"\n", b"\r\n", b"\r"):
+                    raise IOError("Missing chunk terminating newline")
+
+        return read
+
+
+class WSGIRequestHandler(BaseHTTPRequestHandler, object):
+
+    """A request handler that implements WSGI dispatching."""
+
+    @property
+    def server_version(self):
+        return "Werkzeug/" + werkzeug.__version__
+
+    def make_environ(self):
+        request_url = url_parse(self.path)
+
+        def shutdown_server():
+            self.server.shutdown_signal = True
+
+        url_scheme = "http" if self.server.ssl_context is None else "https"
+        if not self.client_address:
+            self.client_address = "<local>"
+        if isinstance(self.client_address, str):
+            self.client_address = (self.client_address, 0)
+        else:
+            pass
+        path_info = url_unquote(request_url.path)
+
+        environ = {
+            "wsgi.version": (1, 0),
+            "wsgi.url_scheme": url_scheme,
+            "wsgi.input": self.rfile,
+            "wsgi.errors": sys.stderr,
+            "wsgi.multithread": self.server.multithread,
+            "wsgi.multiprocess": self.server.multiprocess,
+            "wsgi.run_once": False,
+            "werkzeug.server.shutdown": shutdown_server,
+            "SERVER_SOFTWARE": self.server_version,
+            "REQUEST_METHOD": self.command,
+            "SCRIPT_NAME": "",
+            "PATH_INFO": wsgi_encoding_dance(path_info),
+            "QUERY_STRING": wsgi_encoding_dance(request_url.query),
+            # Non-standard, added by mod_wsgi, uWSGI
+            "REQUEST_URI": wsgi_encoding_dance(self.path),
+            # Non-standard, added by gunicorn
+            "RAW_URI": wsgi_encoding_dance(self.path),
+            "REMOTE_ADDR": self.address_string(),
+            "REMOTE_PORT": self.port_integer(),
+            "SERVER_NAME": self.server.server_address[0],
+            "SERVER_PORT": str(self.server.server_address[1]),
+            "SERVER_PROTOCOL": self.request_version,
+        }
+
+        for key, value in self.get_header_items():
+            key = key.upper().replace("-", "_")
+            value = value.replace("\r\n", "")
+            if key not in ("CONTENT_TYPE", "CONTENT_LENGTH"):
+                key = "HTTP_" + key
+                if key in environ:
+                    value = "{},{}".format(environ[key], value)
+            environ[key] = value
+
+        if environ.get("HTTP_TRANSFER_ENCODING", "").strip().lower() == "chunked":
+            environ["wsgi.input_terminated"] = True
+            environ["wsgi.input"] = DechunkedInput(environ["wsgi.input"])
+
+        if request_url.scheme and request_url.netloc:
+            environ["HTTP_HOST"] = request_url.netloc
+
+        return environ
+
+    def run_wsgi(self):
+        if self.headers.get("Expect", "").lower().strip() == "100-continue":
+            self.wfile.write(b"HTTP/1.1 100 Continue\r\n\r\n")
+
+        self.environ = environ = self.make_environ()
+        headers_set = []
+        headers_sent = []
+
+        def write(data):
+            assert headers_set, "write() before start_response"
+            if not headers_sent:
+                status, response_headers = headers_sent[:] = headers_set
+                try:
+                    code, msg = status.split(None, 1)
+                except ValueError:
+                    code, msg = status, ""
+                code = int(code)
+                self.send_response(code, msg)
+                header_keys = set()
+                for key, value in response_headers:
+                    self.send_header(key, value)
+                    key = key.lower()
+                    header_keys.add(key)
+                if not (
+                    "content-length" in header_keys
+                    or environ["REQUEST_METHOD"] == "HEAD"
+                    or code < 200
+                    or code in (204, 304)
+                ):
+                    self.close_connection = True
+                    self.send_header("Connection", "close")
+                if "server" not in header_keys:
+                    self.send_header("Server", self.version_string())
+                if "date" not in header_keys:
+                    self.send_header("Date", self.date_time_string())
+                self.end_headers()
+
+            assert isinstance(data, bytes), "applications must write bytes"
+            self.wfile.write(data)
+            self.wfile.flush()
+
+        def start_response(status, response_headers, exc_info=None):
+            if exc_info:
+                try:
+                    if headers_sent:
+                        reraise(*exc_info)
+                finally:
+                    exc_info = None
+            elif headers_set:
+                raise AssertionError("Headers already set")
+            headers_set[:] = [status, response_headers]
+            return write
+
+        def execute(app):
+            application_iter = app(environ, start_response)
+            try:
+                for data in application_iter:
+                    write(data)
+                if not headers_sent:
+                    write(b"")
+            finally:
+                if hasattr(application_iter, "close"):
+                    application_iter.close()
+                application_iter = None
+
+        try:
+            execute(self.server.app)
+        except (_ConnectionError, socket.timeout) as e:
+            self.connection_dropped(e, environ)
+        except Exception:
+            if self.server.passthrough_errors:
+                raise
+            from .debug.tbtools import get_current_traceback
+
+            traceback = get_current_traceback(ignore_system_exceptions=True)
+            try:
+                # if we haven't yet sent the headers but they are set
+                # we roll back to be able to set them again.
+                if not headers_sent:
+                    del headers_set[:]
+                execute(InternalServerError())
+            except Exception:
+                pass
+            self.server.log("error", "Error on request:\n%s", traceback.plaintext)
+
+    def handle(self):
+        """Handles a request ignoring dropped connections."""
+        rv = None
+        try:
+            rv = BaseHTTPRequestHandler.handle(self)
+        except (_ConnectionError, socket.timeout) as e:
+            self.connection_dropped(e)
+        except Exception as e:
+            if self.server.ssl_context is None or not is_ssl_error(e):
+                raise
+        if self.server.shutdown_signal:
+            self.initiate_shutdown()
+        return rv
+
+    def initiate_shutdown(self):
+        """A horrible, horrible way to kill the server for Python 2.6 and
+        later.  It's the best we can do.
+        """
+        # Windows does not provide SIGKILL, go with SIGTERM then.
+        sig = getattr(signal, "SIGKILL", signal.SIGTERM)
+        # reloader active
+        if is_running_from_reloader():
+            os.kill(os.getpid(), sig)
+        # python 2.7
+        self.server._BaseServer__shutdown_request = True
+        # python 2.6
+        self.server._BaseServer__serving = False
+
+    def connection_dropped(self, error, environ=None):
+        """Called if the connection was closed by the client.  By default
+        nothing happens.
+        """
+
+    def handle_one_request(self):
+        """Handle a single HTTP request."""
+        self.raw_requestline = self.rfile.readline()
+        if not self.raw_requestline:
+            self.close_connection = 1
+        elif self.parse_request():
+            return self.run_wsgi()
+
+    def send_response(self, code, message=None):
+        """Send the response header and log the response code."""
+        self.log_request(code)
+        if message is None:
+            message = code in self.responses and self.responses[code][0] or ""
+        if self.request_version != "HTTP/0.9":
+            hdr = "%s %d %s\r\n" % (self.protocol_version, code, message)
+            self.wfile.write(hdr.encode("ascii"))
+
+    def version_string(self):
+        return BaseHTTPRequestHandler.version_string(self).strip()
+
+    def address_string(self):
+        if getattr(self, "environ", None):
+            return self.environ["REMOTE_ADDR"]
+        elif not self.client_address:
+            return "<local>"
+        elif isinstance(self.client_address, str):
+            return self.client_address
+        else:
+            return self.client_address[0]
+
+    def port_integer(self):
+        return self.client_address[1]
+
+    def log_request(self, code="-", size="-"):
+        try:
+            path = uri_to_iri(self.path)
+            msg = "%s %s %s" % (self.command, path, self.request_version)
+        except AttributeError:
+            # path isn't set if the requestline was bad
+            msg = self.requestline
+
+        code = str(code)
+
+        if termcolor:
+            color = termcolor.colored
+
+            if code[0] == "1":  # 1xx - Informational
+                msg = color(msg, attrs=["bold"])
+            elif code[0] == "2":  # 2xx - Success
+                msg = color(msg, color="white")
+            elif code == "304":  # 304 - Resource Not Modified
+                msg = color(msg, color="cyan")
+            elif code[0] == "3":  # 3xx - Redirection
+                msg = color(msg, color="green")
+            elif code == "404":  # 404 - Resource Not Found
+                msg = color(msg, color="yellow")
+            elif code[0] == "4":  # 4xx - Client Error
+                msg = color(msg, color="red", attrs=["bold"])
+            else:  # 5xx, or any other response
+                msg = color(msg, color="magenta", attrs=["bold"])
+
+        self.log("info", '"%s" %s %s', msg, code, size)
+
+    def log_error(self, *args):
+        self.log("error", *args)
+
+    def log_message(self, format, *args):
+        self.log("info", format, *args)
+
+    def log(self, type, message, *args):
+        _log(
+            type,
+            "%s - - [%s] %s\n"
+            % (self.address_string(), self.log_date_time_string(), message % args),
+        )
+
+    def get_header_items(self):
+        """
+        Get an iterable list of key/value pairs representing headers.
+
+        This function provides Python 2/3 compatibility as related to the
+        parsing of request headers. Python 2.7 is not compliant with
+        RFC 3875 Section 4.1.18 which requires multiple values for headers
+        to be provided or RFC 2616 which allows for folding of multi-line
+        headers. This function will return a matching list regardless
+        of Python version. It can be removed once Python 2.7 support
+        is dropped.
+
+        :return: List of tuples containing header hey/value pairs
+        """
+        if PY2:
+            # For Python 2, process the headers manually according to
+            # W3C RFC 2616 Section 4.2.
+            items = []
+            for header in self.headers.headers:
+                # Remove "\r\n" from the header and split on ":" to get
+                # the field name and value.
+                try:
+                    key, value = header[0:-2].split(":", 1)
+                except ValueError:
+                    # If header could not be slit with : but starts with white
+                    # space and it follows an existing header, it's a folded
+                    # header.
+                    if header[0] in ("\t", " ") and items:
+                        # Pop off the last header
+                        key, value = items.pop()
+                        # Append the current header to the value of the last
+                        # header which will be placed back on the end of the
+                        # list
+                        value = value + header
+                    # Otherwise it's just a bad header and should error
+                    else:
+                        # Re-raise the value error
+                        raise
+
+                # Add the key and the value once stripped of leading
+                # white space. The specification allows for stripping
+                # trailing white space but the Python 3 code does not
+                # strip trailing white space. Therefore, trailing space
+                # will be left as is to match the Python 3 behavior.
+                items.append((key, value.lstrip()))
+        else:
+            items = self.headers.items()
+
+        return items
+
+
+#: backwards compatible name if someone is subclassing it
+BaseRequestHandler = WSGIRequestHandler
+
+
+def generate_adhoc_ssl_pair(cn=None):
+    from random import random
+
+    crypto = _get_openssl_crypto_module()
+
+    # pretty damn sure that this is not actually accepted by anyone
+    if cn is None:
+        cn = "*"
+
+    cert = crypto.X509()
+    cert.set_serial_number(int(random() * sys.maxsize))
+    cert.gmtime_adj_notBefore(0)
+    cert.gmtime_adj_notAfter(60 * 60 * 24 * 365)
+
+    subject = cert.get_subject()
+    subject.CN = cn
+    subject.O = "Dummy Certificate"  # noqa: E741
+
+    issuer = cert.get_issuer()
+    issuer.CN = subject.CN
+    issuer.O = subject.O  # noqa: E741
+
+    pkey = crypto.PKey()
+    pkey.generate_key(crypto.TYPE_RSA, 2048)
+    cert.set_pubkey(pkey)
+    cert.sign(pkey, "sha256")
+
+    return cert, pkey
+
+
+def make_ssl_devcert(base_path, host=None, cn=None):
+    """Creates an SSL key for development.  This should be used instead of
+    the ``'adhoc'`` key which generates a new cert on each server start.
+    It accepts a path for where it should store the key and cert and
+    either a host or CN.  If a host is given it will use the CN
+    ``*.host/CN=host``.
+
+    For more information see :func:`run_simple`.
+
+    .. versionadded:: 0.9
+
+    :param base_path: the path to the certificate and key.  The extension
+                      ``.crt`` is added for the certificate, ``.key`` is
+                      added for the key.
+    :param host: the name of the host.  This can be used as an alternative
+                 for the `cn`.
+    :param cn: the `CN` to use.
+    """
+    from OpenSSL import crypto
+
+    if host is not None:
+        cn = "*.%s/CN=%s" % (host, host)
+    cert, pkey = generate_adhoc_ssl_pair(cn=cn)
+
+    cert_file = base_path + ".crt"
+    pkey_file = base_path + ".key"
+
+    with open(cert_file, "wb") as f:
+        f.write(crypto.dump_certificate(crypto.FILETYPE_PEM, cert))
+    with open(pkey_file, "wb") as f:
+        f.write(crypto.dump_privatekey(crypto.FILETYPE_PEM, pkey))
+
+    return cert_file, pkey_file
+
+
+def generate_adhoc_ssl_context():
+    """Generates an adhoc SSL context for the development server."""
+    crypto = _get_openssl_crypto_module()
+    import tempfile
+    import atexit
+
+    cert, pkey = generate_adhoc_ssl_pair()
+    cert_handle, cert_file = tempfile.mkstemp()
+    pkey_handle, pkey_file = tempfile.mkstemp()
+    atexit.register(os.remove, pkey_file)
+    atexit.register(os.remove, cert_file)
+
+    os.write(cert_handle, crypto.dump_certificate(crypto.FILETYPE_PEM, cert))
+    os.write(pkey_handle, crypto.dump_privatekey(crypto.FILETYPE_PEM, pkey))
+    os.close(cert_handle)
+    os.close(pkey_handle)
+    ctx = load_ssl_context(cert_file, pkey_file)
+    return ctx
+
+
+def load_ssl_context(cert_file, pkey_file=None, protocol=None):
+    """Loads SSL context from cert/private key files and optional protocol.
+    Many parameters are directly taken from the API of
+    :py:class:`ssl.SSLContext`.
+
+    :param cert_file: Path of the certificate to use.
+    :param pkey_file: Path of the private key to use. If not given, the key
+                      will be obtained from the certificate file.
+    :param protocol: One of the ``PROTOCOL_*`` constants in the stdlib ``ssl``
+                     module. Defaults to ``PROTOCOL_SSLv23``.
+    """
+    if protocol is None:
+        protocol = ssl.PROTOCOL_SSLv23
+    ctx = _SSLContext(protocol)
+    ctx.load_cert_chain(cert_file, pkey_file)
+    return ctx
+
+
+class _SSLContext(object):
+
+    """A dummy class with a small subset of Python3's ``ssl.SSLContext``, only
+    intended to be used with and by Werkzeug."""
+
+    def __init__(self, protocol):
+        self._protocol = protocol
+        self._certfile = None
+        self._keyfile = None
+        self._password = None
+
+    def load_cert_chain(self, certfile, keyfile=None, password=None):
+        self._certfile = certfile
+        self._keyfile = keyfile or certfile
+        self._password = password
+
+    def wrap_socket(self, sock, **kwargs):
+        return ssl.wrap_socket(
+            sock,
+            keyfile=self._keyfile,
+            certfile=self._certfile,
+            ssl_version=self._protocol,
+            **kwargs
+        )
+
+
+def is_ssl_error(error=None):
+    """Checks if the given error (or the current one) is an SSL error."""
+    exc_types = (ssl.SSLError,)
+    try:
+        from OpenSSL.SSL import Error
+
+        exc_types += (Error,)
+    except ImportError:
+        pass
+
+    if error is None:
+        error = sys.exc_info()[1]
+    return isinstance(error, exc_types)
+
+
+def select_address_family(host, port):
+    """Return ``AF_INET4``, ``AF_INET6``, or ``AF_UNIX`` depending on
+    the host and port."""
+    # disabled due to problems with current ipv6 implementations
+    # and various operating systems.  Probably this code also is
+    # not supposed to work, but I can't come up with any other
+    # ways to implement this.
+    # try:
+    #     info = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
+    #                               socket.SOCK_STREAM, 0,
+    #                               socket.AI_PASSIVE)
+    #     if info:
+    #         return info[0][0]
+    # except socket.gaierror:
+    #     pass
+    if host.startswith("unix://"):
+        return socket.AF_UNIX
+    elif ":" in host and hasattr(socket, "AF_INET6"):
+        return socket.AF_INET6
+    return socket.AF_INET
+
+
+def get_sockaddr(host, port, family):
+    """Return a fully qualified socket address that can be passed to
+    :func:`socket.bind`."""
+    if family == af_unix:
+        return host.split("://", 1)[1]
+    try:
+        res = socket.getaddrinfo(
+            host, port, family, socket.SOCK_STREAM, socket.IPPROTO_TCP
+        )
+    except socket.gaierror:
+        return host, port
+    return res[0][4]
+
+
+class BaseWSGIServer(HTTPServer, object):
+
+    """Simple single-threaded, single-process WSGI server."""
+
+    multithread = False
+    multiprocess = False
+    request_queue_size = LISTEN_QUEUE
+
+    def __init__(
+        self,
+        host,
+        port,
+        app,
+        handler=None,
+        passthrough_errors=False,
+        ssl_context=None,
+        fd=None,
+    ):
+        if handler is None:
+            handler = WSGIRequestHandler
+
+        self.address_family = select_address_family(host, port)
+
+        if fd is not None:
+            real_sock = socket.fromfd(fd, self.address_family, socket.SOCK_STREAM)
+            port = 0
+
+        server_address = get_sockaddr(host, int(port), self.address_family)
+
+        # remove socket file if it already exists
+        if self.address_family == af_unix and os.path.exists(server_address):
+            os.unlink(server_address)
+        HTTPServer.__init__(self, server_address, handler)
+
+        self.app = app
+        self.passthrough_errors = passthrough_errors
+        self.shutdown_signal = False
+        self.host = host
+        self.port = self.socket.getsockname()[1]
+
+        # Patch in the original socket.
+        if fd is not None:
+            self.socket.close()
+            self.socket = real_sock
+            self.server_address = self.socket.getsockname()
+
+        if ssl_context is not None:
+            if isinstance(ssl_context, tuple):
+                ssl_context = load_ssl_context(*ssl_context)
+            if ssl_context == "adhoc":
+                ssl_context = generate_adhoc_ssl_context()
+            # If we are on Python 2 the return value from socket.fromfd
+            # is an internal socket object but what we need for ssl wrap
+            # is the wrapper around it :(
+            sock = self.socket
+            if PY2 and not isinstance(sock, socket.socket):
+                sock = socket.socket(sock.family, sock.type, sock.proto, sock)
+            self.socket = ssl_context.wrap_socket(sock, server_side=True)
+            self.ssl_context = ssl_context
+        else:
+            self.ssl_context = None
+
+    def log(self, type, message, *args):
+        _log(type, message, *args)
+
+    def serve_forever(self):
+        self.shutdown_signal = False
+        try:
+            HTTPServer.serve_forever(self)
+        except KeyboardInterrupt:
+            pass
+        finally:
+            self.server_close()
+
+    def handle_error(self, request, client_address):
+        if self.passthrough_errors:
+            raise
+        # Python 2 still causes a socket.error after the earlier
+        # handling, so silence it here.
+        if isinstance(sys.exc_info()[1], _ConnectionError):
+            return
+        return HTTPServer.handle_error(self, request, client_address)
+
+    def get_request(self):
+        con, info = self.socket.accept()
+        return con, info
+
+
+class ThreadedWSGIServer(ThreadingMixIn, BaseWSGIServer):
+
+    """A WSGI server that does threading."""
+
+    multithread = True
+    daemon_threads = True
+
+
+class ForkingWSGIServer(ForkingMixIn, BaseWSGIServer):
+
+    """A WSGI server that does forking."""
+
+    multiprocess = True
+
+    def __init__(
+        self,
+        host,
+        port,
+        app,
+        processes=40,
+        handler=None,
+        passthrough_errors=False,
+        ssl_context=None,
+        fd=None,
+    ):
+        if not can_fork:
+            raise ValueError("Your platform does not support forking.")
+        BaseWSGIServer.__init__(
+            self, host, port, app, handler, passthrough_errors, ssl_context, fd
+        )
+        self.max_children = processes
+
+
+def make_server(
+    host=None,
+    port=None,
+    app=None,
+    threaded=False,
+    processes=1,
+    request_handler=None,
+    passthrough_errors=False,
+    ssl_context=None,
+    fd=None,
+):
+    """Create a new server instance that is either threaded, or forks
+    or just processes one request after another.
+    """
+    if threaded and processes > 1:
+        raise ValueError("cannot have a multithreaded and multi process server.")
+    elif threaded:
+        return ThreadedWSGIServer(
+            host, port, app, request_handler, passthrough_errors, ssl_context, fd=fd
+        )
+    elif processes > 1:
+        return ForkingWSGIServer(
+            host,
+            port,
+            app,
+            processes,
+            request_handler,
+            passthrough_errors,
+            ssl_context,
+            fd=fd,
+        )
+    else:
+        return BaseWSGIServer(
+            host, port, app, request_handler, passthrough_errors, ssl_context, fd=fd
+        )
+
+
+def is_running_from_reloader():
+    """Checks if the application is running from within the Werkzeug
+    reloader subprocess.
+
+    .. versionadded:: 0.10
+    """
+    return os.environ.get("WERKZEUG_RUN_MAIN") == "true"
+
+
+def run_simple(
+    hostname,
+    port,
+    application,
+    use_reloader=False,
+    use_debugger=False,
+    use_evalex=True,
+    extra_files=None,
+    reloader_interval=1,
+    reloader_type="auto",
+    threaded=False,
+    processes=1,
+    request_handler=None,
+    static_files=None,
+    passthrough_errors=False,
+    ssl_context=None,
+):
+    """Start a WSGI application. Optional features include a reloader,
+    multithreading and fork support.
+
+    This function has a command-line interface too::
+
+        python -m werkzeug.serving --help
+
+    .. versionadded:: 0.5
+       `static_files` was added to simplify serving of static files as well
+       as `passthrough_errors`.
+
+    .. versionadded:: 0.6
+       support for SSL was added.
+
+    .. versionadded:: 0.8
+       Added support for automatically loading a SSL context from certificate
+       file and private key.
+
+    .. versionadded:: 0.9
+       Added command-line interface.
+
+    .. versionadded:: 0.10
+       Improved the reloader and added support for changing the backend
+       through the `reloader_type` parameter.  See :ref:`reloader`
+       for more information.
+
+    .. versionchanged:: 0.15
+        Bind to a Unix socket by passing a path that starts with
+        ``unix://`` as the ``hostname``.
+
+    :param hostname: The host to bind to, for example ``'localhost'``.
+        If the value is a path that starts with ``unix://`` it will bind
+        to a Unix socket instead of a TCP socket..
+    :param port: The port for the server.  eg: ``8080``
+    :param application: the WSGI application to execute
+    :param use_reloader: should the server automatically restart the python
+                         process if modules were changed?
+    :param use_debugger: should the werkzeug debugging system be used?
+    :param use_evalex: should the exception evaluation feature be enabled?
+    :param extra_files: a list of files the reloader should watch
+                        additionally to the modules.  For example configuration
+                        files.
+    :param reloader_interval: the interval for the reloader in seconds.
+    :param reloader_type: the type of reloader to use.  The default is
+                          auto detection.  Valid values are ``'stat'`` and
+                          ``'watchdog'``. See :ref:`reloader` for more
+                          information.
+    :param threaded: should the process handle each request in a separate
+                     thread?
+    :param processes: if greater than 1 then handle each request in a new process
+                      up to this maximum number of concurrent processes.
+    :param request_handler: optional parameter that can be used to replace
+                            the default one.  You can use this to replace it
+                            with a different
+                            :class:`~BaseHTTPServer.BaseHTTPRequestHandler`
+                            subclass.
+    :param static_files: a list or dict of paths for static files.  This works
+                         exactly like :class:`SharedDataMiddleware`, it's actually
+                         just wrapping the application in that middleware before
+                         serving.
+    :param passthrough_errors: set this to `True` to disable the error catching.
+                               This means that the server will die on errors but
+                               it can be useful to hook debuggers in (pdb etc.)
+    :param ssl_context: an SSL context for the connection. Either an
+                        :class:`ssl.SSLContext`, a tuple in the form
+                        ``(cert_file, pkey_file)``, the string ``'adhoc'`` if
+                        the server should automatically create one, or ``None``
+                        to disable SSL (which is the default).
+    """
+    if not isinstance(port, int):
+        raise TypeError("port must be an integer")
+    if use_debugger:
+        from .debug import DebuggedApplication
+
+        application = DebuggedApplication(application, use_evalex)
+    if static_files:
+        from .middleware.shared_data import SharedDataMiddleware
+
+        application = SharedDataMiddleware(application, static_files)
+
+    def log_startup(sock):
+        display_hostname = hostname if hostname not in ("", "*") else "localhost"
+        quit_msg = "(Press CTRL+C to quit)"
+        if sock.family == af_unix:
+            _log("info", " * Running on %s %s", display_hostname, quit_msg)
+        else:
+            if ":" in display_hostname:
+                display_hostname = "[%s]" % display_hostname
+            port = sock.getsockname()[1]
+            _log(
+                "info",
+                " * Running on %s://%s:%d/ %s",
+                "http" if ssl_context is None else "https",
+                display_hostname,
+                port,
+                quit_msg,
+            )
+
+    def inner():
+        try:
+            fd = int(os.environ["WERKZEUG_SERVER_FD"])
+        except (LookupError, ValueError):
+            fd = None
+        srv = make_server(
+            hostname,
+            port,
+            application,
+            threaded,
+            processes,
+            request_handler,
+            passthrough_errors,
+            ssl_context,
+            fd=fd,
+        )
+        if fd is None:
+            log_startup(srv.socket)
+        srv.serve_forever()
+
+    if use_reloader:
+        # If we're not running already in the subprocess that is the
+        # reloader we want to open up a socket early to make sure the
+        # port is actually available.
+        if not is_running_from_reloader():
+            if port == 0 and not can_open_by_fd:
+                raise ValueError(
+                    "Cannot bind to a random port with enabled "
+                    "reloader if the Python interpreter does "
+                    "not support socket opening by fd."
+                )
+
+            # Create and destroy a socket so that any exceptions are
+            # raised before we spawn a separate Python interpreter and
+            # lose this ability.
+            address_family = select_address_family(hostname, port)
+            server_address = get_sockaddr(hostname, port, address_family)
+            s = socket.socket(address_family, socket.SOCK_STREAM)
+            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            s.bind(server_address)
+            if hasattr(s, "set_inheritable"):
+                s.set_inheritable(True)
+
+            # If we can open the socket by file descriptor, then we can just
+            # reuse this one and our socket will survive the restarts.
+            if can_open_by_fd:
+                os.environ["WERKZEUG_SERVER_FD"] = str(s.fileno())
+                s.listen(LISTEN_QUEUE)
+                log_startup(s)
+            else:
+                s.close()
+                if address_family == af_unix:
+                    _log("info", "Unlinking %s" % server_address)
+                    os.unlink(server_address)
+
+        # Do not use relative imports, otherwise "python -m werkzeug.serving"
+        # breaks.
+        from ._reloader import run_with_reloader
+
+        run_with_reloader(inner, extra_files, reloader_interval, reloader_type)
+    else:
+        inner()
+
+
+def run_with_reloader(*args, **kwargs):
+    # People keep using undocumented APIs.  Do not use this function
+    # please, we do not guarantee that it continues working.
+    from ._reloader import run_with_reloader
+
+    return run_with_reloader(*args, **kwargs)
+
+
+def main():
+    """A simple command-line interface for :py:func:`run_simple`."""
+
+    # in contrast to argparse, this works at least under Python < 2.7
+    import optparse
+    from .utils import import_string
+
+    parser = optparse.OptionParser(usage="Usage: %prog [options] app_module:app_object")
+    parser.add_option(
+        "-b",
+        "--bind",
+        dest="address",
+        help="The hostname:port the app should listen on.",
+    )
+    parser.add_option(
+        "-d",
+        "--debug",
+        dest="use_debugger",
+        action="store_true",
+        default=False,
+        help="Use Werkzeug's debugger.",
+    )
+    parser.add_option(
+        "-r",
+        "--reload",
+        dest="use_reloader",
+        action="store_true",
+        default=False,
+        help="Reload Python process if modules change.",
+    )
+    options, args = parser.parse_args()
+
+    hostname, port = None, None
+    if options.address:
+        address = options.address.split(":")
+        hostname = address[0]
+        if len(address) > 1:
+            port = address[1]
+
+    if len(args) != 1:
+        sys.stdout.write("No application supplied, or too much. See --help\n")
+        sys.exit(1)
+    app = import_string(args[0])
+
+    run_simple(
+        hostname=(hostname or "127.0.0.1"),
+        port=int(port or 5000),
+        application=app,
+        use_reloader=options.use_reloader,
+        use_debugger=options.use_debugger,
+    )
+
+
+if __name__ == "__main__":
+    main()
diff --git a/python/werkzeug/test.py b/python/werkzeug/test.py
new file mode 100644
index 0000000..6148665
--- /dev/null
+++ b/python/werkzeug/test.py
@@ -0,0 +1,1146 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.test
+    ~~~~~~~~~~~~~
+
+    This module implements a client to WSGI applications for testing.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import mimetypes
+import sys
+from io import BytesIO
+from itertools import chain
+from random import random
+from tempfile import TemporaryFile
+from time import time
+
+from ._compat import iteritems
+from ._compat import iterlists
+from ._compat import itervalues
+from ._compat import make_literal_wrapper
+from ._compat import reraise
+from ._compat import string_types
+from ._compat import text_type
+from ._compat import to_bytes
+from ._compat import wsgi_encoding_dance
+from ._internal import _get_environ
+from .datastructures import CallbackDict
+from .datastructures import CombinedMultiDict
+from .datastructures import EnvironHeaders
+from .datastructures import FileMultiDict
+from .datastructures import FileStorage
+from .datastructures import Headers
+from .datastructures import MultiDict
+from .http import dump_cookie
+from .http import dump_options_header
+from .http import parse_options_header
+from .urls import iri_to_uri
+from .urls import url_encode
+from .urls import url_fix
+from .urls import url_parse
+from .urls import url_unparse
+from .urls import url_unquote
+from .utils import get_content_type
+from .wrappers import BaseRequest
+from .wsgi import ClosingIterator
+from .wsgi import get_current_url
+
+try:
+    from urllib.request import Request as U2Request
+except ImportError:
+    from urllib2 import Request as U2Request
+
+try:
+    from http.cookiejar import CookieJar
+except ImportError:
+    from cookielib import CookieJar
+
+
+def stream_encode_multipart(
+    values, use_tempfile=True, threshold=1024 * 500, boundary=None, charset="utf-8"
+):
+    """Encode a dict of values (either strings or file descriptors or
+    :class:`FileStorage` objects.) into a multipart encoded string stored
+    in a file descriptor.
+    """
+    if boundary is None:
+        boundary = "---------------WerkzeugFormPart_%s%s" % (time(), random())
+    _closure = [BytesIO(), 0, False]
+
+    if use_tempfile:
+
+        def write_binary(string):
+            stream, total_length, on_disk = _closure
+            if on_disk:
+                stream.write(string)
+            else:
+                length = len(string)
+                if length + _closure[1] <= threshold:
+                    stream.write(string)
+                else:
+                    new_stream = TemporaryFile("wb+")
+                    new_stream.write(stream.getvalue())
+                    new_stream.write(string)
+                    _closure[0] = new_stream
+                    _closure[2] = True
+                _closure[1] = total_length + length
+
+    else:
+        write_binary = _closure[0].write
+
+    def write(string):
+        write_binary(string.encode(charset))
+
+    if not isinstance(values, MultiDict):
+        values = MultiDict(values)
+
+    for key, values in iterlists(values):
+        for value in values:
+            write('--%s\r\nContent-Disposition: form-data; name="%s"' % (boundary, key))
+            reader = getattr(value, "read", None)
+            if reader is not None:
+                filename = getattr(value, "filename", getattr(value, "name", None))
+                content_type = getattr(value, "content_type", None)
+                if content_type is None:
+                    content_type = (
+                        filename
+                        and mimetypes.guess_type(filename)[0]
+                        or "application/octet-stream"
+                    )
+                if filename is not None:
+                    write('; filename="%s"\r\n' % filename)
+                else:
+                    write("\r\n")
+                write("Content-Type: %s\r\n\r\n" % content_type)
+                while 1:
+                    chunk = reader(16384)
+                    if not chunk:
+                        break
+                    write_binary(chunk)
+            else:
+                if not isinstance(value, string_types):
+                    value = str(value)
+
+                value = to_bytes(value, charset)
+                write("\r\n\r\n")
+                write_binary(value)
+            write("\r\n")
+    write("--%s--\r\n" % boundary)
+
+    length = int(_closure[0].tell())
+    _closure[0].seek(0)
+    return _closure[0], length, boundary
+
+
+def encode_multipart(values, boundary=None, charset="utf-8"):
+    """Like `stream_encode_multipart` but returns a tuple in the form
+    (``boundary``, ``data``) where data is a bytestring.
+    """
+    stream, length, boundary = stream_encode_multipart(
+        values, use_tempfile=False, boundary=boundary, charset=charset
+    )
+    return boundary, stream.read()
+
+
+def File(fd, filename=None, mimetype=None):
+    """Backwards compat.
+
+    .. deprecated:: 0.5
+    """
+    from warnings import warn
+
+    warn(
+        "'werkzeug.test.File' is deprecated as of version 0.5 and will"
+        " be removed in version 1.0. Use 'EnvironBuilder' or"
+        " 'FileStorage' instead.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    return FileStorage(fd, filename=filename, content_type=mimetype)
+
+
+class _TestCookieHeaders(object):
+
+    """A headers adapter for cookielib
+    """
+
+    def __init__(self, headers):
+        self.headers = headers
+
+    def getheaders(self, name):
+        headers = []
+        name = name.lower()
+        for k, v in self.headers:
+            if k.lower() == name:
+                headers.append(v)
+        return headers
+
+    def get_all(self, name, default=None):
+        rv = []
+        for k, v in self.headers:
+            if k.lower() == name.lower():
+                rv.append(v)
+        return rv or default or []
+
+
+class _TestCookieResponse(object):
+
+    """Something that looks like a httplib.HTTPResponse, but is actually just an
+    adapter for our test responses to make them available for cookielib.
+    """
+
+    def __init__(self, headers):
+        self.headers = _TestCookieHeaders(headers)
+
+    def info(self):
+        return self.headers
+
+
+class _TestCookieJar(CookieJar):
+
+    """A cookielib.CookieJar modified to inject and read cookie headers from
+    and to wsgi environments, and wsgi application responses.
+    """
+
+    def inject_wsgi(self, environ):
+        """Inject the cookies as client headers into the server's wsgi
+        environment.
+        """
+        cvals = ["%s=%s" % (c.name, c.value) for c in self]
+
+        if cvals:
+            environ["HTTP_COOKIE"] = "; ".join(cvals)
+        else:
+            environ.pop("HTTP_COOKIE", None)
+
+    def extract_wsgi(self, environ, headers):
+        """Extract the server's set-cookie headers as cookies into the
+        cookie jar.
+        """
+        self.extract_cookies(
+            _TestCookieResponse(headers), U2Request(get_current_url(environ))
+        )
+
+
+def _iter_data(data):
+    """Iterates over a `dict` or :class:`MultiDict` yielding all keys and
+    values.
+    This is used to iterate over the data passed to the
+    :class:`EnvironBuilder`.
+    """
+    if isinstance(data, MultiDict):
+        for key, values in iterlists(data):
+            for value in values:
+                yield key, value
+    else:
+        for key, values in iteritems(data):
+            if isinstance(values, list):
+                for value in values:
+                    yield key, value
+            else:
+                yield key, values
+
+
+class EnvironBuilder(object):
+    """This class can be used to conveniently create a WSGI environment
+    for testing purposes.  It can be used to quickly create WSGI environments
+    or request objects from arbitrary data.
+
+    The signature of this class is also used in some other places as of
+    Werkzeug 0.5 (:func:`create_environ`, :meth:`BaseResponse.from_values`,
+    :meth:`Client.open`).  Because of this most of the functionality is
+    available through the constructor alone.
+
+    Files and regular form data can be manipulated independently of each
+    other with the :attr:`form` and :attr:`files` attributes, but are
+    passed with the same argument to the constructor: `data`.
+
+    `data` can be any of these values:
+
+    -   a `str` or `bytes` object: The object is converted into an
+        :attr:`input_stream`, the :attr:`content_length` is set and you have to
+        provide a :attr:`content_type`.
+    -   a `dict` or :class:`MultiDict`: The keys have to be strings. The values
+        have to be either any of the following objects, or a list of any of the
+        following objects:
+
+        -   a :class:`file`-like object:  These are converted into
+            :class:`FileStorage` objects automatically.
+        -   a `tuple`:  The :meth:`~FileMultiDict.add_file` method is called
+            with the key and the unpacked `tuple` items as positional
+            arguments.
+        -   a `str`:  The string is set as form data for the associated key.
+    -   a file-like object: The object content is loaded in memory and then
+        handled like a regular `str` or a `bytes`.
+
+    :param path: the path of the request.  In the WSGI environment this will
+                 end up as `PATH_INFO`.  If the `query_string` is not defined
+                 and there is a question mark in the `path` everything after
+                 it is used as query string.
+    :param base_url: the base URL is a URL that is used to extract the WSGI
+                     URL scheme, host (server name + server port) and the
+                     script root (`SCRIPT_NAME`).
+    :param query_string: an optional string or dict with URL parameters.
+    :param method: the HTTP method to use, defaults to `GET`.
+    :param input_stream: an optional input stream.  Do not specify this and
+                         `data`.  As soon as an input stream is set you can't
+                         modify :attr:`args` and :attr:`files` unless you
+                         set the :attr:`input_stream` to `None` again.
+    :param content_type: The content type for the request.  As of 0.5 you
+                         don't have to provide this when specifying files
+                         and form data via `data`.
+    :param content_length: The content length for the request.  You don't
+                           have to specify this when providing data via
+                           `data`.
+    :param errors_stream: an optional error stream that is used for
+                          `wsgi.errors`.  Defaults to :data:`stderr`.
+    :param multithread: controls `wsgi.multithread`.  Defaults to `False`.
+    :param multiprocess: controls `wsgi.multiprocess`.  Defaults to `False`.
+    :param run_once: controls `wsgi.run_once`.  Defaults to `False`.
+    :param headers: an optional list or :class:`Headers` object of headers.
+    :param data: a string or dict of form data or a file-object.
+                 See explanation above.
+    :param json: An object to be serialized and assigned to ``data``.
+        Defaults the content type to ``"application/json"``.
+        Serialized with the function assigned to :attr:`json_dumps`.
+    :param environ_base: an optional dict of environment defaults.
+    :param environ_overrides: an optional dict of environment overrides.
+    :param charset: the charset used to encode unicode data.
+
+    .. versionadded:: 0.15
+        The ``json`` param and :meth:`json_dumps` method.
+
+    .. versionadded:: 0.15
+        The environ has keys ``REQUEST_URI`` and ``RAW_URI`` containing
+        the path before perecent-decoding. This is not part of the WSGI
+        PEP, but many WSGI servers include it.
+
+    .. versionchanged:: 0.6
+       ``path`` and ``base_url`` can now be unicode strings that are
+       encoded with :func:`iri_to_uri`.
+    """
+
+    #: the server protocol to use.  defaults to HTTP/1.1
+    server_protocol = "HTTP/1.1"
+
+    #: the wsgi version to use.  defaults to (1, 0)
+    wsgi_version = (1, 0)
+
+    #: the default request class for :meth:`get_request`
+    request_class = BaseRequest
+
+    import json
+
+    #: The serialization function used when ``json`` is passed.
+    json_dumps = staticmethod(json.dumps)
+    del json
+
+    def __init__(
+        self,
+        path="/",
+        base_url=None,
+        query_string=None,
+        method="GET",
+        input_stream=None,
+        content_type=None,
+        content_length=None,
+        errors_stream=None,
+        multithread=False,
+        multiprocess=False,
+        run_once=False,
+        headers=None,
+        data=None,
+        environ_base=None,
+        environ_overrides=None,
+        charset="utf-8",
+        mimetype=None,
+        json=None,
+    ):
+        path_s = make_literal_wrapper(path)
+        if query_string is not None and path_s("?") in path:
+            raise ValueError("Query string is defined in the path and as an argument")
+        if query_string is None and path_s("?") in path:
+            path, query_string = path.split(path_s("?"), 1)
+        self.charset = charset
+        self.path = iri_to_uri(path)
+        if base_url is not None:
+            base_url = url_fix(iri_to_uri(base_url, charset), charset)
+        self.base_url = base_url
+        if isinstance(query_string, (bytes, text_type)):
+            self.query_string = query_string
+        else:
+            if query_string is None:
+                query_string = MultiDict()
+            elif not isinstance(query_string, MultiDict):
+                query_string = MultiDict(query_string)
+            self.args = query_string
+        self.method = method
+        if headers is None:
+            headers = Headers()
+        elif not isinstance(headers, Headers):
+            headers = Headers(headers)
+        self.headers = headers
+        if content_type is not None:
+            self.content_type = content_type
+        if errors_stream is None:
+            errors_stream = sys.stderr
+        self.errors_stream = errors_stream
+        self.multithread = multithread
+        self.multiprocess = multiprocess
+        self.run_once = run_once
+        self.environ_base = environ_base
+        self.environ_overrides = environ_overrides
+        self.input_stream = input_stream
+        self.content_length = content_length
+        self.closed = False
+
+        if json is not None:
+            if data is not None:
+                raise TypeError("can't provide both json and data")
+
+            data = self.json_dumps(json)
+
+            if self.content_type is None:
+                self.content_type = "application/json"
+
+        if data:
+            if input_stream is not None:
+                raise TypeError("can't provide input stream and data")
+            if hasattr(data, "read"):
+                data = data.read()
+            if isinstance(data, text_type):
+                data = data.encode(self.charset)
+            if isinstance(data, bytes):
+                self.input_stream = BytesIO(data)
+                if self.content_length is None:
+                    self.content_length = len(data)
+            else:
+                for key, value in _iter_data(data):
+                    if isinstance(value, (tuple, dict)) or hasattr(value, "read"):
+                        self._add_file_from_data(key, value)
+                    else:
+                        self.form.setlistdefault(key).append(value)
+
+        if mimetype is not None:
+            self.mimetype = mimetype
+
+    @classmethod
+    def from_environ(cls, environ, **kwargs):
+        """Turn an environ dict back into a builder. Any extra kwargs
+        override the args extracted from the environ.
+
+        .. versionadded:: 0.15
+        """
+        headers = Headers(EnvironHeaders(environ))
+        out = {
+            "path": environ["PATH_INFO"],
+            "base_url": cls._make_base_url(
+                environ["wsgi.url_scheme"], headers.pop("Host"), environ["SCRIPT_NAME"]
+            ),
+            "query_string": environ["QUERY_STRING"],
+            "method": environ["REQUEST_METHOD"],
+            "input_stream": environ["wsgi.input"],
+            "content_type": headers.pop("Content-Type", None),
+            "content_length": headers.pop("Content-Length", None),
+            "errors_stream": environ["wsgi.errors"],
+            "multithread": environ["wsgi.multithread"],
+            "multiprocess": environ["wsgi.multiprocess"],
+            "run_once": environ["wsgi.run_once"],
+            "headers": headers,
+        }
+        out.update(kwargs)
+        return cls(**out)
+
+    def _add_file_from_data(self, key, value):
+        """Called in the EnvironBuilder to add files from the data dict."""
+        if isinstance(value, tuple):
+            self.files.add_file(key, *value)
+        elif isinstance(value, dict):
+            from warnings import warn
+
+            warn(
+                "Passing a dict as file data is deprecated as of"
+                " version 0.5 and will be removed in version 1.0. Use"
+                " a tuple or 'FileStorage' object instead.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            value = dict(value)
+            mimetype = value.pop("mimetype", None)
+            if mimetype is not None:
+                value["content_type"] = mimetype
+            self.files.add_file(key, **value)
+        else:
+            self.files.add_file(key, value)
+
+    @staticmethod
+    def _make_base_url(scheme, host, script_root):
+        return url_unparse((scheme, host, script_root, "", "")).rstrip("/") + "/"
+
+    @property
+    def base_url(self):
+        """The base URL is used to extract the URL scheme, host name,
+        port, and root path.
+        """
+        return self._make_base_url(self.url_scheme, self.host, self.script_root)
+
+    @base_url.setter
+    def base_url(self, value):
+        if value is None:
+            scheme = "http"
+            netloc = "localhost"
+            script_root = ""
+        else:
+            scheme, netloc, script_root, qs, anchor = url_parse(value)
+            if qs or anchor:
+                raise ValueError("base url must not contain a query string or fragment")
+        self.script_root = script_root.rstrip("/")
+        self.host = netloc
+        self.url_scheme = scheme
+
+    def _get_content_type(self):
+        ct = self.headers.get("Content-Type")
+        if ct is None and not self._input_stream:
+            if self._files:
+                return "multipart/form-data"
+            elif self._form:
+                return "application/x-www-form-urlencoded"
+            return None
+        return ct
+
+    def _set_content_type(self, value):
+        if value is None:
+            self.headers.pop("Content-Type", None)
+        else:
+            self.headers["Content-Type"] = value
+
+    content_type = property(
+        _get_content_type,
+        _set_content_type,
+        doc="""The content type for the request.  Reflected from and to
+        the :attr:`headers`.  Do not set if you set :attr:`files` or
+        :attr:`form` for auto detection.""",
+    )
+    del _get_content_type, _set_content_type
+
+    def _get_content_length(self):
+        return self.headers.get("Content-Length", type=int)
+
+    def _get_mimetype(self):
+        ct = self.content_type
+        if ct:
+            return ct.split(";")[0].strip()
+
+    def _set_mimetype(self, value):
+        self.content_type = get_content_type(value, self.charset)
+
+    def _get_mimetype_params(self):
+        def on_update(d):
+            self.headers["Content-Type"] = dump_options_header(self.mimetype, d)
+
+        d = parse_options_header(self.headers.get("content-type", ""))[1]
+        return CallbackDict(d, on_update)
+
+    mimetype = property(
+        _get_mimetype,
+        _set_mimetype,
+        doc="""The mimetype (content type without charset etc.)
+
+        .. versionadded:: 0.14
+    """,
+    )
+    mimetype_params = property(
+        _get_mimetype_params,
+        doc=""" The mimetype parameters as dict.  For example if the
+        content type is ``text/html; charset=utf-8`` the params would be
+        ``{'charset': 'utf-8'}``.
+
+        .. versionadded:: 0.14
+        """,
+    )
+    del _get_mimetype, _set_mimetype, _get_mimetype_params
+
+    def _set_content_length(self, value):
+        if value is None:
+            self.headers.pop("Content-Length", None)
+        else:
+            self.headers["Content-Length"] = str(value)
+
+    content_length = property(
+        _get_content_length,
+        _set_content_length,
+        doc="""The content length as integer.  Reflected from and to the
+        :attr:`headers`.  Do not set if you set :attr:`files` or
+        :attr:`form` for auto detection.""",
+    )
+    del _get_content_length, _set_content_length
+
+    def form_property(name, storage, doc):  # noqa: B902
+        key = "_" + name
+
+        def getter(self):
+            if self._input_stream is not None:
+                raise AttributeError("an input stream is defined")
+            rv = getattr(self, key)
+            if rv is None:
+                rv = storage()
+                setattr(self, key, rv)
+
+            return rv
+
+        def setter(self, value):
+            self._input_stream = None
+            setattr(self, key, value)
+
+        return property(getter, setter, doc=doc)
+
+    form = form_property("form", MultiDict, doc="A :class:`MultiDict` of form values.")
+    files = form_property(
+        "files",
+        FileMultiDict,
+        doc="""A :class:`FileMultiDict` of uploaded files.  You can use
+        the :meth:`~FileMultiDict.add_file` method to add new files to
+        the dict.""",
+    )
+    del form_property
+
+    def _get_input_stream(self):
+        return self._input_stream
+
+    def _set_input_stream(self, value):
+        self._input_stream = value
+        self._form = self._files = None
+
+    input_stream = property(
+        _get_input_stream,
+        _set_input_stream,
+        doc="""An optional input stream.  If you set this it will clear
+        :attr:`form` and :attr:`files`.""",
+    )
+    del _get_input_stream, _set_input_stream
+
+    def _get_query_string(self):
+        if self._query_string is None:
+            if self._args is not None:
+                return url_encode(self._args, charset=self.charset)
+            return ""
+        return self._query_string
+
+    def _set_query_string(self, value):
+        self._query_string = value
+        self._args = None
+
+    query_string = property(
+        _get_query_string,
+        _set_query_string,
+        doc="""The query string.  If you set this to a string
+        :attr:`args` will no longer be available.""",
+    )
+    del _get_query_string, _set_query_string
+
+    def _get_args(self):
+        if self._query_string is not None:
+            raise AttributeError("a query string is defined")
+        if self._args is None:
+            self._args = MultiDict()
+        return self._args
+
+    def _set_args(self, value):
+        self._query_string = None
+        self._args = value
+
+    args = property(
+        _get_args, _set_args, doc="The URL arguments as :class:`MultiDict`."
+    )
+    del _get_args, _set_args
+
+    @property
+    def server_name(self):
+        """The server name (read-only, use :attr:`host` to set)"""
+        return self.host.split(":", 1)[0]
+
+    @property
+    def server_port(self):
+        """The server port as integer (read-only, use :attr:`host` to set)"""
+        pieces = self.host.split(":", 1)
+        if len(pieces) == 2 and pieces[1].isdigit():
+            return int(pieces[1])
+        elif self.url_scheme == "https":
+            return 443
+        return 80
+
+    def __del__(self):
+        try:
+            self.close()
+        except Exception:
+            pass
+
+    def close(self):
+        """Closes all files.  If you put real :class:`file` objects into the
+        :attr:`files` dict you can call this method to automatically close
+        them all in one go.
+        """
+        if self.closed:
+            return
+        try:
+            files = itervalues(self.files)
+        except AttributeError:
+            files = ()
+        for f in files:
+            try:
+                f.close()
+            except Exception:
+                pass
+        self.closed = True
+
+    def get_environ(self):
+        """Return the built environ.
+
+        .. versionchanged:: 0.15
+            The content type and length headers are set based on
+            input stream detection. Previously this only set the WSGI
+            keys.
+        """
+        input_stream = self.input_stream
+        content_length = self.content_length
+
+        mimetype = self.mimetype
+        content_type = self.content_type
+
+        if input_stream is not None:
+            start_pos = input_stream.tell()
+            input_stream.seek(0, 2)
+            end_pos = input_stream.tell()
+            input_stream.seek(start_pos)
+            content_length = end_pos - start_pos
+        elif mimetype == "multipart/form-data":
+            values = CombinedMultiDict([self.form, self.files])
+            input_stream, content_length, boundary = stream_encode_multipart(
+                values, charset=self.charset
+            )
+            content_type = mimetype + '; boundary="%s"' % boundary
+        elif mimetype == "application/x-www-form-urlencoded":
+            # XXX: py2v3 review
+            values = url_encode(self.form, charset=self.charset)
+            values = values.encode("ascii")
+            content_length = len(values)
+            input_stream = BytesIO(values)
+        else:
+            input_stream = BytesIO()
+
+        result = {}
+        if self.environ_base:
+            result.update(self.environ_base)
+
+        def _path_encode(x):
+            return wsgi_encoding_dance(url_unquote(x, self.charset), self.charset)
+
+        qs = wsgi_encoding_dance(self.query_string)
+
+        result.update(
+            {
+                "REQUEST_METHOD": self.method,
+                "SCRIPT_NAME": _path_encode(self.script_root),
+                "PATH_INFO": _path_encode(self.path),
+                "QUERY_STRING": qs,
+                # Non-standard, added by mod_wsgi, uWSGI
+                "REQUEST_URI": wsgi_encoding_dance(self.path),
+                # Non-standard, added by gunicorn
+                "RAW_URI": wsgi_encoding_dance(self.path),
+                "SERVER_NAME": self.server_name,
+                "SERVER_PORT": str(self.server_port),
+                "HTTP_HOST": self.host,
+                "SERVER_PROTOCOL": self.server_protocol,
+                "wsgi.version": self.wsgi_version,
+                "wsgi.url_scheme": self.url_scheme,
+                "wsgi.input": input_stream,
+                "wsgi.errors": self.errors_stream,
+                "wsgi.multithread": self.multithread,
+                "wsgi.multiprocess": self.multiprocess,
+                "wsgi.run_once": self.run_once,
+            }
+        )
+
+        headers = self.headers.copy()
+
+        if content_type is not None:
+            result["CONTENT_TYPE"] = content_type
+            headers.set("Content-Type", content_type)
+
+        if content_length is not None:
+            result["CONTENT_LENGTH"] = str(content_length)
+            headers.set("Content-Length", content_length)
+
+        for key, value in headers.to_wsgi_list():
+            result["HTTP_%s" % key.upper().replace("-", "_")] = value
+
+        if self.environ_overrides:
+            result.update(self.environ_overrides)
+
+        return result
+
+    def get_request(self, cls=None):
+        """Returns a request with the data.  If the request class is not
+        specified :attr:`request_class` is used.
+
+        :param cls: The request wrapper to use.
+        """
+        if cls is None:
+            cls = self.request_class
+        return cls(self.get_environ())
+
+
+class ClientRedirectError(Exception):
+    """If a redirect loop is detected when using follow_redirects=True with
+    the :cls:`Client`, then this exception is raised.
+    """
+
+
+class Client(object):
+    """This class allows you to send requests to a wrapped application.
+
+    The response wrapper can be a class or factory function that takes
+    three arguments: app_iter, status and headers.  The default response
+    wrapper just returns a tuple.
+
+    Example::
+
+        class ClientResponse(BaseResponse):
+            ...
+
+        client = Client(MyApplication(), response_wrapper=ClientResponse)
+
+    The use_cookies parameter indicates whether cookies should be stored and
+    sent for subsequent requests. This is True by default, but passing False
+    will disable this behaviour.
+
+    If you want to request some subdomain of your application you may set
+    `allow_subdomain_redirects` to `True` as if not no external redirects
+    are allowed.
+
+    .. versionadded:: 0.5
+       `use_cookies` is new in this version.  Older versions did not provide
+       builtin cookie support.
+
+    .. versionadded:: 0.14
+       The `mimetype` parameter was added.
+
+    .. versionadded:: 0.15
+        The ``json`` parameter.
+    """
+
+    def __init__(
+        self,
+        application,
+        response_wrapper=None,
+        use_cookies=True,
+        allow_subdomain_redirects=False,
+    ):
+        self.application = application
+        self.response_wrapper = response_wrapper
+        if use_cookies:
+            self.cookie_jar = _TestCookieJar()
+        else:
+            self.cookie_jar = None
+        self.allow_subdomain_redirects = allow_subdomain_redirects
+
+    def set_cookie(
+        self,
+        server_name,
+        key,
+        value="",
+        max_age=None,
+        expires=None,
+        path="/",
+        domain=None,
+        secure=None,
+        httponly=False,
+        charset="utf-8",
+    ):
+        """Sets a cookie in the client's cookie jar.  The server name
+        is required and has to match the one that is also passed to
+        the open call.
+        """
+        assert self.cookie_jar is not None, "cookies disabled"
+        header = dump_cookie(
+            key, value, max_age, expires, path, domain, secure, httponly, charset
+        )
+        environ = create_environ(path, base_url="http://" + server_name)
+        headers = [("Set-Cookie", header)]
+        self.cookie_jar.extract_wsgi(environ, headers)
+
+    def delete_cookie(self, server_name, key, path="/", domain=None):
+        """Deletes a cookie in the test client."""
+        self.set_cookie(
+            server_name, key, expires=0, max_age=0, path=path, domain=domain
+        )
+
+    def run_wsgi_app(self, environ, buffered=False):
+        """Runs the wrapped WSGI app with the given environment."""
+        if self.cookie_jar is not None:
+            self.cookie_jar.inject_wsgi(environ)
+        rv = run_wsgi_app(self.application, environ, buffered=buffered)
+        if self.cookie_jar is not None:
+            self.cookie_jar.extract_wsgi(environ, rv[2])
+        return rv
+
+    def resolve_redirect(self, response, new_location, environ, buffered=False):
+        """Perform a new request to the location given by the redirect
+        response to the previous request.
+        """
+        scheme, netloc, path, qs, anchor = url_parse(new_location)
+        builder = EnvironBuilder.from_environ(environ, query_string=qs)
+
+        to_name_parts = netloc.split(":", 1)[0].split(".")
+        from_name_parts = builder.server_name.split(".")
+
+        if to_name_parts != [""]:
+            # The new location has a host, use it for the base URL.
+            builder.url_scheme = scheme
+            builder.host = netloc
+        else:
+            # A local redirect with autocorrect_location_header=False
+            # doesn't have a host, so use the request's host.
+            to_name_parts = from_name_parts
+
+        # Explain why a redirect to a different server name won't be followed.
+        if to_name_parts != from_name_parts:
+            if to_name_parts[-len(from_name_parts) :] == from_name_parts:
+                if not self.allow_subdomain_redirects:
+                    raise RuntimeError("Following subdomain redirects is not enabled.")
+            else:
+                raise RuntimeError("Following external redirects is not supported.")
+
+        path_parts = path.split("/")
+        root_parts = builder.script_root.split("/")
+
+        if path_parts[: len(root_parts)] == root_parts:
+            # Strip the script root from the path.
+            builder.path = path[len(builder.script_root) :]
+        else:
+            # The new location is not under the script root, so use the
+            # whole path and clear the previous root.
+            builder.path = path
+            builder.script_root = ""
+
+        status_code = int(response[1].split(None, 1)[0])
+
+        # Only 307 and 308 preserve all of the original request.
+        if status_code not in {307, 308}:
+            # HEAD is preserved, everything else becomes GET.
+            if builder.method != "HEAD":
+                builder.method = "GET"
+
+            # Clear the body and the headers that describe it.
+            builder.input_stream = None
+            builder.content_type = None
+            builder.content_length = None
+            builder.headers.pop("Transfer-Encoding", None)
+
+        # Disable the response wrapper while handling redirects. Not
+        # thread safe, but the client should not be shared anyway.
+        old_response_wrapper = self.response_wrapper
+        self.response_wrapper = None
+
+        try:
+            return self.open(builder, as_tuple=True, buffered=buffered)
+        finally:
+            self.response_wrapper = old_response_wrapper
+
+    def open(self, *args, **kwargs):
+        """Takes the same arguments as the :class:`EnvironBuilder` class with
+        some additions:  You can provide a :class:`EnvironBuilder` or a WSGI
+        environment as only argument instead of the :class:`EnvironBuilder`
+        arguments and two optional keyword arguments (`as_tuple`, `buffered`)
+        that change the type of the return value or the way the application is
+        executed.
+
+        .. versionchanged:: 0.5
+           If a dict is provided as file in the dict for the `data` parameter
+           the content type has to be called `content_type` now instead of
+           `mimetype`.  This change was made for consistency with
+           :class:`werkzeug.FileWrapper`.
+
+            The `follow_redirects` parameter was added to :func:`open`.
+
+        Additional parameters:
+
+        :param as_tuple: Returns a tuple in the form ``(environ, result)``
+        :param buffered: Set this to True to buffer the application run.
+                         This will automatically close the application for
+                         you as well.
+        :param follow_redirects: Set this to True if the `Client` should
+                                 follow HTTP redirects.
+        """
+        as_tuple = kwargs.pop("as_tuple", False)
+        buffered = kwargs.pop("buffered", False)
+        follow_redirects = kwargs.pop("follow_redirects", False)
+        environ = None
+        if not kwargs and len(args) == 1:
+            if isinstance(args[0], EnvironBuilder):
+                environ = args[0].get_environ()
+            elif isinstance(args[0], dict):
+                environ = args[0]
+        if environ is None:
+            builder = EnvironBuilder(*args, **kwargs)
+            try:
+                environ = builder.get_environ()
+            finally:
+                builder.close()
+
+        response = self.run_wsgi_app(environ.copy(), buffered=buffered)
+
+        # handle redirects
+        redirect_chain = []
+        while 1:
+            status_code = int(response[1].split(None, 1)[0])
+            if (
+                status_code not in {301, 302, 303, 305, 307, 308}
+                or not follow_redirects
+            ):
+                break
+
+            # Exhaust intermediate response bodies to ensure middleware
+            # that returns an iterator runs any cleanup code.
+            if not buffered:
+                for _ in response[0]:
+                    pass
+
+            new_location = response[2]["location"]
+            new_redirect_entry = (new_location, status_code)
+            if new_redirect_entry in redirect_chain:
+                raise ClientRedirectError("loop detected")
+            redirect_chain.append(new_redirect_entry)
+            environ, response = self.resolve_redirect(
+                response, new_location, environ, buffered=buffered
+            )
+
+        if self.response_wrapper is not None:
+            response = self.response_wrapper(*response)
+        if as_tuple:
+            return environ, response
+        return response
+
+    def get(self, *args, **kw):
+        """Like open but method is enforced to GET."""
+        kw["method"] = "GET"
+        return self.open(*args, **kw)
+
+    def patch(self, *args, **kw):
+        """Like open but method is enforced to PATCH."""
+        kw["method"] = "PATCH"
+        return self.open(*args, **kw)
+
+    def post(self, *args, **kw):
+        """Like open but method is enforced to POST."""
+        kw["method"] = "POST"
+        return self.open(*args, **kw)
+
+    def head(self, *args, **kw):
+        """Like open but method is enforced to HEAD."""
+        kw["method"] = "HEAD"
+        return self.open(*args, **kw)
+
+    def put(self, *args, **kw):
+        """Like open but method is enforced to PUT."""
+        kw["method"] = "PUT"
+        return self.open(*args, **kw)
+
+    def delete(self, *args, **kw):
+        """Like open but method is enforced to DELETE."""
+        kw["method"] = "DELETE"
+        return self.open(*args, **kw)
+
+    def options(self, *args, **kw):
+        """Like open but method is enforced to OPTIONS."""
+        kw["method"] = "OPTIONS"
+        return self.open(*args, **kw)
+
+    def trace(self, *args, **kw):
+        """Like open but method is enforced to TRACE."""
+        kw["method"] = "TRACE"
+        return self.open(*args, **kw)
+
+    def __repr__(self):
+        return "<%s %r>" % (self.__class__.__name__, self.application)
+
+
+def create_environ(*args, **kwargs):
+    """Create a new WSGI environ dict based on the values passed.  The first
+    parameter should be the path of the request which defaults to '/'.  The
+    second one can either be an absolute path (in that case the host is
+    localhost:80) or a full path to the request with scheme, netloc port and
+    the path to the script.
+
+    This accepts the same arguments as the :class:`EnvironBuilder`
+    constructor.
+
+    .. versionchanged:: 0.5
+       This function is now a thin wrapper over :class:`EnvironBuilder` which
+       was added in 0.5.  The `headers`, `environ_base`, `environ_overrides`
+       and `charset` parameters were added.
+    """
+    builder = EnvironBuilder(*args, **kwargs)
+    try:
+        return builder.get_environ()
+    finally:
+        builder.close()
+
+
+def run_wsgi_app(app, environ, buffered=False):
+    """Return a tuple in the form (app_iter, status, headers) of the
+    application output.  This works best if you pass it an application that
+    returns an iterator all the time.
+
+    Sometimes applications may use the `write()` callable returned
+    by the `start_response` function.  This tries to resolve such edge
+    cases automatically.  But if you don't get the expected output you
+    should set `buffered` to `True` which enforces buffering.
+
+    If passed an invalid WSGI application the behavior of this function is
+    undefined.  Never pass non-conforming WSGI applications to this function.
+
+    :param app: the application to execute.
+    :param buffered: set to `True` to enforce buffering.
+    :return: tuple in the form ``(app_iter, status, headers)``
+    """
+    environ = _get_environ(environ)
+    response = []
+    buffer = []
+
+    def start_response(status, headers, exc_info=None):
+        if exc_info is not None:
+            reraise(*exc_info)
+        response[:] = [status, headers]
+        return buffer.append
+
+    app_rv = app(environ, start_response)
+    close_func = getattr(app_rv, "close", None)
+    app_iter = iter(app_rv)
+
+    # when buffering we emit the close call early and convert the
+    # application iterator into a regular list
+    if buffered:
+        try:
+            app_iter = list(app_iter)
+        finally:
+            if close_func is not None:
+                close_func()
+
+    # otherwise we iterate the application iter until we have a response, chain
+    # the already received data with the already collected data and wrap it in
+    # a new `ClosingIterator` if we need to restore a `close` callable from the
+    # original return value.
+    else:
+        for item in app_iter:
+            buffer.append(item)
+            if response:
+                break
+        if buffer:
+            app_iter = chain(buffer, app_iter)
+        if close_func is not None and app_iter is not app_rv:
+            app_iter = ClosingIterator(app_iter, close_func)
+
+    return app_iter, response[0], Headers(response[1])
diff --git a/python/werkzeug/testapp.py b/python/werkzeug/testapp.py
new file mode 100644
index 0000000..8ea23be
--- /dev/null
+++ b/python/werkzeug/testapp.py
@@ -0,0 +1,241 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.testapp
+    ~~~~~~~~~~~~~~~~
+
+    Provide a small test application that can be used to test a WSGI server
+    and check it for WSGI compliance.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import base64
+import os
+import sys
+from textwrap import wrap
+
+import werkzeug
+from .utils import escape
+from .wrappers import BaseRequest as Request
+from .wrappers import BaseResponse as Response
+
+logo = Response(
+    base64.b64decode(
+        """
+R0lGODlhoACgAOMIAAEDACwpAEpCAGdgAJaKAM28AOnVAP3rAP/////////
+//////////////////////yH5BAEKAAgALAAAAACgAKAAAAT+EMlJq704680R+F0ojmRpnuj0rWnrv
+nB8rbRs33gu0bzu/0AObxgsGn3D5HHJbCUFyqZ0ukkSDlAidctNFg7gbI9LZlrBaHGtzAae0eloe25
+7w9EDOX2fst/xenyCIn5/gFqDiVVDV4aGeYiKkhSFjnCQY5OTlZaXgZp8nJ2ekaB0SQOjqphrpnOiq
+ncEn65UsLGytLVmQ6m4sQazpbtLqL/HwpnER8bHyLrLOc3Oz8PRONPU1crXN9na263dMt/g4SzjMeX
+m5yDpLqgG7OzJ4u8lT/P69ej3JPn69kHzN2OIAHkB9RUYSFCFQYQJFTIkCDBiwoXWGnowaLEjRm7+G
+p9A7Hhx4rUkAUaSLJlxHMqVMD/aSycSZkyTplCqtGnRAM5NQ1Ly5OmzZc6gO4d6DGAUKA+hSocWYAo
+SlM6oUWX2O/o0KdaVU5vuSQLAa0ADwQgMEMB2AIECZhVSnTno6spgbtXmHcBUrQACcc2FrTrWS8wAf
+78cMFBgwIBgbN+qvTt3ayikRBk7BoyGAGABAdYyfdzRQGV3l4coxrqQ84GpUBmrdR3xNIDUPAKDBSA
+ADIGDhhqTZIWaDcrVX8EsbNzbkvCOxG8bN5w8ly9H8jyTJHC6DFndQydbguh2e/ctZJFXRxMAqqPVA
+tQH5E64SPr1f0zz7sQYjAHg0In+JQ11+N2B0XXBeeYZgBZFx4tqBToiTCPv0YBgQv8JqA6BEf6RhXx
+w1ENhRBnWV8ctEX4Ul2zc3aVGcQNC2KElyTDYyYUWvShdjDyMOGMuFjqnII45aogPhz/CodUHFwaDx
+lTgsaOjNyhGWJQd+lFoAGk8ObghI0kawg+EV5blH3dr+digkYuAGSaQZFHFz2P/cTaLmhF52QeSb45
+Jwxd+uSVGHlqOZpOeJpCFZ5J+rkAkFjQ0N1tah7JJSZUFNsrkeJUJMIBi8jyaEKIhKPomnC91Uo+NB
+yyaJ5umnnpInIFh4t6ZSpGaAVmizqjpByDegYl8tPE0phCYrhcMWSv+uAqHfgH88ak5UXZmlKLVJhd
+dj78s1Fxnzo6yUCrV6rrDOkluG+QzCAUTbCwf9SrmMLzK6p+OPHx7DF+bsfMRq7Ec61Av9i6GLw23r
+idnZ+/OO0a99pbIrJkproCQMA17OPG6suq3cca5ruDfXCCDoS7BEdvmJn5otdqscn+uogRHHXs8cbh
+EIfYaDY1AkrC0cqwcZpnM6ludx72x0p7Fo/hZAcpJDjax0UdHavMKAbiKltMWCF3xxh9k25N/Viud8
+ba78iCvUkt+V6BpwMlErmcgc502x+u1nSxJSJP9Mi52awD1V4yB/QHONsnU3L+A/zR4VL/indx/y64
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+JyTyDoAJfPdu8v7DRZAxsP/ky9MJ3OL36DJfCFPASC3/aXlfLOOON9vGZZHydGf8LnxYJuuVIbl83y
+Az5n/RPz07E+9+zw2A2ahz4HxHo9Kt79HTMx1Q7ma7zAzHgHqYH0SoZWyTuOLMiHwSfZDAQTn0ajk9
+YQqodnUYjByQZhZak9Wu4gYQsMyEpIOAOQKze8CmEF45KuAHTvIDOfHJNipwoHMuGHBnJElUoDmAyX
+c2Qm/R8Ah/iILCCJOEokGowdhDYc/yoL+vpRGwyVSCWFYZNljkhEirGXsalWcAgOdeAdoXcktF2udb
+qbUhjWyMQxYO01o6KYKOr6iK3fE4MaS+DsvBsGOBaMb0Y6IxADaJhFICaOLmiWTlDAnY1KzDG4ambL
+cWBA8mUzjJsN2KjSaSXGqMCVXYpYkj33mcIApyhQf6YqgeNAmNvuC0t4CsDbSshZJkCS1eNisKqlyG
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+KiDlFdt6jnCSqx7Dmt6XnqSKaFFHNO5+FmODxMCWBEaco77lNDGXBM0ECYB/+s7nKFdwSF5hgXumQe
+EZ7amRg39RHy3zIjyRCykQh8Zo2iviRKyTDn/zx6EefptJj2Cw+Ep2FSc01U5ry4KLPYsTyWnVGnvb
+UpyGlhjBUljyjHhWpf8OFaXwhp9O4T1gU9UeyPPa8A2l0p1kNqPXEVRm1AOs1oAGZU596t6SOR2mcB
+Oco1srWtkaVrMUzIErrKri85keKqRQYX9VX0/eAUK1hrSu6HMEX3Qh2sCh0q0D2CtnUqS4hj62sE/z
+aDs2Sg7MBS6xnQeooc2R2tC9YrKpEi9pLXfYXp20tDCpSP8rKlrD4axprb9u1Df5hSbz9QU0cRpfgn
+kiIzwKucd0wsEHlLpe5yHXuc6FrNelOl7pY2+11kTWx7VpRu97dXA3DO1vbkhcb4zyvERYajQgAADs
+="""
+    ),
+    mimetype="image/png",
+)
+
+
+TEMPLATE = u"""\
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
+  "http://www.w3.org/TR/html4/loose.dtd">
+<title>WSGI Information</title>
+<style type="text/css">
+  @import url(https://fonts.googleapis.com/css?family=Ubuntu);
+
+  body       { font-family: 'Lucida Grande', 'Lucida Sans Unicode', 'Geneva',
+               'Verdana', sans-serif; background-color: white; color: #000;
+               font-size: 15px; text-align: center; }
+  #logo      { float: right; padding: 0 0 10px 10px; }
+  div.box    { text-align: left; width: 45em; margin: auto; padding: 50px 0;
+               background-color: white; }
+  h1, h2     { font-family: 'Ubuntu', 'Lucida Grande', 'Lucida Sans Unicode',
+               'Geneva', 'Verdana', sans-serif; font-weight: normal; }
+  h1         { margin: 0 0 30px 0; }
+  h2         { font-size: 1.4em; margin: 1em 0 0.5em 0; }
+  table      { width: 100%%; border-collapse: collapse; border: 1px solid #AFC5C9 }
+  table th   { background-color: #AFC1C4; color: white; font-size: 0.72em;
+               font-weight: normal; width: 18em; vertical-align: top;
+               padding: 0.5em 0 0.1em 0.5em; }
+  table td   { border: 1px solid #AFC5C9; padding: 0.1em 0 0.1em 0.5em; }
+  code       { font-family: 'Consolas', 'Monaco', 'Bitstream Vera Sans Mono',
+               monospace; font-size: 0.7em; }
+  ul li      { line-height: 1.5em; }
+  ul.path    { font-size: 0.7em; margin: 0 -30px; padding: 8px 30px;
+               list-style: none; background: #E8EFF0; }
+  ul.path li { line-height: 1.6em; }
+  li.virtual { color: #999; text-decoration: underline; }
+  li.exp     { background: white; }
+</style>
+<div class="box">
+  <img src="?resource=logo" id="logo" alt="[The Werkzeug Logo]" />
+  <h1>WSGI Information</h1>
+  <p>
+    This page displays all available information about the WSGI server and
+    the underlying Python interpreter.
+  <h2 id="python-interpreter">Python Interpreter</h2>
+  <table>
+    <tr>
+      <th>Python Version
+      <td>%(python_version)s
+    <tr>
+      <th>Platform
+      <td>%(platform)s [%(os)s]
+    <tr>
+      <th>API Version
+      <td>%(api_version)s
+    <tr>
+      <th>Byteorder
+      <td>%(byteorder)s
+    <tr>
+      <th>Werkzeug Version
+      <td>%(werkzeug_version)s
+  </table>
+  <h2 id="wsgi-environment">WSGI Environment</h2>
+  <table>%(wsgi_env)s</table>
+  <h2 id="installed-eggs">Installed Eggs</h2>
+  <p>
+    The following python packages were installed on the system as
+    Python eggs:
+  <ul>%(python_eggs)s</ul>
+  <h2 id="sys-path">System Path</h2>
+  <p>
+    The following paths are the current contents of the load path.  The
+    following entries are looked up for Python packages.  Note that not
+    all items in this path are folders.  Gray and underlined items are
+    entries pointing to invalid resources or used by custom import hooks
+    such as the zip importer.
+  <p>
+    Items with a bright background were expanded for display from a relative
+    path.  If you encounter such paths in the output you might want to check
+    your setup as relative paths are usually problematic in multithreaded
+    environments.
+  <ul class="path">%(sys_path)s</ul>
+</div>
+"""
+
+
+def iter_sys_path():
+    if os.name == "posix":
+
+        def strip(x):
+            prefix = os.path.expanduser("~")
+            if x.startswith(prefix):
+                x = "~" + x[len(prefix) :]
+            return x
+
+    else:
+
+        def strip(x):
+            return x
+
+    cwd = os.path.abspath(os.getcwd())
+    for item in sys.path:
+        path = os.path.join(cwd, item or os.path.curdir)
+        yield strip(os.path.normpath(path)), not os.path.isdir(path), path != item
+
+
+def render_testapp(req):
+    try:
+        import pkg_resources
+    except ImportError:
+        eggs = ()
+    else:
+        eggs = sorted(pkg_resources.working_set, key=lambda x: x.project_name.lower())
+    python_eggs = []
+    for egg in eggs:
+        try:
+            version = egg.version
+        except (ValueError, AttributeError):
+            version = "unknown"
+        python_eggs.append(
+            "<li>%s <small>[%s]</small>" % (escape(egg.project_name), escape(version))
+        )
+
+    wsgi_env = []
+    sorted_environ = sorted(req.environ.items(), key=lambda x: repr(x[0]).lower())
+    for key, value in sorted_environ:
+        wsgi_env.append(
+            "<tr><th>%s<td><code>%s</code>"
+            % (escape(str(key)), " ".join(wrap(escape(repr(value)))))
+        )
+
+    sys_path = []
+    for item, virtual, expanded in iter_sys_path():
+        class_ = []
+        if virtual:
+            class_.append("virtual")
+        if expanded:
+            class_.append("exp")
+        sys_path.append(
+            "<li%s>%s"
+            % (' class="%s"' % " ".join(class_) if class_ else "", escape(item))
+        )
+
+    return (
+        TEMPLATE
+        % {
+            "python_version": "<br>".join(escape(sys.version).splitlines()),
+            "platform": escape(sys.platform),
+            "os": escape(os.name),
+            "api_version": sys.api_version,
+            "byteorder": sys.byteorder,
+            "werkzeug_version": werkzeug.__version__,
+            "python_eggs": "\n".join(python_eggs),
+            "wsgi_env": "\n".join(wsgi_env),
+            "sys_path": "\n".join(sys_path),
+        }
+    ).encode("utf-8")
+
+
+def test_app(environ, start_response):
+    """Simple test application that dumps the environment.  You can use
+    it to check if Werkzeug is working properly:
+
+    .. sourcecode:: pycon
+
+        >>> from werkzeug.serving import run_simple
+        >>> from werkzeug.testapp import test_app
+        >>> run_simple('localhost', 3000, test_app)
+         * Running on http://localhost:3000/
+
+    The application displays important information from the WSGI environment,
+    the Python interpreter and the installed libraries.
+    """
+    req = Request(environ, populate_request=False)
+    if req.args.get("resource") == "logo":
+        response = logo
+    else:
+        response = Response(render_testapp(req), mimetype="text/html")
+    return response(environ, start_response)
+
+
+if __name__ == "__main__":
+    from .serving import run_simple
+
+    run_simple("localhost", 5000, test_app, use_reloader=True)
diff --git a/python/werkzeug/urls.py b/python/werkzeug/urls.py
new file mode 100644
index 0000000..38e9e5a
--- /dev/null
+++ b/python/werkzeug/urls.py
@@ -0,0 +1,1134 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.urls
+    ~~~~~~~~~~~~~
+
+    ``werkzeug.urls`` used to provide several wrapper functions for Python 2
+    urlparse, whose main purpose were to work around the behavior of the Py2
+    stdlib and its lack of unicode support. While this was already a somewhat
+    inconvenient situation, it got even more complicated because Python 3's
+    ``urllib.parse`` actually does handle unicode properly. In other words,
+    this module would wrap two libraries with completely different behavior. So
+    now this module contains a 2-and-3-compatible backport of Python 3's
+    ``urllib.parse``, which is mostly API-compatible.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import codecs
+import os
+import re
+from collections import namedtuple
+
+from ._compat import fix_tuple_repr
+from ._compat import implements_to_string
+from ._compat import make_literal_wrapper
+from ._compat import normalize_string_tuple
+from ._compat import PY2
+from ._compat import text_type
+from ._compat import to_native
+from ._compat import to_unicode
+from ._compat import try_coerce_native
+from ._internal import _decode_idna
+from ._internal import _encode_idna
+from .datastructures import iter_multi_items
+from .datastructures import MultiDict
+
+# A regular expression for what a valid schema looks like
+_scheme_re = re.compile(r"^[a-zA-Z0-9+-.]+$")
+
+# Characters that are safe in any part of an URL.
+_always_safe = frozenset(
+    bytearray(
+        b"abcdefghijklmnopqrstuvwxyz"
+        b"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+        b"0123456789"
+        b"-._~"
+    )
+)
+
+_hexdigits = "0123456789ABCDEFabcdef"
+_hextobyte = dict(
+    ((a + b).encode(), int(a + b, 16)) for a in _hexdigits for b in _hexdigits
+)
+_bytetohex = [("%%%02X" % char).encode("ascii") for char in range(256)]
+
+
+_URLTuple = fix_tuple_repr(
+    namedtuple("_URLTuple", ["scheme", "netloc", "path", "query", "fragment"])
+)
+
+
+class BaseURL(_URLTuple):
+    """Superclass of :py:class:`URL` and :py:class:`BytesURL`."""
+
+    __slots__ = ()
+
+    def replace(self, **kwargs):
+        """Return an URL with the same values, except for those parameters
+        given new values by whichever keyword arguments are specified."""
+        return self._replace(**kwargs)
+
+    @property
+    def host(self):
+        """The host part of the URL if available, otherwise `None`.  The
+        host is either the hostname or the IP address mentioned in the
+        URL.  It will not contain the port.
+        """
+        return self._split_host()[0]
+
+    @property
+    def ascii_host(self):
+        """Works exactly like :attr:`host` but will return a result that
+        is restricted to ASCII.  If it finds a netloc that is not ASCII
+        it will attempt to idna decode it.  This is useful for socket
+        operations when the URL might include internationalized characters.
+        """
+        rv = self.host
+        if rv is not None and isinstance(rv, text_type):
+            try:
+                rv = _encode_idna(rv)
+            except UnicodeError:
+                rv = rv.encode("ascii", "ignore")
+        return to_native(rv, "ascii", "ignore")
+
+    @property
+    def port(self):
+        """The port in the URL as an integer if it was present, `None`
+        otherwise.  This does not fill in default ports.
+        """
+        try:
+            rv = int(to_native(self._split_host()[1]))
+            if 0 <= rv <= 65535:
+                return rv
+        except (ValueError, TypeError):
+            pass
+
+    @property
+    def auth(self):
+        """The authentication part in the URL if available, `None`
+        otherwise.
+        """
+        return self._split_netloc()[0]
+
+    @property
+    def username(self):
+        """The username if it was part of the URL, `None` otherwise.
+        This undergoes URL decoding and will always be a unicode string.
+        """
+        rv = self._split_auth()[0]
+        if rv is not None:
+            return _url_unquote_legacy(rv)
+
+    @property
+    def raw_username(self):
+        """The username if it was part of the URL, `None` otherwise.
+        Unlike :attr:`username` this one is not being decoded.
+        """
+        return self._split_auth()[0]
+
+    @property
+    def password(self):
+        """The password if it was part of the URL, `None` otherwise.
+        This undergoes URL decoding and will always be a unicode string.
+        """
+        rv = self._split_auth()[1]
+        if rv is not None:
+            return _url_unquote_legacy(rv)
+
+    @property
+    def raw_password(self):
+        """The password if it was part of the URL, `None` otherwise.
+        Unlike :attr:`password` this one is not being decoded.
+        """
+        return self._split_auth()[1]
+
+    def decode_query(self, *args, **kwargs):
+        """Decodes the query part of the URL.  Ths is a shortcut for
+        calling :func:`url_decode` on the query argument.  The arguments and
+        keyword arguments are forwarded to :func:`url_decode` unchanged.
+        """
+        return url_decode(self.query, *args, **kwargs)
+
+    def join(self, *args, **kwargs):
+        """Joins this URL with another one.  This is just a convenience
+        function for calling into :meth:`url_join` and then parsing the
+        return value again.
+        """
+        return url_parse(url_join(self, *args, **kwargs))
+
+    def to_url(self):
+        """Returns a URL string or bytes depending on the type of the
+        information stored.  This is just a convenience function
+        for calling :meth:`url_unparse` for this URL.
+        """
+        return url_unparse(self)
+
+    def decode_netloc(self):
+        """Decodes the netloc part into a string."""
+        rv = _decode_idna(self.host or "")
+
+        if ":" in rv:
+            rv = "[%s]" % rv
+        port = self.port
+        if port is not None:
+            rv = "%s:%d" % (rv, port)
+        auth = ":".join(
+            filter(
+                None,
+                [
+                    _url_unquote_legacy(self.raw_username or "", "/:%@"),
+                    _url_unquote_legacy(self.raw_password or "", "/:%@"),
+                ],
+            )
+        )
+        if auth:
+            rv = "%s@%s" % (auth, rv)
+        return rv
+
+    def to_uri_tuple(self):
+        """Returns a :class:`BytesURL` tuple that holds a URI.  This will
+        encode all the information in the URL properly to ASCII using the
+        rules a web browser would follow.
+
+        It's usually more interesting to directly call :meth:`iri_to_uri` which
+        will return a string.
+        """
+        return url_parse(iri_to_uri(self).encode("ascii"))
+
+    def to_iri_tuple(self):
+        """Returns a :class:`URL` tuple that holds a IRI.  This will try
+        to decode as much information as possible in the URL without
+        losing information similar to how a web browser does it for the
+        URL bar.
+
+        It's usually more interesting to directly call :meth:`uri_to_iri` which
+        will return a string.
+        """
+        return url_parse(uri_to_iri(self))
+
+    def get_file_location(self, pathformat=None):
+        """Returns a tuple with the location of the file in the form
+        ``(server, location)``.  If the netloc is empty in the URL or
+        points to localhost, it's represented as ``None``.
+
+        The `pathformat` by default is autodetection but needs to be set
+        when working with URLs of a specific system.  The supported values
+        are ``'windows'`` when working with Windows or DOS paths and
+        ``'posix'`` when working with posix paths.
+
+        If the URL does not point to a local file, the server and location
+        are both represented as ``None``.
+
+        :param pathformat: The expected format of the path component.
+                           Currently ``'windows'`` and ``'posix'`` are
+                           supported.  Defaults to ``None`` which is
+                           autodetect.
+        """
+        if self.scheme != "file":
+            return None, None
+
+        path = url_unquote(self.path)
+        host = self.netloc or None
+
+        if pathformat is None:
+            if os.name == "nt":
+                pathformat = "windows"
+            else:
+                pathformat = "posix"
+
+        if pathformat == "windows":
+            if path[:1] == "/" and path[1:2].isalpha() and path[2:3] in "|:":
+                path = path[1:2] + ":" + path[3:]
+            windows_share = path[:3] in ("\\" * 3, "/" * 3)
+            import ntpath
+
+            path = ntpath.normpath(path)
+            # Windows shared drives are represented as ``\\host\\directory``.
+            # That results in a URL like ``file://///host/directory``, and a
+            # path like ``///host/directory``. We need to special-case this
+            # because the path contains the hostname.
+            if windows_share and host is None:
+                parts = path.lstrip("\\").split("\\", 1)
+                if len(parts) == 2:
+                    host, path = parts
+                else:
+                    host = parts[0]
+                    path = ""
+        elif pathformat == "posix":
+            import posixpath
+
+            path = posixpath.normpath(path)
+        else:
+            raise TypeError("Invalid path format %s" % repr(pathformat))
+
+        if host in ("127.0.0.1", "::1", "localhost"):
+            host = None
+
+        return host, path
+
+    def _split_netloc(self):
+        if self._at in self.netloc:
+            return self.netloc.split(self._at, 1)
+        return None, self.netloc
+
+    def _split_auth(self):
+        auth = self._split_netloc()[0]
+        if not auth:
+            return None, None
+        if self._colon not in auth:
+            return auth, None
+        return auth.split(self._colon, 1)
+
+    def _split_host(self):
+        rv = self._split_netloc()[1]
+        if not rv:
+            return None, None
+
+        if not rv.startswith(self._lbracket):
+            if self._colon in rv:
+                return rv.split(self._colon, 1)
+            return rv, None
+
+        idx = rv.find(self._rbracket)
+        if idx < 0:
+            return rv, None
+
+        host = rv[1:idx]
+        rest = rv[idx + 1 :]
+        if rest.startswith(self._colon):
+            return host, rest[1:]
+        return host, None
+
+
+@implements_to_string
+class URL(BaseURL):
+    """Represents a parsed URL.  This behaves like a regular tuple but
+    also has some extra attributes that give further insight into the
+    URL.
+    """
+
+    __slots__ = ()
+    _at = "@"
+    _colon = ":"
+    _lbracket = "["
+    _rbracket = "]"
+
+    def __str__(self):
+        return self.to_url()
+
+    def encode_netloc(self):
+        """Encodes the netloc part to an ASCII safe URL as bytes."""
+        rv = self.ascii_host or ""
+        if ":" in rv:
+            rv = "[%s]" % rv
+        port = self.port
+        if port is not None:
+            rv = "%s:%d" % (rv, port)
+        auth = ":".join(
+            filter(
+                None,
+                [
+                    url_quote(self.raw_username or "", "utf-8", "strict", "/:%"),
+                    url_quote(self.raw_password or "", "utf-8", "strict", "/:%"),
+                ],
+            )
+        )
+        if auth:
+            rv = "%s@%s" % (auth, rv)
+        return to_native(rv)
+
+    def encode(self, charset="utf-8", errors="replace"):
+        """Encodes the URL to a tuple made out of bytes.  The charset is
+        only being used for the path, query and fragment.
+        """
+        return BytesURL(
+            self.scheme.encode("ascii"),
+            self.encode_netloc(),
+            self.path.encode(charset, errors),
+            self.query.encode(charset, errors),
+            self.fragment.encode(charset, errors),
+        )
+
+
+class BytesURL(BaseURL):
+    """Represents a parsed URL in bytes."""
+
+    __slots__ = ()
+    _at = b"@"
+    _colon = b":"
+    _lbracket = b"["
+    _rbracket = b"]"
+
+    def __str__(self):
+        return self.to_url().decode("utf-8", "replace")
+
+    def encode_netloc(self):
+        """Returns the netloc unchanged as bytes."""
+        return self.netloc
+
+    def decode(self, charset="utf-8", errors="replace"):
+        """Decodes the URL to a tuple made out of strings.  The charset is
+        only being used for the path, query and fragment.
+        """
+        return URL(
+            self.scheme.decode("ascii"),
+            self.decode_netloc(),
+            self.path.decode(charset, errors),
+            self.query.decode(charset, errors),
+            self.fragment.decode(charset, errors),
+        )
+
+
+_unquote_maps = {frozenset(): _hextobyte}
+
+
+def _unquote_to_bytes(string, unsafe=""):
+    if isinstance(string, text_type):
+        string = string.encode("utf-8")
+
+    if isinstance(unsafe, text_type):
+        unsafe = unsafe.encode("utf-8")
+
+    unsafe = frozenset(bytearray(unsafe))
+    groups = iter(string.split(b"%"))
+    result = bytearray(next(groups, b""))
+
+    try:
+        hex_to_byte = _unquote_maps[unsafe]
+    except KeyError:
+        hex_to_byte = _unquote_maps[unsafe] = {
+            h: b for h, b in _hextobyte.items() if b not in unsafe
+        }
+
+    for group in groups:
+        code = group[:2]
+
+        if code in hex_to_byte:
+            result.append(hex_to_byte[code])
+            result.extend(group[2:])
+        else:
+            result.append(37)  # %
+            result.extend(group)
+
+    return bytes(result)
+
+
+def _url_encode_impl(obj, charset, encode_keys, sort, key):
+    iterable = iter_multi_items(obj)
+    if sort:
+        iterable = sorted(iterable, key=key)
+    for key, value in iterable:
+        if value is None:
+            continue
+        if not isinstance(key, bytes):
+            key = text_type(key).encode(charset)
+        if not isinstance(value, bytes):
+            value = text_type(value).encode(charset)
+        yield _fast_url_quote_plus(key) + "=" + _fast_url_quote_plus(value)
+
+
+def _url_unquote_legacy(value, unsafe=""):
+    try:
+        return url_unquote(value, charset="utf-8", errors="strict", unsafe=unsafe)
+    except UnicodeError:
+        return url_unquote(value, charset="latin1", unsafe=unsafe)
+
+
+def url_parse(url, scheme=None, allow_fragments=True):
+    """Parses a URL from a string into a :class:`URL` tuple.  If the URL
+    is lacking a scheme it can be provided as second argument. Otherwise,
+    it is ignored.  Optionally fragments can be stripped from the URL
+    by setting `allow_fragments` to `False`.
+
+    The inverse of this function is :func:`url_unparse`.
+
+    :param url: the URL to parse.
+    :param scheme: the default schema to use if the URL is schemaless.
+    :param allow_fragments: if set to `False` a fragment will be removed
+                            from the URL.
+    """
+    s = make_literal_wrapper(url)
+    is_text_based = isinstance(url, text_type)
+
+    if scheme is None:
+        scheme = s("")
+    netloc = query = fragment = s("")
+    i = url.find(s(":"))
+    if i > 0 and _scheme_re.match(to_native(url[:i], errors="replace")):
+        # make sure "iri" is not actually a port number (in which case
+        # "scheme" is really part of the path)
+        rest = url[i + 1 :]
+        if not rest or any(c not in s("0123456789") for c in rest):
+            # not a port number
+            scheme, url = url[:i].lower(), rest
+
+    if url[:2] == s("//"):
+        delim = len(url)
+        for c in s("/?#"):
+            wdelim = url.find(c, 2)
+            if wdelim >= 0:
+                delim = min(delim, wdelim)
+        netloc, url = url[2:delim], url[delim:]
+        if (s("[") in netloc and s("]") not in netloc) or (
+            s("]") in netloc and s("[") not in netloc
+        ):
+            raise ValueError("Invalid IPv6 URL")
+
+    if allow_fragments and s("#") in url:
+        url, fragment = url.split(s("#"), 1)
+    if s("?") in url:
+        url, query = url.split(s("?"), 1)
+
+    result_type = URL if is_text_based else BytesURL
+    return result_type(scheme, netloc, url, query, fragment)
+
+
+def _make_fast_url_quote(charset="utf-8", errors="strict", safe="/:", unsafe=""):
+    """Precompile the translation table for a URL encoding function.
+
+    Unlike :func:`url_quote`, the generated function only takes the
+    string to quote.
+
+    :param charset: The charset to encode the result with.
+    :param errors: How to handle encoding errors.
+    :param safe: An optional sequence of safe characters to never encode.
+    :param unsafe: An optional sequence of unsafe characters to always encode.
+    """
+    if isinstance(safe, text_type):
+        safe = safe.encode(charset, errors)
+
+    if isinstance(unsafe, text_type):
+        unsafe = unsafe.encode(charset, errors)
+
+    safe = (frozenset(bytearray(safe)) | _always_safe) - frozenset(bytearray(unsafe))
+    table = [chr(c) if c in safe else "%%%02X" % c for c in range(256)]
+
+    if not PY2:
+
+        def quote(string):
+            return "".join([table[c] for c in string])
+
+    else:
+
+        def quote(string):
+            return "".join([table[c] for c in bytearray(string)])
+
+    return quote
+
+
+_fast_url_quote = _make_fast_url_quote()
+_fast_quote_plus = _make_fast_url_quote(safe=" ", unsafe="+")
+
+
+def _fast_url_quote_plus(string):
+    return _fast_quote_plus(string).replace(" ", "+")
+
+
+def url_quote(string, charset="utf-8", errors="strict", safe="/:", unsafe=""):
+    """URL encode a single string with a given encoding.
+
+    :param s: the string to quote.
+    :param charset: the charset to be used.
+    :param safe: an optional sequence of safe characters.
+    :param unsafe: an optional sequence of unsafe characters.
+
+    .. versionadded:: 0.9.2
+       The `unsafe` parameter was added.
+    """
+    if not isinstance(string, (text_type, bytes, bytearray)):
+        string = text_type(string)
+    if isinstance(string, text_type):
+        string = string.encode(charset, errors)
+    if isinstance(safe, text_type):
+        safe = safe.encode(charset, errors)
+    if isinstance(unsafe, text_type):
+        unsafe = unsafe.encode(charset, errors)
+    safe = (frozenset(bytearray(safe)) | _always_safe) - frozenset(bytearray(unsafe))
+    rv = bytearray()
+    for char in bytearray(string):
+        if char in safe:
+            rv.append(char)
+        else:
+            rv.extend(_bytetohex[char])
+    return to_native(bytes(rv))
+
+
+def url_quote_plus(string, charset="utf-8", errors="strict", safe=""):
+    """URL encode a single string with the given encoding and convert
+    whitespace to "+".
+
+    :param s: The string to quote.
+    :param charset: The charset to be used.
+    :param safe: An optional sequence of safe characters.
+    """
+    return url_quote(string, charset, errors, safe + " ", "+").replace(" ", "+")
+
+
+def url_unparse(components):
+    """The reverse operation to :meth:`url_parse`.  This accepts arbitrary
+    as well as :class:`URL` tuples and returns a URL as a string.
+
+    :param components: the parsed URL as tuple which should be converted
+                       into a URL string.
+    """
+    scheme, netloc, path, query, fragment = normalize_string_tuple(components)
+    s = make_literal_wrapper(scheme)
+    url = s("")
+
+    # We generally treat file:///x and file:/x the same which is also
+    # what browsers seem to do.  This also allows us to ignore a schema
+    # register for netloc utilization or having to differenciate between
+    # empty and missing netloc.
+    if netloc or (scheme and path.startswith(s("/"))):
+        if path and path[:1] != s("/"):
+            path = s("/") + path
+        url = s("//") + (netloc or s("")) + path
+    elif path:
+        url += path
+    if scheme:
+        url = scheme + s(":") + url
+    if query:
+        url = url + s("?") + query
+    if fragment:
+        url = url + s("#") + fragment
+    return url
+
+
+def url_unquote(string, charset="utf-8", errors="replace", unsafe=""):
+    """URL decode a single string with a given encoding.  If the charset
+    is set to `None` no unicode decoding is performed and raw bytes
+    are returned.
+
+    :param s: the string to unquote.
+    :param charset: the charset of the query string.  If set to `None`
+                    no unicode decoding will take place.
+    :param errors: the error handling for the charset decoding.
+    """
+    rv = _unquote_to_bytes(string, unsafe)
+    if charset is not None:
+        rv = rv.decode(charset, errors)
+    return rv
+
+
+def url_unquote_plus(s, charset="utf-8", errors="replace"):
+    """URL decode a single string with the given `charset` and decode "+" to
+    whitespace.
+
+    Per default encoding errors are ignored.  If you want a different behavior
+    you can set `errors` to ``'replace'`` or ``'strict'``.  In strict mode a
+    :exc:`HTTPUnicodeError` is raised.
+
+    :param s: The string to unquote.
+    :param charset: the charset of the query string.  If set to `None`
+                    no unicode decoding will take place.
+    :param errors: The error handling for the `charset` decoding.
+    """
+    if isinstance(s, text_type):
+        s = s.replace(u"+", u" ")
+    else:
+        s = s.replace(b"+", b" ")
+    return url_unquote(s, charset, errors)
+
+
+def url_fix(s, charset="utf-8"):
+    r"""Sometimes you get an URL by a user that just isn't a real URL because
+    it contains unsafe characters like ' ' and so on. This function can fix
+    some of the problems in a similar way browsers handle data entered by the
+    user:
+
+    >>> url_fix(u'http://de.wikipedia.org/wiki/Elf (Begriffskl\xe4rung)')
+    'http://de.wikipedia.org/wiki/Elf%20(Begriffskl%C3%A4rung)'
+
+    :param s: the string with the URL to fix.
+    :param charset: The target charset for the URL if the url was given as
+                    unicode string.
+    """
+    # First step is to switch to unicode processing and to convert
+    # backslashes (which are invalid in URLs anyways) to slashes.  This is
+    # consistent with what Chrome does.
+    s = to_unicode(s, charset, "replace").replace("\\", "/")
+
+    # For the specific case that we look like a malformed windows URL
+    # we want to fix this up manually:
+    if s.startswith("file://") and s[7:8].isalpha() and s[8:10] in (":/", "|/"):
+        s = "file:///" + s[7:]
+
+    url = url_parse(s)
+    path = url_quote(url.path, charset, safe="/%+$!*'(),")
+    qs = url_quote_plus(url.query, charset, safe=":&%=+$!*'(),")
+    anchor = url_quote_plus(url.fragment, charset, safe=":&%=+$!*'(),")
+    return to_native(url_unparse((url.scheme, url.encode_netloc(), path, qs, anchor)))
+
+
+# not-unreserved characters remain quoted when unquoting to IRI
+_to_iri_unsafe = "".join([chr(c) for c in range(128) if c not in _always_safe])
+
+
+def _codec_error_url_quote(e):
+    """Used in :func:`uri_to_iri` after unquoting to re-quote any
+    invalid bytes.
+    """
+    out = _fast_url_quote(e.object[e.start : e.end])
+
+    if PY2:
+        out = out.decode("utf-8")
+
+    return out, e.end
+
+
+codecs.register_error("werkzeug.url_quote", _codec_error_url_quote)
+
+
+def uri_to_iri(uri, charset="utf-8", errors="werkzeug.url_quote"):
+    """Convert a URI to an IRI. All valid UTF-8 characters are unquoted,
+    leaving all reserved and invalid characters quoted. If the URL has
+    a domain, it is decoded from Punycode.
+
+    >>> uri_to_iri("http://xn--n3h.net/p%C3%A5th?q=%C3%A8ry%DF")
+    'http://\\u2603.net/p\\xe5th?q=\\xe8ry%DF'
+
+    :param uri: The URI to convert.
+    :param charset: The encoding to encode unquoted bytes with.
+    :param errors: Error handler to use during ``bytes.encode``. By
+        default, invalid bytes are left quoted.
+
+    .. versionchanged:: 0.15
+        All reserved and invalid characters remain quoted. Previously,
+        only some reserved characters were preserved, and invalid bytes
+        were replaced instead of left quoted.
+
+    .. versionadded:: 0.6
+    """
+    if isinstance(uri, tuple):
+        uri = url_unparse(uri)
+
+    uri = url_parse(to_unicode(uri, charset))
+    path = url_unquote(uri.path, charset, errors, _to_iri_unsafe)
+    query = url_unquote(uri.query, charset, errors, _to_iri_unsafe)
+    fragment = url_unquote(uri.fragment, charset, errors, _to_iri_unsafe)
+    return url_unparse((uri.scheme, uri.decode_netloc(), path, query, fragment))
+
+
+# reserved characters remain unquoted when quoting to URI
+_to_uri_safe = ":/?#[]@!$&'()*+,;=%"
+
+
+def iri_to_uri(iri, charset="utf-8", errors="strict", safe_conversion=False):
+    """Convert an IRI to a URI. All non-ASCII and unsafe characters are
+    quoted. If the URL has a domain, it is encoded to Punycode.
+
+    >>> iri_to_uri('http://\\u2603.net/p\\xe5th?q=\\xe8ry%DF')
+    'http://xn--n3h.net/p%C3%A5th?q=%C3%A8ry%DF'
+
+    :param iri: The IRI to convert.
+    :param charset: The encoding of the IRI.
+    :param errors: Error handler to use during ``bytes.encode``.
+    :param safe_conversion: Return the URL unchanged if it only contains
+        ASCII characters and no whitespace. See the explanation below.
+
+    There is a general problem with IRI conversion with some protocols
+    that are in violation of the URI specification. Consider the
+    following two IRIs::
+
+        magnet:?xt=uri:whatever
+        itms-services://?action=download-manifest
+
+    After parsing, we don't know if the scheme requires the ``//``,
+    which is dropped if empty, but conveys different meanings in the
+    final URL if it's present or not. In this case, you can use
+    ``safe_conversion``, which will return the URL unchanged if it only
+    contains ASCII characters and no whitespace. This can result in a
+    URI with unquoted characters if it was not already quoted correctly,
+    but preserves the URL's semantics. Werkzeug uses this for the
+    ``Location`` header for redirects.
+
+    .. versionchanged:: 0.15
+        All reserved characters remain unquoted. Previously, only some
+        reserved characters were left unquoted.
+
+    .. versionchanged:: 0.9.6
+       The ``safe_conversion`` parameter was added.
+
+    .. versionadded:: 0.6
+    """
+    if isinstance(iri, tuple):
+        iri = url_unparse(iri)
+
+    if safe_conversion:
+        # If we're not sure if it's safe to convert the URL, and it only
+        # contains ASCII characters, return it unconverted.
+        try:
+            native_iri = to_native(iri)
+            ascii_iri = native_iri.encode("ascii")
+
+            # Only return if it doesn't have whitespace. (Why?)
+            if len(ascii_iri.split()) == 1:
+                return native_iri
+        except UnicodeError:
+            pass
+
+    iri = url_parse(to_unicode(iri, charset, errors))
+    path = url_quote(iri.path, charset, errors, _to_uri_safe)
+    query = url_quote(iri.query, charset, errors, _to_uri_safe)
+    fragment = url_quote(iri.fragment, charset, errors, _to_uri_safe)
+    return to_native(
+        url_unparse((iri.scheme, iri.encode_netloc(), path, query, fragment))
+    )
+
+
+def url_decode(
+    s,
+    charset="utf-8",
+    decode_keys=False,
+    include_empty=True,
+    errors="replace",
+    separator="&",
+    cls=None,
+):
+    """
+    Parse a querystring and return it as :class:`MultiDict`.  There is a
+    difference in key decoding on different Python versions.  On Python 3
+    keys will always be fully decoded whereas on Python 2, keys will
+    remain bytestrings if they fit into ASCII.  On 2.x keys can be forced
+    to be unicode by setting `decode_keys` to `True`.
+
+    If the charset is set to `None` no unicode decoding will happen and
+    raw bytes will be returned.
+
+    Per default a missing value for a key will default to an empty key.  If
+    you don't want that behavior you can set `include_empty` to `False`.
+
+    Per default encoding errors are ignored.  If you want a different behavior
+    you can set `errors` to ``'replace'`` or ``'strict'``.  In strict mode a
+    `HTTPUnicodeError` is raised.
+
+    .. versionchanged:: 0.5
+       In previous versions ";" and "&" could be used for url decoding.
+       This changed in 0.5 where only "&" is supported.  If you want to
+       use ";" instead a different `separator` can be provided.
+
+       The `cls` parameter was added.
+
+    :param s: a string with the query string to decode.
+    :param charset: the charset of the query string.  If set to `None`
+                    no unicode decoding will take place.
+    :param decode_keys: Used on Python 2.x to control whether keys should
+                        be forced to be unicode objects.  If set to `True`
+                        then keys will be unicode in all cases. Otherwise,
+                        they remain `str` if they fit into ASCII.
+    :param include_empty: Set to `False` if you don't want empty values to
+                          appear in the dict.
+    :param errors: the decoding error behavior.
+    :param separator: the pair separator to be used, defaults to ``&``
+    :param cls: an optional dict class to use.  If this is not specified
+                       or `None` the default :class:`MultiDict` is used.
+    """
+    if cls is None:
+        cls = MultiDict
+    if isinstance(s, text_type) and not isinstance(separator, text_type):
+        separator = separator.decode(charset or "ascii")
+    elif isinstance(s, bytes) and not isinstance(separator, bytes):
+        separator = separator.encode(charset or "ascii")
+    return cls(
+        _url_decode_impl(
+            s.split(separator), charset, decode_keys, include_empty, errors
+        )
+    )
+
+
+def url_decode_stream(
+    stream,
+    charset="utf-8",
+    decode_keys=False,
+    include_empty=True,
+    errors="replace",
+    separator="&",
+    cls=None,
+    limit=None,
+    return_iterator=False,
+):
+    """Works like :func:`url_decode` but decodes a stream.  The behavior
+    of stream and limit follows functions like
+    :func:`~werkzeug.wsgi.make_line_iter`.  The generator of pairs is
+    directly fed to the `cls` so you can consume the data while it's
+    parsed.
+
+    .. versionadded:: 0.8
+
+    :param stream: a stream with the encoded querystring
+    :param charset: the charset of the query string.  If set to `None`
+                    no unicode decoding will take place.
+    :param decode_keys: Used on Python 2.x to control whether keys should
+                        be forced to be unicode objects.  If set to `True`,
+                        keys will be unicode in all cases. Otherwise, they
+                        remain `str` if they fit into ASCII.
+    :param include_empty: Set to `False` if you don't want empty values to
+                          appear in the dict.
+    :param errors: the decoding error behavior.
+    :param separator: the pair separator to be used, defaults to ``&``
+    :param cls: an optional dict class to use.  If this is not specified
+                       or `None` the default :class:`MultiDict` is used.
+    :param limit: the content length of the URL data.  Not necessary if
+                  a limited stream is provided.
+    :param return_iterator: if set to `True` the `cls` argument is ignored
+                            and an iterator over all decoded pairs is
+                            returned
+    """
+    from .wsgi import make_chunk_iter
+
+    pair_iter = make_chunk_iter(stream, separator, limit)
+    decoder = _url_decode_impl(pair_iter, charset, decode_keys, include_empty, errors)
+
+    if return_iterator:
+        return decoder
+
+    if cls is None:
+        cls = MultiDict
+
+    return cls(decoder)
+
+
+def _url_decode_impl(pair_iter, charset, decode_keys, include_empty, errors):
+    for pair in pair_iter:
+        if not pair:
+            continue
+        s = make_literal_wrapper(pair)
+        equal = s("=")
+        if equal in pair:
+            key, value = pair.split(equal, 1)
+        else:
+            if not include_empty:
+                continue
+            key = pair
+            value = s("")
+        key = url_unquote_plus(key, charset, errors)
+        if charset is not None and PY2 and not decode_keys:
+            key = try_coerce_native(key)
+        yield key, url_unquote_plus(value, charset, errors)
+
+
+def url_encode(
+    obj, charset="utf-8", encode_keys=False, sort=False, key=None, separator=b"&"
+):
+    """URL encode a dict/`MultiDict`.  If a value is `None` it will not appear
+    in the result string.  Per default only values are encoded into the target
+    charset strings.  If `encode_keys` is set to ``True`` unicode keys are
+    supported too.
+
+    If `sort` is set to `True` the items are sorted by `key` or the default
+    sorting algorithm.
+
+    .. versionadded:: 0.5
+        `sort`, `key`, and `separator` were added.
+
+    :param obj: the object to encode into a query string.
+    :param charset: the charset of the query string.
+    :param encode_keys: set to `True` if you have unicode keys. (Ignored on
+                        Python 3.x)
+    :param sort: set to `True` if you want parameters to be sorted by `key`.
+    :param separator: the separator to be used for the pairs.
+    :param key: an optional function to be used for sorting.  For more details
+                check out the :func:`sorted` documentation.
+    """
+    separator = to_native(separator, "ascii")
+    return separator.join(_url_encode_impl(obj, charset, encode_keys, sort, key))
+
+
+def url_encode_stream(
+    obj,
+    stream=None,
+    charset="utf-8",
+    encode_keys=False,
+    sort=False,
+    key=None,
+    separator=b"&",
+):
+    """Like :meth:`url_encode` but writes the results to a stream
+    object.  If the stream is `None` a generator over all encoded
+    pairs is returned.
+
+    .. versionadded:: 0.8
+
+    :param obj: the object to encode into a query string.
+    :param stream: a stream to write the encoded object into or `None` if
+                   an iterator over the encoded pairs should be returned.  In
+                   that case the separator argument is ignored.
+    :param charset: the charset of the query string.
+    :param encode_keys: set to `True` if you have unicode keys. (Ignored on
+                        Python 3.x)
+    :param sort: set to `True` if you want parameters to be sorted by `key`.
+    :param separator: the separator to be used for the pairs.
+    :param key: an optional function to be used for sorting.  For more details
+                check out the :func:`sorted` documentation.
+    """
+    separator = to_native(separator, "ascii")
+    gen = _url_encode_impl(obj, charset, encode_keys, sort, key)
+    if stream is None:
+        return gen
+    for idx, chunk in enumerate(gen):
+        if idx:
+            stream.write(separator)
+        stream.write(chunk)
+
+
+def url_join(base, url, allow_fragments=True):
+    """Join a base URL and a possibly relative URL to form an absolute
+    interpretation of the latter.
+
+    :param base: the base URL for the join operation.
+    :param url: the URL to join.
+    :param allow_fragments: indicates whether fragments should be allowed.
+    """
+    if isinstance(base, tuple):
+        base = url_unparse(base)
+    if isinstance(url, tuple):
+        url = url_unparse(url)
+
+    base, url = normalize_string_tuple((base, url))
+    s = make_literal_wrapper(base)
+
+    if not base:
+        return url
+    if not url:
+        return base
+
+    bscheme, bnetloc, bpath, bquery, bfragment = url_parse(
+        base, allow_fragments=allow_fragments
+    )
+    scheme, netloc, path, query, fragment = url_parse(url, bscheme, allow_fragments)
+    if scheme != bscheme:
+        return url
+    if netloc:
+        return url_unparse((scheme, netloc, path, query, fragment))
+    netloc = bnetloc
+
+    if path[:1] == s("/"):
+        segments = path.split(s("/"))
+    elif not path:
+        segments = bpath.split(s("/"))
+        if not query:
+            query = bquery
+    else:
+        segments = bpath.split(s("/"))[:-1] + path.split(s("/"))
+
+    # If the rightmost part is "./" we want to keep the slash but
+    # remove the dot.
+    if segments[-1] == s("."):
+        segments[-1] = s("")
+
+    # Resolve ".." and "."
+    segments = [segment for segment in segments if segment != s(".")]
+    while 1:
+        i = 1
+        n = len(segments) - 1
+        while i < n:
+            if segments[i] == s("..") and segments[i - 1] not in (s(""), s("..")):
+                del segments[i - 1 : i + 1]
+                break
+            i += 1
+        else:
+            break
+
+    # Remove trailing ".." if the URL is absolute
+    unwanted_marker = [s(""), s("..")]
+    while segments[:2] == unwanted_marker:
+        del segments[1]
+
+    path = s("/").join(segments)
+    return url_unparse((scheme, netloc, path, query, fragment))
+
+
+class Href(object):
+    """Implements a callable that constructs URLs with the given base. The
+    function can be called with any number of positional and keyword
+    arguments which than are used to assemble the URL.  Works with URLs
+    and posix paths.
+
+    Positional arguments are appended as individual segments to
+    the path of the URL:
+
+    >>> href = Href('/foo')
+    >>> href('bar', 23)
+    '/foo/bar/23'
+    >>> href('foo', bar=23)
+    '/foo/foo?bar=23'
+
+    If any of the arguments (positional or keyword) evaluates to `None` it
+    will be skipped.  If no keyword arguments are given the last argument
+    can be a :class:`dict` or :class:`MultiDict` (or any other dict subclass),
+    otherwise the keyword arguments are used for the query parameters, cutting
+    off the first trailing underscore of the parameter name:
+
+    >>> href(is_=42)
+    '/foo?is=42'
+    >>> href({'foo': 'bar'})
+    '/foo?foo=bar'
+
+    Combining of both methods is not allowed:
+
+    >>> href({'foo': 'bar'}, bar=42)
+    Traceback (most recent call last):
+      ...
+    TypeError: keyword arguments and query-dicts can't be combined
+
+    Accessing attributes on the href object creates a new href object with
+    the attribute name as prefix:
+
+    >>> bar_href = href.bar
+    >>> bar_href("blub")
+    '/foo/bar/blub'
+
+    If `sort` is set to `True` the items are sorted by `key` or the default
+    sorting algorithm:
+
+    >>> href = Href("/", sort=True)
+    >>> href(a=1, b=2, c=3)
+    '/?a=1&b=2&c=3'
+
+    .. versionadded:: 0.5
+        `sort` and `key` were added.
+    """
+
+    def __init__(self, base="./", charset="utf-8", sort=False, key=None):
+        if not base:
+            base = "./"
+        self.base = base
+        self.charset = charset
+        self.sort = sort
+        self.key = key
+
+    def __getattr__(self, name):
+        if name[:2] == "__":
+            raise AttributeError(name)
+        base = self.base
+        if base[-1:] != "/":
+            base += "/"
+        return Href(url_join(base, name), self.charset, self.sort, self.key)
+
+    def __call__(self, *path, **query):
+        if path and isinstance(path[-1], dict):
+            if query:
+                raise TypeError("keyword arguments and query-dicts can't be combined")
+            query, path = path[-1], path[:-1]
+        elif query:
+            query = dict(
+                [(k.endswith("_") and k[:-1] or k, v) for k, v in query.items()]
+            )
+        path = "/".join(
+            [
+                to_unicode(url_quote(x, self.charset), "ascii")
+                for x in path
+                if x is not None
+            ]
+        ).lstrip("/")
+        rv = self.base
+        if path:
+            if not rv.endswith("/"):
+                rv += "/"
+            rv = url_join(rv, "./" + path)
+        if query:
+            rv += "?" + to_unicode(
+                url_encode(query, self.charset, sort=self.sort, key=self.key), "ascii"
+            )
+        return to_native(rv)
diff --git a/python/werkzeug/useragents.py b/python/werkzeug/useragents.py
new file mode 100644
index 0000000..e265e09
--- /dev/null
+++ b/python/werkzeug/useragents.py
@@ -0,0 +1,220 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.useragents
+    ~~~~~~~~~~~~~~~~~~~
+
+    This module provides a helper to inspect user agent strings.  This module
+    is far from complete but should work for most of the currently available
+    browsers.
+
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import re
+import warnings
+
+
+class UserAgentParser(object):
+    """A simple user agent parser.  Used by the `UserAgent`."""
+
+    platforms = (
+        ("cros", "chromeos"),
+        ("iphone|ios", "iphone"),
+        ("ipad", "ipad"),
+        (r"darwin|mac|os\s*x", "macos"),
+        ("win", "windows"),
+        (r"android", "android"),
+        ("netbsd", "netbsd"),
+        ("openbsd", "openbsd"),
+        ("freebsd", "freebsd"),
+        ("dragonfly", "dragonflybsd"),
+        ("(sun|i86)os", "solaris"),
+        (r"x11|lin(\b|ux)?", "linux"),
+        (r"nintendo\s+wii", "wii"),
+        ("irix", "irix"),
+        ("hp-?ux", "hpux"),
+        ("aix", "aix"),
+        ("sco|unix_sv", "sco"),
+        ("bsd", "bsd"),
+        ("amiga", "amiga"),
+        ("blackberry|playbook", "blackberry"),
+        ("symbian", "symbian"),
+    )
+    browsers = (
+        ("googlebot", "google"),
+        ("msnbot", "msn"),
+        ("yahoo", "yahoo"),
+        ("ask jeeves", "ask"),
+        (r"aol|america\s+online\s+browser", "aol"),
+        ("opera", "opera"),
+        ("edge", "edge"),
+        ("chrome|crios", "chrome"),
+        ("seamonkey", "seamonkey"),
+        ("firefox|firebird|phoenix|iceweasel", "firefox"),
+        ("galeon", "galeon"),
+        ("safari|version", "safari"),
+        ("webkit", "webkit"),
+        ("camino", "camino"),
+        ("konqueror", "konqueror"),
+        ("k-meleon", "kmeleon"),
+        ("netscape", "netscape"),
+        (r"msie|microsoft\s+internet\s+explorer|trident/.+? rv:", "msie"),
+        ("lynx", "lynx"),
+        ("links", "links"),
+        ("Baiduspider", "baidu"),
+        ("bingbot", "bing"),
+        ("mozilla", "mozilla"),
+    )
+
+    _browser_version_re = r"(?:%s)[/\sa-z(]*(\d+[.\da-z]+)?"
+    _language_re = re.compile(
+        r"(?:;\s*|\s+)(\b\w{2}\b(?:-\b\w{2}\b)?)\s*;|"
+        r"(?:\(|\[|;)\s*(\b\w{2}\b(?:-\b\w{2}\b)?)\s*(?:\]|\)|;)"
+    )
+
+    def __init__(self):
+        self.platforms = [(b, re.compile(a, re.I)) for a, b in self.platforms]
+        self.browsers = [
+            (b, re.compile(self._browser_version_re % a, re.I))
+            for a, b in self.browsers
+        ]
+
+    def __call__(self, user_agent):
+        for platform, regex in self.platforms:  # noqa: B007
+            match = regex.search(user_agent)
+            if match is not None:
+                break
+        else:
+            platform = None
+        for browser, regex in self.browsers:  # noqa: B007
+            match = regex.search(user_agent)
+            if match is not None:
+                version = match.group(1)
+                break
+        else:
+            browser = version = None
+        match = self._language_re.search(user_agent)
+        if match is not None:
+            language = match.group(1) or match.group(2)
+        else:
+            language = None
+        return platform, browser, version, language
+
+
+class UserAgent(object):
+    """Represents a user agent.  Pass it a WSGI environment or a user agent
+    string and you can inspect some of the details from the user agent
+    string via the attributes.  The following attributes exist:
+
+    .. attribute:: string
+
+       the raw user agent string
+
+    .. attribute:: platform
+
+       the browser platform.  The following platforms are currently
+       recognized:
+
+       -   `aix`
+       -   `amiga`
+       -   `android`
+       -   `blackberry`
+       -   `bsd`
+       -   `chromeos`
+       -   `dragonflybsd`
+       -   `freebsd`
+       -   `hpux`
+       -   `ipad`
+       -   `iphone`
+       -   `irix`
+       -   `linux`
+       -   `macos`
+       -   `netbsd`
+       -   `openbsd`
+       -   `sco`
+       -   `solaris`
+       -   `symbian`
+       -   `wii`
+       -   `windows`
+
+    .. attribute:: browser
+
+        the name of the browser.  The following browsers are currently
+        recognized:
+
+        -   `aol` *
+        -   `ask` *
+        -   `baidu` *
+        -   `bing` *
+        -   `camino`
+        -   `chrome`
+        -   `edge`
+        -   `firefox`
+        -   `galeon`
+        -   `google` *
+        -   `kmeleon`
+        -   `konqueror`
+        -   `links`
+        -   `lynx`
+        -   `mozilla`
+        -   `msie`
+        -   `msn`
+        -   `netscape`
+        -   `opera`
+        -   `safari`
+        -   `seamonkey`
+        -   `webkit`
+        -   `yahoo` *
+
+        (Browsers marked with a star (``*``) are crawlers.)
+
+    .. attribute:: version
+
+        the version of the browser
+
+    .. attribute:: language
+
+        the language of the browser
+    """
+
+    _parser = UserAgentParser()
+
+    def __init__(self, environ_or_string):
+        if isinstance(environ_or_string, dict):
+            environ_or_string = environ_or_string.get("HTTP_USER_AGENT", "")
+        self.string = environ_or_string
+        self.platform, self.browser, self.version, self.language = self._parser(
+            environ_or_string
+        )
+
+    def to_header(self):
+        return self.string
+
+    def __str__(self):
+        return self.string
+
+    def __nonzero__(self):
+        return bool(self.browser)
+
+    __bool__ = __nonzero__
+
+    def __repr__(self):
+        return "<%s %r/%s>" % (self.__class__.__name__, self.browser, self.version)
+
+
+# DEPRECATED
+from .wrappers import UserAgentMixin as _UserAgentMixin
+
+
+class UserAgentMixin(_UserAgentMixin):
+    @property
+    def user_agent(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.useragents.UserAgentMixin' should be imported"
+            " from 'werkzeug.wrappers.UserAgentMixin'. This old import"
+            " will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return super(_UserAgentMixin, self).user_agent
diff --git a/python/werkzeug/utils.py b/python/werkzeug/utils.py
new file mode 100644
index 0000000..2062057
--- /dev/null
+++ b/python/werkzeug/utils.py
@@ -0,0 +1,836 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.utils
+    ~~~~~~~~~~~~~~
+
+    This module implements various utilities for WSGI applications.  Most of
+    them are used by the request and response wrappers but especially for
+    middleware development it makes sense to use them without the wrappers.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import codecs
+import os
+import pkgutil
+import re
+import sys
+import warnings
+
+from ._compat import iteritems
+from ._compat import PY2
+from ._compat import reraise
+from ._compat import string_types
+from ._compat import text_type
+from ._compat import unichr
+from ._internal import _DictAccessorProperty
+from ._internal import _missing
+from ._internal import _parse_signature
+
+try:
+    from html.entities import name2codepoint
+except ImportError:
+    from htmlentitydefs import name2codepoint
+
+
+_format_re = re.compile(r"\$(?:(%s)|\{(%s)\})" % (("[a-zA-Z_][a-zA-Z0-9_]*",) * 2))
+_entity_re = re.compile(r"&([^;]+);")
+_filename_ascii_strip_re = re.compile(r"[^A-Za-z0-9_.-]")
+_windows_device_files = (
+    "CON",
+    "AUX",
+    "COM1",
+    "COM2",
+    "COM3",
+    "COM4",
+    "LPT1",
+    "LPT2",
+    "LPT3",
+    "PRN",
+    "NUL",
+)
+
+
+class cached_property(property):
+    """A decorator that converts a function into a lazy property.  The
+    function wrapped is called the first time to retrieve the result
+    and then that calculated result is used the next time you access
+    the value::
+
+        class Foo(object):
+
+            @cached_property
+            def foo(self):
+                # calculate something important here
+                return 42
+
+    The class has to have a `__dict__` in order for this property to
+    work.
+    """
+
+    # implementation detail: A subclass of python's builtin property
+    # decorator, we override __get__ to check for a cached value. If one
+    # chooses to invoke __get__ by hand the property will still work as
+    # expected because the lookup logic is replicated in __get__ for
+    # manual invocation.
+
+    def __init__(self, func, name=None, doc=None):
+        self.__name__ = name or func.__name__
+        self.__module__ = func.__module__
+        self.__doc__ = doc or func.__doc__
+        self.func = func
+
+    def __set__(self, obj, value):
+        obj.__dict__[self.__name__] = value
+
+    def __get__(self, obj, type=None):
+        if obj is None:
+            return self
+        value = obj.__dict__.get(self.__name__, _missing)
+        if value is _missing:
+            value = self.func(obj)
+            obj.__dict__[self.__name__] = value
+        return value
+
+
+class environ_property(_DictAccessorProperty):
+    """Maps request attributes to environment variables. This works not only
+    for the Werzeug request object, but also any other class with an
+    environ attribute:
+
+    >>> class Test(object):
+    ...     environ = {'key': 'value'}
+    ...     test = environ_property('key')
+    >>> var = Test()
+    >>> var.test
+    'value'
+
+    If you pass it a second value it's used as default if the key does not
+    exist, the third one can be a converter that takes a value and converts
+    it.  If it raises :exc:`ValueError` or :exc:`TypeError` the default value
+    is used. If no default value is provided `None` is used.
+
+    Per default the property is read only.  You have to explicitly enable it
+    by passing ``read_only=False`` to the constructor.
+    """
+
+    read_only = True
+
+    def lookup(self, obj):
+        return obj.environ
+
+
+class header_property(_DictAccessorProperty):
+    """Like `environ_property` but for headers."""
+
+    def lookup(self, obj):
+        return obj.headers
+
+
+class HTMLBuilder(object):
+    """Helper object for HTML generation.
+
+    Per default there are two instances of that class.  The `html` one, and
+    the `xhtml` one for those two dialects.  The class uses keyword parameters
+    and positional parameters to generate small snippets of HTML.
+
+    Keyword parameters are converted to XML/SGML attributes, positional
+    arguments are used as children.  Because Python accepts positional
+    arguments before keyword arguments it's a good idea to use a list with the
+    star-syntax for some children:
+
+    >>> html.p(class_='foo', *[html.a('foo', href='foo.html'), ' ',
+    ...                        html.a('bar', href='bar.html')])
+    u'<p class="foo"><a href="foo.html">foo</a> <a href="bar.html">bar</a></p>'
+
+    This class works around some browser limitations and can not be used for
+    arbitrary SGML/XML generation.  For that purpose lxml and similar
+    libraries exist.
+
+    Calling the builder escapes the string passed:
+
+    >>> html.p(html("<foo>"))
+    u'<p>&lt;foo&gt;</p>'
+    """
+
+    _entity_re = re.compile(r"&([^;]+);")
+    _entities = name2codepoint.copy()
+    _entities["apos"] = 39
+    _empty_elements = {
+        "area",
+        "base",
+        "basefont",
+        "br",
+        "col",
+        "command",
+        "embed",
+        "frame",
+        "hr",
+        "img",
+        "input",
+        "keygen",
+        "isindex",
+        "link",
+        "meta",
+        "param",
+        "source",
+        "wbr",
+    }
+    _boolean_attributes = {
+        "selected",
+        "checked",
+        "compact",
+        "declare",
+        "defer",
+        "disabled",
+        "ismap",
+        "multiple",
+        "nohref",
+        "noresize",
+        "noshade",
+        "nowrap",
+    }
+    _plaintext_elements = {"textarea"}
+    _c_like_cdata = {"script", "style"}
+
+    def __init__(self, dialect):
+        self._dialect = dialect
+
+    def __call__(self, s):
+        return escape(s)
+
+    def __getattr__(self, tag):
+        if tag[:2] == "__":
+            raise AttributeError(tag)
+
+        def proxy(*children, **arguments):
+            buffer = "<" + tag
+            for key, value in iteritems(arguments):
+                if value is None:
+                    continue
+                if key[-1] == "_":
+                    key = key[:-1]
+                if key in self._boolean_attributes:
+                    if not value:
+                        continue
+                    if self._dialect == "xhtml":
+                        value = '="' + key + '"'
+                    else:
+                        value = ""
+                else:
+                    value = '="' + escape(value) + '"'
+                buffer += " " + key + value
+            if not children and tag in self._empty_elements:
+                if self._dialect == "xhtml":
+                    buffer += " />"
+                else:
+                    buffer += ">"
+                return buffer
+            buffer += ">"
+
+            children_as_string = "".join(
+                [text_type(x) for x in children if x is not None]
+            )
+
+            if children_as_string:
+                if tag in self._plaintext_elements:
+                    children_as_string = escape(children_as_string)
+                elif tag in self._c_like_cdata and self._dialect == "xhtml":
+                    children_as_string = (
+                        "/*<![CDATA[*/" + children_as_string + "/*]]>*/"
+                    )
+            buffer += children_as_string + "</" + tag + ">"
+            return buffer
+
+        return proxy
+
+    def __repr__(self):
+        return "<%s for %r>" % (self.__class__.__name__, self._dialect)
+
+
+html = HTMLBuilder("html")
+xhtml = HTMLBuilder("xhtml")
+
+# https://cgit.freedesktop.org/xdg/shared-mime-info/tree/freedesktop.org.xml.in
+# https://www.iana.org/assignments/media-types/media-types.xhtml
+# Types listed in the XDG mime info that have a charset in the IANA registration.
+_charset_mimetypes = {
+    "application/ecmascript",
+    "application/javascript",
+    "application/sql",
+    "application/xml",
+    "application/xml-dtd",
+    "application/xml-external-parsed-entity",
+}
+
+
+def get_content_type(mimetype, charset):
+    """Returns the full content type string with charset for a mimetype.
+
+    If the mimetype represents text, the charset parameter will be
+    appended, otherwise the mimetype is returned unchanged.
+
+    :param mimetype: The mimetype to be used as content type.
+    :param charset: The charset to be appended for text mimetypes.
+    :return: The content type.
+
+    .. verionchanged:: 0.15
+        Any type that ends with ``+xml`` gets a charset, not just those
+        that start with ``application/``. Known text types such as
+        ``application/javascript`` are also given charsets.
+    """
+    if (
+        mimetype.startswith("text/")
+        or mimetype in _charset_mimetypes
+        or mimetype.endswith("+xml")
+    ):
+        mimetype += "; charset=" + charset
+
+    return mimetype
+
+
+def detect_utf_encoding(data):
+    """Detect which UTF encoding was used to encode the given bytes.
+
+    The latest JSON standard (:rfc:`8259`) suggests that only UTF-8 is
+    accepted. Older documents allowed 8, 16, or 32. 16 and 32 can be big
+    or little endian. Some editors or libraries may prepend a BOM.
+
+    :internal:
+
+    :param data: Bytes in unknown UTF encoding.
+    :return: UTF encoding name
+
+    .. versionadded:: 0.15
+    """
+    head = data[:4]
+
+    if head[:3] == codecs.BOM_UTF8:
+        return "utf-8-sig"
+
+    if b"\x00" not in head:
+        return "utf-8"
+
+    if head in (codecs.BOM_UTF32_BE, codecs.BOM_UTF32_LE):
+        return "utf-32"
+
+    if head[:2] in (codecs.BOM_UTF16_BE, codecs.BOM_UTF16_LE):
+        return "utf-16"
+
+    if len(head) == 4:
+        if head[:3] == b"\x00\x00\x00":
+            return "utf-32-be"
+
+        if head[::2] == b"\x00\x00":
+            return "utf-16-be"
+
+        if head[1:] == b"\x00\x00\x00":
+            return "utf-32-le"
+
+        if head[1::2] == b"\x00\x00":
+            return "utf-16-le"
+
+    if len(head) == 2:
+        return "utf-16-be" if head.startswith(b"\x00") else "utf-16-le"
+
+    return "utf-8"
+
+
+def format_string(string, context):
+    """String-template format a string:
+
+    >>> format_string('$foo and ${foo}s', dict(foo=42))
+    '42 and 42s'
+
+    This does not do any attribute lookup etc.  For more advanced string
+    formattings have a look at the `werkzeug.template` module.
+
+    :param string: the format string.
+    :param context: a dict with the variables to insert.
+    """
+
+    def lookup_arg(match):
+        x = context[match.group(1) or match.group(2)]
+        if not isinstance(x, string_types):
+            x = type(string)(x)
+        return x
+
+    return _format_re.sub(lookup_arg, string)
+
+
+def secure_filename(filename):
+    r"""Pass it a filename and it will return a secure version of it.  This
+    filename can then safely be stored on a regular file system and passed
+    to :func:`os.path.join`.  The filename returned is an ASCII only string
+    for maximum portability.
+
+    On windows systems the function also makes sure that the file is not
+    named after one of the special device files.
+
+    >>> secure_filename("My cool movie.mov")
+    'My_cool_movie.mov'
+    >>> secure_filename("../../../etc/passwd")
+    'etc_passwd'
+    >>> secure_filename(u'i contain cool \xfcml\xe4uts.txt')
+    'i_contain_cool_umlauts.txt'
+
+    The function might return an empty filename.  It's your responsibility
+    to ensure that the filename is unique and that you abort or
+    generate a random filename if the function returned an empty one.
+
+    .. versionadded:: 0.5
+
+    :param filename: the filename to secure
+    """
+    if isinstance(filename, text_type):
+        from unicodedata import normalize
+
+        filename = normalize("NFKD", filename).encode("ascii", "ignore")
+        if not PY2:
+            filename = filename.decode("ascii")
+    for sep in os.path.sep, os.path.altsep:
+        if sep:
+            filename = filename.replace(sep, " ")
+    filename = str(_filename_ascii_strip_re.sub("", "_".join(filename.split()))).strip(
+        "._"
+    )
+
+    # on nt a couple of special files are present in each folder.  We
+    # have to ensure that the target file is not such a filename.  In
+    # this case we prepend an underline
+    if (
+        os.name == "nt"
+        and filename
+        and filename.split(".")[0].upper() in _windows_device_files
+    ):
+        filename = "_" + filename
+
+    return filename
+
+
+def escape(s, quote=None):
+    """Replace special characters "&", "<", ">" and (") to HTML-safe sequences.
+
+    There is a special handling for `None` which escapes to an empty string.
+
+    .. versionchanged:: 0.9
+       `quote` is now implicitly on.
+
+    :param s: the string to escape.
+    :param quote: ignored.
+    """
+    if s is None:
+        return ""
+    elif hasattr(s, "__html__"):
+        return text_type(s.__html__())
+    elif not isinstance(s, string_types):
+        s = text_type(s)
+    if quote is not None:
+        from warnings import warn
+
+        warn(
+            "The 'quote' parameter is no longer used as of version 0.9"
+            " and will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+    s = (
+        s.replace("&", "&amp;")
+        .replace("<", "&lt;")
+        .replace(">", "&gt;")
+        .replace('"', "&quot;")
+    )
+    return s
+
+
+def unescape(s):
+    """The reverse function of `escape`.  This unescapes all the HTML
+    entities, not only the XML entities inserted by `escape`.
+
+    :param s: the string to unescape.
+    """
+
+    def handle_match(m):
+        name = m.group(1)
+        if name in HTMLBuilder._entities:
+            return unichr(HTMLBuilder._entities[name])
+        try:
+            if name[:2] in ("#x", "#X"):
+                return unichr(int(name[2:], 16))
+            elif name.startswith("#"):
+                return unichr(int(name[1:]))
+        except ValueError:
+            pass
+        return u""
+
+    return _entity_re.sub(handle_match, s)
+
+
+def redirect(location, code=302, Response=None):
+    """Returns a response object (a WSGI application) that, if called,
+    redirects the client to the target location. Supported codes are
+    301, 302, 303, 305, 307, and 308. 300 is not supported because
+    it's not a real redirect and 304 because it's the answer for a
+    request with a request with defined If-Modified-Since headers.
+
+    .. versionadded:: 0.6
+       The location can now be a unicode string that is encoded using
+       the :func:`iri_to_uri` function.
+
+    .. versionadded:: 0.10
+        The class used for the Response object can now be passed in.
+
+    :param location: the location the response should redirect to.
+    :param code: the redirect status code. defaults to 302.
+    :param class Response: a Response class to use when instantiating a
+        response. The default is :class:`werkzeug.wrappers.Response` if
+        unspecified.
+    """
+    if Response is None:
+        from .wrappers import Response
+
+    display_location = escape(location)
+    if isinstance(location, text_type):
+        # Safe conversion is necessary here as we might redirect
+        # to a broken URI scheme (for instance itms-services).
+        from .urls import iri_to_uri
+
+        location = iri_to_uri(location, safe_conversion=True)
+    response = Response(
+        '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">\n'
+        "<title>Redirecting...</title>\n"
+        "<h1>Redirecting...</h1>\n"
+        "<p>You should be redirected automatically to target URL: "
+        '<a href="%s">%s</a>.  If not click the link.'
+        % (escape(location), display_location),
+        code,
+        mimetype="text/html",
+    )
+    response.headers["Location"] = location
+    return response
+
+
+def append_slash_redirect(environ, code=301):
+    """Redirects to the same URL but with a slash appended.  The behavior
+    of this function is undefined if the path ends with a slash already.
+
+    :param environ: the WSGI environment for the request that triggers
+                    the redirect.
+    :param code: the status code for the redirect.
+    """
+    new_path = environ["PATH_INFO"].strip("/") + "/"
+    query_string = environ.get("QUERY_STRING")
+    if query_string:
+        new_path += "?" + query_string
+    return redirect(new_path, code)
+
+
+def import_string(import_name, silent=False):
+    """Imports an object based on a string.  This is useful if you want to
+    use import paths as endpoints or something similar.  An import path can
+    be specified either in dotted notation (``xml.sax.saxutils.escape``)
+    or with a colon as object delimiter (``xml.sax.saxutils:escape``).
+
+    If `silent` is True the return value will be `None` if the import fails.
+
+    :param import_name: the dotted name for the object to import.
+    :param silent: if set to `True` import errors are ignored and
+                   `None` is returned instead.
+    :return: imported object
+    """
+    # force the import name to automatically convert to strings
+    # __import__ is not able to handle unicode strings in the fromlist
+    # if the module is a package
+    import_name = str(import_name).replace(":", ".")
+    try:
+        try:
+            __import__(import_name)
+        except ImportError:
+            if "." not in import_name:
+                raise
+        else:
+            return sys.modules[import_name]
+
+        module_name, obj_name = import_name.rsplit(".", 1)
+        module = __import__(module_name, globals(), locals(), [obj_name])
+        try:
+            return getattr(module, obj_name)
+        except AttributeError as e:
+            raise ImportError(e)
+
+    except ImportError as e:
+        if not silent:
+            reraise(
+                ImportStringError, ImportStringError(import_name, e), sys.exc_info()[2]
+            )
+
+
+def find_modules(import_path, include_packages=False, recursive=False):
+    """Finds all the modules below a package.  This can be useful to
+    automatically import all views / controllers so that their metaclasses /
+    function decorators have a chance to register themselves on the
+    application.
+
+    Packages are not returned unless `include_packages` is `True`.  This can
+    also recursively list modules but in that case it will import all the
+    packages to get the correct load path of that module.
+
+    :param import_path: the dotted name for the package to find child modules.
+    :param include_packages: set to `True` if packages should be returned, too.
+    :param recursive: set to `True` if recursion should happen.
+    :return: generator
+    """
+    module = import_string(import_path)
+    path = getattr(module, "__path__", None)
+    if path is None:
+        raise ValueError("%r is not a package" % import_path)
+    basename = module.__name__ + "."
+    for _importer, modname, ispkg in pkgutil.iter_modules(path):
+        modname = basename + modname
+        if ispkg:
+            if include_packages:
+                yield modname
+            if recursive:
+                for item in find_modules(modname, include_packages, True):
+                    yield item
+        else:
+            yield modname
+
+
+def validate_arguments(func, args, kwargs, drop_extra=True):
+    """Checks if the function accepts the arguments and keyword arguments.
+    Returns a new ``(args, kwargs)`` tuple that can safely be passed to
+    the function without causing a `TypeError` because the function signature
+    is incompatible.  If `drop_extra` is set to `True` (which is the default)
+    any extra positional or keyword arguments are dropped automatically.
+
+    The exception raised provides three attributes:
+
+    `missing`
+        A set of argument names that the function expected but where
+        missing.
+
+    `extra`
+        A dict of keyword arguments that the function can not handle but
+        where provided.
+
+    `extra_positional`
+        A list of values that where given by positional argument but the
+        function cannot accept.
+
+    This can be useful for decorators that forward user submitted data to
+    a view function::
+
+        from werkzeug.utils import ArgumentValidationError, validate_arguments
+
+        def sanitize(f):
+            def proxy(request):
+                data = request.values.to_dict()
+                try:
+                    args, kwargs = validate_arguments(f, (request,), data)
+                except ArgumentValidationError:
+                    raise BadRequest('The browser failed to transmit all '
+                                     'the data expected.')
+                return f(*args, **kwargs)
+            return proxy
+
+    :param func: the function the validation is performed against.
+    :param args: a tuple of positional arguments.
+    :param kwargs: a dict of keyword arguments.
+    :param drop_extra: set to `False` if you don't want extra arguments
+                       to be silently dropped.
+    :return: tuple in the form ``(args, kwargs)``.
+    """
+    parser = _parse_signature(func)
+    args, kwargs, missing, extra, extra_positional = parser(args, kwargs)[:5]
+    if missing:
+        raise ArgumentValidationError(tuple(missing))
+    elif (extra or extra_positional) and not drop_extra:
+        raise ArgumentValidationError(None, extra, extra_positional)
+    return tuple(args), kwargs
+
+
+def bind_arguments(func, args, kwargs):
+    """Bind the arguments provided into a dict.  When passed a function,
+    a tuple of arguments and a dict of keyword arguments `bind_arguments`
+    returns a dict of names as the function would see it.  This can be useful
+    to implement a cache decorator that uses the function arguments to build
+    the cache key based on the values of the arguments.
+
+    :param func: the function the arguments should be bound for.
+    :param args: tuple of positional arguments.
+    :param kwargs: a dict of keyword arguments.
+    :return: a :class:`dict` of bound keyword arguments.
+    """
+    (
+        args,
+        kwargs,
+        missing,
+        extra,
+        extra_positional,
+        arg_spec,
+        vararg_var,
+        kwarg_var,
+    ) = _parse_signature(func)(args, kwargs)
+    values = {}
+    for (name, _has_default, _default), value in zip(arg_spec, args):
+        values[name] = value
+    if vararg_var is not None:
+        values[vararg_var] = tuple(extra_positional)
+    elif extra_positional:
+        raise TypeError("too many positional arguments")
+    if kwarg_var is not None:
+        multikw = set(extra) & set([x[0] for x in arg_spec])
+        if multikw:
+            raise TypeError(
+                "got multiple values for keyword argument " + repr(next(iter(multikw)))
+            )
+        values[kwarg_var] = extra
+    elif extra:
+        raise TypeError("got unexpected keyword argument " + repr(next(iter(extra))))
+    return values
+
+
+class ArgumentValidationError(ValueError):
+
+    """Raised if :func:`validate_arguments` fails to validate"""
+
+    def __init__(self, missing=None, extra=None, extra_positional=None):
+        self.missing = set(missing or ())
+        self.extra = extra or {}
+        self.extra_positional = extra_positional or []
+        ValueError.__init__(
+            self,
+            "function arguments invalid. (%d missing, %d additional)"
+            % (len(self.missing), len(self.extra) + len(self.extra_positional)),
+        )
+
+
+class ImportStringError(ImportError):
+    """Provides information about a failed :func:`import_string` attempt."""
+
+    #: String in dotted notation that failed to be imported.
+    import_name = None
+    #: Wrapped exception.
+    exception = None
+
+    def __init__(self, import_name, exception):
+        self.import_name = import_name
+        self.exception = exception
+
+        msg = (
+            "import_string() failed for %r. Possible reasons are:\n\n"
+            "- missing __init__.py in a package;\n"
+            "- package or module path not included in sys.path;\n"
+            "- duplicated package or module name taking precedence in "
+            "sys.path;\n"
+            "- missing module, class, function or variable;\n\n"
+            "Debugged import:\n\n%s\n\n"
+            "Original exception:\n\n%s: %s"
+        )
+
+        name = ""
+        tracked = []
+        for part in import_name.replace(":", ".").split("."):
+            name += (name and ".") + part
+            imported = import_string(name, silent=True)
+            if imported:
+                tracked.append((name, getattr(imported, "__file__", None)))
+            else:
+                track = ["- %r found in %r." % (n, i) for n, i in tracked]
+                track.append("- %r not found." % name)
+                msg = msg % (
+                    import_name,
+                    "\n".join(track),
+                    exception.__class__.__name__,
+                    str(exception),
+                )
+                break
+
+        ImportError.__init__(self, msg)
+
+    def __repr__(self):
+        return "<%s(%r, %r)>" % (
+            self.__class__.__name__,
+            self.import_name,
+            self.exception,
+        )
+
+
+# DEPRECATED
+from .datastructures import CombinedMultiDict as _CombinedMultiDict
+from .datastructures import EnvironHeaders as _EnvironHeaders
+from .datastructures import Headers as _Headers
+from .datastructures import MultiDict as _MultiDict
+from .http import dump_cookie as _dump_cookie
+from .http import parse_cookie as _parse_cookie
+
+
+class MultiDict(_MultiDict):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.utils.MultiDict' has moved to 'werkzeug"
+            ".datastructures.MultiDict' as of version 0.5. This old"
+            " import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(MultiDict, self).__init__(*args, **kwargs)
+
+
+class CombinedMultiDict(_CombinedMultiDict):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.utils.CombinedMultiDict' has moved to 'werkzeug"
+            ".datastructures.CombinedMultiDict' as of version 0.5. This"
+            " old import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(CombinedMultiDict, self).__init__(*args, **kwargs)
+
+
+class Headers(_Headers):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.utils.Headers' has moved to 'werkzeug"
+            ".datastructures.Headers' as of version 0.5. This old"
+            " import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(Headers, self).__init__(*args, **kwargs)
+
+
+class EnvironHeaders(_EnvironHeaders):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.utils.EnvironHeaders' has moved to 'werkzeug"
+            ".datastructures.EnvironHeaders' as of version 0.5. This"
+            " old import will be removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(EnvironHeaders, self).__init__(*args, **kwargs)
+
+
+def parse_cookie(*args, **kwargs):
+    warnings.warn(
+        "'werkzeug.utils.parse_cookie' as moved to 'werkzeug.http"
+        ".parse_cookie' as of version 0.5. This old import will be"
+        " removed in version 1.0.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    return _parse_cookie(*args, **kwargs)
+
+
+def dump_cookie(*args, **kwargs):
+    warnings.warn(
+        "'werkzeug.utils.dump_cookie' as moved to 'werkzeug.http"
+        ".dump_cookie' as of version 0.5. This old import will be"
+        " removed in version 1.0.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    return _dump_cookie(*args, **kwargs)
diff --git a/python/werkzeug/wrappers/__init__.py b/python/werkzeug/wrappers/__init__.py
new file mode 100644
index 0000000..56c764a
--- /dev/null
+++ b/python/werkzeug/wrappers/__init__.py
@@ -0,0 +1,36 @@
+"""
+werkzeug.wrappers
+~~~~~~~~~~~~~~~~~
+
+The wrappers are simple request and response objects which you can
+subclass to do whatever you want them to do.  The request object contains
+the information transmitted by the client (webbrowser) and the response
+object contains all the information sent back to the browser.
+
+An important detail is that the request object is created with the WSGI
+environ and will act as high-level proxy whereas the response object is an
+actual WSGI application.
+
+Like everything else in Werkzeug these objects will work correctly with
+unicode data.  Incoming form data parsed by the response object will be
+decoded into an unicode object if possible and if it makes sense.
+
+:copyright: 2007 Pallets
+:license: BSD-3-Clause
+"""
+from .accept import AcceptMixin
+from .auth import AuthorizationMixin
+from .auth import WWWAuthenticateMixin
+from .base_request import BaseRequest
+from .base_response import BaseResponse
+from .common_descriptors import CommonRequestDescriptorsMixin
+from .common_descriptors import CommonResponseDescriptorsMixin
+from .etag import ETagRequestMixin
+from .etag import ETagResponseMixin
+from .request import PlainRequest
+from .request import Request
+from .request import StreamOnlyMixin
+from .response import Response
+from .response import ResponseStream
+from .response import ResponseStreamMixin
+from .user_agent import UserAgentMixin
diff --git a/python/werkzeug/wrappers/accept.py b/python/werkzeug/wrappers/accept.py
new file mode 100644
index 0000000..d0620a0
--- /dev/null
+++ b/python/werkzeug/wrappers/accept.py
@@ -0,0 +1,50 @@
+from ..datastructures import CharsetAccept
+from ..datastructures import LanguageAccept
+from ..datastructures import MIMEAccept
+from ..http import parse_accept_header
+from ..utils import cached_property
+
+
+class AcceptMixin(object):
+    """A mixin for classes with an :attr:`~BaseResponse.environ` attribute
+    to get all the HTTP accept headers as
+    :class:`~werkzeug.datastructures.Accept` objects (or subclasses
+    thereof).
+    """
+
+    @cached_property
+    def accept_mimetypes(self):
+        """List of mimetypes this client supports as
+        :class:`~werkzeug.datastructures.MIMEAccept` object.
+        """
+        return parse_accept_header(self.environ.get("HTTP_ACCEPT"), MIMEAccept)
+
+    @cached_property
+    def accept_charsets(self):
+        """List of charsets this client supports as
+        :class:`~werkzeug.datastructures.CharsetAccept` object.
+        """
+        return parse_accept_header(
+            self.environ.get("HTTP_ACCEPT_CHARSET"), CharsetAccept
+        )
+
+    @cached_property
+    def accept_encodings(self):
+        """List of encodings this client accepts.  Encodings in a HTTP term
+        are compression encodings such as gzip.  For charsets have a look at
+        :attr:`accept_charset`.
+        """
+        return parse_accept_header(self.environ.get("HTTP_ACCEPT_ENCODING"))
+
+    @cached_property
+    def accept_languages(self):
+        """List of languages this client accepts as
+        :class:`~werkzeug.datastructures.LanguageAccept` object.
+
+        .. versionchanged 0.5
+           In previous versions this was a regular
+           :class:`~werkzeug.datastructures.Accept` object.
+        """
+        return parse_accept_header(
+            self.environ.get("HTTP_ACCEPT_LANGUAGE"), LanguageAccept
+        )
diff --git a/python/werkzeug/wrappers/auth.py b/python/werkzeug/wrappers/auth.py
new file mode 100644
index 0000000..714f755
--- /dev/null
+++ b/python/werkzeug/wrappers/auth.py
@@ -0,0 +1,33 @@
+from ..http import parse_authorization_header
+from ..http import parse_www_authenticate_header
+from ..utils import cached_property
+
+
+class AuthorizationMixin(object):
+    """Adds an :attr:`authorization` property that represents the parsed
+    value of the `Authorization` header as
+    :class:`~werkzeug.datastructures.Authorization` object.
+    """
+
+    @cached_property
+    def authorization(self):
+        """The `Authorization` object in parsed form."""
+        header = self.environ.get("HTTP_AUTHORIZATION")
+        return parse_authorization_header(header)
+
+
+class WWWAuthenticateMixin(object):
+    """Adds a :attr:`www_authenticate` property to a response object."""
+
+    @property
+    def www_authenticate(self):
+        """The `WWW-Authenticate` header in a parsed form."""
+
+        def on_update(www_auth):
+            if not www_auth and "www-authenticate" in self.headers:
+                del self.headers["www-authenticate"]
+            elif www_auth:
+                self.headers["WWW-Authenticate"] = www_auth.to_header()
+
+        header = self.headers.get("www-authenticate")
+        return parse_www_authenticate_header(header, on_update)
diff --git a/python/werkzeug/wrappers/base_request.py b/python/werkzeug/wrappers/base_request.py
new file mode 100644
index 0000000..41e8aad
--- /dev/null
+++ b/python/werkzeug/wrappers/base_request.py
@@ -0,0 +1,693 @@
+import warnings
+from functools import update_wrapper
+from io import BytesIO
+
+from .._compat import to_native
+from .._compat import to_unicode
+from .._compat import wsgi_decoding_dance
+from .._compat import wsgi_get_bytes
+from ..datastructures import CombinedMultiDict
+from ..datastructures import EnvironHeaders
+from ..datastructures import ImmutableList
+from ..datastructures import ImmutableMultiDict
+from ..datastructures import ImmutableTypeConversionDict
+from ..datastructures import iter_multi_items
+from ..datastructures import MultiDict
+from ..formparser import default_stream_factory
+from ..formparser import FormDataParser
+from ..http import parse_cookie
+from ..http import parse_options_header
+from ..urls import url_decode
+from ..utils import cached_property
+from ..utils import environ_property
+from ..wsgi import get_content_length
+from ..wsgi import get_current_url
+from ..wsgi import get_host
+from ..wsgi import get_input_stream
+
+
+class BaseRequest(object):
+    """Very basic request object.  This does not implement advanced stuff like
+    entity tag parsing or cache controls.  The request object is created with
+    the WSGI environment as first argument and will add itself to the WSGI
+    environment as ``'werkzeug.request'`` unless it's created with
+    `populate_request` set to False.
+
+    There are a couple of mixins available that add additional functionality
+    to the request object, there is also a class called `Request` which
+    subclasses `BaseRequest` and all the important mixins.
+
+    It's a good idea to create a custom subclass of the :class:`BaseRequest`
+    and add missing functionality either via mixins or direct implementation.
+    Here an example for such subclasses::
+
+        from werkzeug.wrappers import BaseRequest, ETagRequestMixin
+
+        class Request(BaseRequest, ETagRequestMixin):
+            pass
+
+    Request objects are **read only**.  As of 0.5 modifications are not
+    allowed in any place.  Unlike the lower level parsing functions the
+    request object will use immutable objects everywhere possible.
+
+    Per default the request object will assume all the text data is `utf-8`
+    encoded.  Please refer to :doc:`the unicode chapter </unicode>` for more
+    details about customizing the behavior.
+
+    Per default the request object will be added to the WSGI
+    environment as `werkzeug.request` to support the debugging system.
+    If you don't want that, set `populate_request` to `False`.
+
+    If `shallow` is `True` the environment is initialized as shallow
+    object around the environ.  Every operation that would modify the
+    environ in any way (such as consuming form data) raises an exception
+    unless the `shallow` attribute is explicitly set to `False`.  This
+    is useful for middlewares where you don't want to consume the form
+    data by accident.  A shallow request is not populated to the WSGI
+    environment.
+
+    .. versionchanged:: 0.5
+       read-only mode was enforced by using immutables classes for all
+       data.
+    """
+
+    #: the charset for the request, defaults to utf-8
+    charset = "utf-8"
+
+    #: the error handling procedure for errors, defaults to 'replace'
+    encoding_errors = "replace"
+
+    #: the maximum content length.  This is forwarded to the form data
+    #: parsing function (:func:`parse_form_data`).  When set and the
+    #: :attr:`form` or :attr:`files` attribute is accessed and the
+    #: parsing fails because more than the specified value is transmitted
+    #: a :exc:`~werkzeug.exceptions.RequestEntityTooLarge` exception is raised.
+    #:
+    #: Have a look at :ref:`dealing-with-request-data` for more details.
+    #:
+    #: .. versionadded:: 0.5
+    max_content_length = None
+
+    #: the maximum form field size.  This is forwarded to the form data
+    #: parsing function (:func:`parse_form_data`).  When set and the
+    #: :attr:`form` or :attr:`files` attribute is accessed and the
+    #: data in memory for post data is longer than the specified value a
+    #: :exc:`~werkzeug.exceptions.RequestEntityTooLarge` exception is raised.
+    #:
+    #: Have a look at :ref:`dealing-with-request-data` for more details.
+    #:
+    #: .. versionadded:: 0.5
+    max_form_memory_size = None
+
+    #: the class to use for `args` and `form`.  The default is an
+    #: :class:`~werkzeug.datastructures.ImmutableMultiDict` which supports
+    #: multiple values per key.  alternatively it makes sense to use an
+    #: :class:`~werkzeug.datastructures.ImmutableOrderedMultiDict` which
+    #: preserves order or a :class:`~werkzeug.datastructures.ImmutableDict`
+    #: which is the fastest but only remembers the last key.  It is also
+    #: possible to use mutable structures, but this is not recommended.
+    #:
+    #: .. versionadded:: 0.6
+    parameter_storage_class = ImmutableMultiDict
+
+    #: the type to be used for list values from the incoming WSGI environment.
+    #: By default an :class:`~werkzeug.datastructures.ImmutableList` is used
+    #: (for example for :attr:`access_list`).
+    #:
+    #: .. versionadded:: 0.6
+    list_storage_class = ImmutableList
+
+    #: the type to be used for dict values from the incoming WSGI environment.
+    #: By default an
+    #: :class:`~werkzeug.datastructures.ImmutableTypeConversionDict` is used
+    #: (for example for :attr:`cookies`).
+    #:
+    #: .. versionadded:: 0.6
+    dict_storage_class = ImmutableTypeConversionDict
+
+    #: The form data parser that shoud be used.  Can be replaced to customize
+    #: the form date parsing.
+    form_data_parser_class = FormDataParser
+
+    #: Optionally a list of hosts that is trusted by this request.  By default
+    #: all hosts are trusted which means that whatever the client sends the
+    #: host is will be accepted.
+    #:
+    #: Because `Host` and `X-Forwarded-Host` headers can be set to any value by
+    #: a malicious client, it is recommended to either set this property or
+    #: implement similar validation in the proxy (if application is being run
+    #: behind one).
+    #:
+    #: .. versionadded:: 0.9
+    trusted_hosts = None
+
+    #: Indicates whether the data descriptor should be allowed to read and
+    #: buffer up the input stream.  By default it's enabled.
+    #:
+    #: .. versionadded:: 0.9
+    disable_data_descriptor = False
+
+    def __init__(self, environ, populate_request=True, shallow=False):
+        self.environ = environ
+        if populate_request and not shallow:
+            self.environ["werkzeug.request"] = self
+        self.shallow = shallow
+
+    def __repr__(self):
+        # make sure the __repr__ even works if the request was created
+        # from an invalid WSGI environment.  If we display the request
+        # in a debug session we don't want the repr to blow up.
+        args = []
+        try:
+            args.append("'%s'" % to_native(self.url, self.url_charset))
+            args.append("[%s]" % self.method)
+        except Exception:
+            args.append("(invalid WSGI environ)")
+
+        return "<%s %s>" % (self.__class__.__name__, " ".join(args))
+
+    @property
+    def url_charset(self):
+        """The charset that is assumed for URLs.  Defaults to the value
+        of :attr:`charset`.
+
+        .. versionadded:: 0.6
+        """
+        return self.charset
+
+    @classmethod
+    def from_values(cls, *args, **kwargs):
+        """Create a new request object based on the values provided.  If
+        environ is given missing values are filled from there.  This method is
+        useful for small scripts when you need to simulate a request from an URL.
+        Do not use this method for unittesting, there is a full featured client
+        object (:class:`Client`) that allows to create multipart requests,
+        support for cookies etc.
+
+        This accepts the same options as the
+        :class:`~werkzeug.test.EnvironBuilder`.
+
+        .. versionchanged:: 0.5
+           This method now accepts the same arguments as
+           :class:`~werkzeug.test.EnvironBuilder`.  Because of this the
+           `environ` parameter is now called `environ_overrides`.
+
+        :return: request object
+        """
+        from ..test import EnvironBuilder
+
+        charset = kwargs.pop("charset", cls.charset)
+        kwargs["charset"] = charset
+        builder = EnvironBuilder(*args, **kwargs)
+        try:
+            return builder.get_request(cls)
+        finally:
+            builder.close()
+
+    @classmethod
+    def application(cls, f):
+        """Decorate a function as responder that accepts the request as first
+        argument.  This works like the :func:`responder` decorator but the
+        function is passed the request object as first argument and the
+        request object will be closed automatically::
+
+            @Request.application
+            def my_wsgi_app(request):
+                return Response('Hello World!')
+
+        As of Werkzeug 0.14 HTTP exceptions are automatically caught and
+        converted to responses instead of failing.
+
+        :param f: the WSGI callable to decorate
+        :return: a new WSGI callable
+        """
+        #: return a callable that wraps the -2nd argument with the request
+        #: and calls the function with all the arguments up to that one and
+        #: the request.  The return value is then called with the latest
+        #: two arguments.  This makes it possible to use this decorator for
+        #: both methods and standalone WSGI functions.
+        from ..exceptions import HTTPException
+
+        def application(*args):
+            request = cls(args[-2])
+            with request:
+                try:
+                    resp = f(*args[:-2] + (request,))
+                except HTTPException as e:
+                    resp = e.get_response(args[-2])
+                return resp(*args[-2:])
+
+        return update_wrapper(application, f)
+
+    def _get_file_stream(
+        self, total_content_length, content_type, filename=None, content_length=None
+    ):
+        """Called to get a stream for the file upload.
+
+        This must provide a file-like class with `read()`, `readline()`
+        and `seek()` methods that is both writeable and readable.
+
+        The default implementation returns a temporary file if the total
+        content length is higher than 500KB.  Because many browsers do not
+        provide a content length for the files only the total content
+        length matters.
+
+        :param total_content_length: the total content length of all the
+                                     data in the request combined.  This value
+                                     is guaranteed to be there.
+        :param content_type: the mimetype of the uploaded file.
+        :param filename: the filename of the uploaded file.  May be `None`.
+        :param content_length: the length of this file.  This value is usually
+                               not provided because webbrowsers do not provide
+                               this value.
+        """
+        return default_stream_factory(
+            total_content_length=total_content_length,
+            filename=filename,
+            content_type=content_type,
+            content_length=content_length,
+        )
+
+    @property
+    def want_form_data_parsed(self):
+        """Returns True if the request method carries content.  As of
+        Werkzeug 0.9 this will be the case if a content type is transmitted.
+
+        .. versionadded:: 0.8
+        """
+        return bool(self.environ.get("CONTENT_TYPE"))
+
+    def make_form_data_parser(self):
+        """Creates the form data parser. Instantiates the
+        :attr:`form_data_parser_class` with some parameters.
+
+        .. versionadded:: 0.8
+        """
+        return self.form_data_parser_class(
+            self._get_file_stream,
+            self.charset,
+            self.encoding_errors,
+            self.max_form_memory_size,
+            self.max_content_length,
+            self.parameter_storage_class,
+        )
+
+    def _load_form_data(self):
+        """Method used internally to retrieve submitted data.  After calling
+        this sets `form` and `files` on the request object to multi dicts
+        filled with the incoming form data.  As a matter of fact the input
+        stream will be empty afterwards.  You can also call this method to
+        force the parsing of the form data.
+
+        .. versionadded:: 0.8
+        """
+        # abort early if we have already consumed the stream
+        if "form" in self.__dict__:
+            return
+
+        _assert_not_shallow(self)
+
+        if self.want_form_data_parsed:
+            content_type = self.environ.get("CONTENT_TYPE", "")
+            content_length = get_content_length(self.environ)
+            mimetype, options = parse_options_header(content_type)
+            parser = self.make_form_data_parser()
+            data = parser.parse(
+                self._get_stream_for_parsing(), mimetype, content_length, options
+            )
+        else:
+            data = (
+                self.stream,
+                self.parameter_storage_class(),
+                self.parameter_storage_class(),
+            )
+
+        # inject the values into the instance dict so that we bypass
+        # our cached_property non-data descriptor.
+        d = self.__dict__
+        d["stream"], d["form"], d["files"] = data
+
+    def _get_stream_for_parsing(self):
+        """This is the same as accessing :attr:`stream` with the difference
+        that if it finds cached data from calling :meth:`get_data` first it
+        will create a new stream out of the cached data.
+
+        .. versionadded:: 0.9.3
+        """
+        cached_data = getattr(self, "_cached_data", None)
+        if cached_data is not None:
+            return BytesIO(cached_data)
+        return self.stream
+
+    def close(self):
+        """Closes associated resources of this request object.  This
+        closes all file handles explicitly.  You can also use the request
+        object in a with statement which will automatically close it.
+
+        .. versionadded:: 0.9
+        """
+        files = self.__dict__.get("files")
+        for _key, value in iter_multi_items(files or ()):
+            value.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, tb):
+        self.close()
+
+    @cached_property
+    def stream(self):
+        """
+        If the incoming form data was not encoded with a known mimetype
+        the data is stored unmodified in this stream for consumption.  Most
+        of the time it is a better idea to use :attr:`data` which will give
+        you that data as a string.  The stream only returns the data once.
+
+        Unlike :attr:`input_stream` this stream is properly guarded that you
+        can't accidentally read past the length of the input.  Werkzeug will
+        internally always refer to this stream to read data which makes it
+        possible to wrap this object with a stream that does filtering.
+
+        .. versionchanged:: 0.9
+           This stream is now always available but might be consumed by the
+           form parser later on.  Previously the stream was only set if no
+           parsing happened.
+        """
+        _assert_not_shallow(self)
+        return get_input_stream(self.environ)
+
+    input_stream = environ_property(
+        "wsgi.input",
+        """The WSGI input stream.
+
+        In general it's a bad idea to use this one because you can
+        easily read past the boundary.  Use the :attr:`stream`
+        instead.""",
+    )
+
+    @cached_property
+    def args(self):
+        """The parsed URL parameters (the part in the URL after the question
+        mark).
+
+        By default an
+        :class:`~werkzeug.datastructures.ImmutableMultiDict`
+        is returned from this function.  This can be changed by setting
+        :attr:`parameter_storage_class` to a different type.  This might
+        be necessary if the order of the form data is important.
+        """
+        return url_decode(
+            wsgi_get_bytes(self.environ.get("QUERY_STRING", "")),
+            self.url_charset,
+            errors=self.encoding_errors,
+            cls=self.parameter_storage_class,
+        )
+
+    @cached_property
+    def data(self):
+        """
+        Contains the incoming request data as string in case it came with
+        a mimetype Werkzeug does not handle.
+        """
+
+        if self.disable_data_descriptor:
+            raise AttributeError("data descriptor is disabled")
+        # XXX: this should eventually be deprecated.
+
+        # We trigger form data parsing first which means that the descriptor
+        # will not cache the data that would otherwise be .form or .files
+        # data.  This restores the behavior that was there in Werkzeug
+        # before 0.9.  New code should use :meth:`get_data` explicitly as
+        # this will make behavior explicit.
+        return self.get_data(parse_form_data=True)
+
+    def get_data(self, cache=True, as_text=False, parse_form_data=False):
+        """This reads the buffered incoming data from the client into one
+        bytestring.  By default this is cached but that behavior can be
+        changed by setting `cache` to `False`.
+
+        Usually it's a bad idea to call this method without checking the
+        content length first as a client could send dozens of megabytes or more
+        to cause memory problems on the server.
+
+        Note that if the form data was already parsed this method will not
+        return anything as form data parsing does not cache the data like
+        this method does.  To implicitly invoke form data parsing function
+        set `parse_form_data` to `True`.  When this is done the return value
+        of this method will be an empty string if the form parser handles
+        the data.  This generally is not necessary as if the whole data is
+        cached (which is the default) the form parser will used the cached
+        data to parse the form data.  Please be generally aware of checking
+        the content length first in any case before calling this method
+        to avoid exhausting server memory.
+
+        If `as_text` is set to `True` the return value will be a decoded
+        unicode string.
+
+        .. versionadded:: 0.9
+        """
+        rv = getattr(self, "_cached_data", None)
+        if rv is None:
+            if parse_form_data:
+                self._load_form_data()
+            rv = self.stream.read()
+            if cache:
+                self._cached_data = rv
+        if as_text:
+            rv = rv.decode(self.charset, self.encoding_errors)
+        return rv
+
+    @cached_property
+    def form(self):
+        """The form parameters.  By default an
+        :class:`~werkzeug.datastructures.ImmutableMultiDict`
+        is returned from this function.  This can be changed by setting
+        :attr:`parameter_storage_class` to a different type.  This might
+        be necessary if the order of the form data is important.
+
+        Please keep in mind that file uploads will not end up here, but instead
+        in the :attr:`files` attribute.
+
+        .. versionchanged:: 0.9
+
+            Previous to Werkzeug 0.9 this would only contain form data for POST
+            and PUT requests.
+        """
+        self._load_form_data()
+        return self.form
+
+    @cached_property
+    def values(self):
+        """A :class:`werkzeug.datastructures.CombinedMultiDict` that combines
+        :attr:`args` and :attr:`form`."""
+        args = []
+        for d in self.args, self.form:
+            if not isinstance(d, MultiDict):
+                d = MultiDict(d)
+            args.append(d)
+        return CombinedMultiDict(args)
+
+    @cached_property
+    def files(self):
+        """:class:`~werkzeug.datastructures.MultiDict` object containing
+        all uploaded files.  Each key in :attr:`files` is the name from the
+        ``<input type="file" name="">``.  Each value in :attr:`files` is a
+        Werkzeug :class:`~werkzeug.datastructures.FileStorage` object.
+
+        It basically behaves like a standard file object you know from Python,
+        with the difference that it also has a
+        :meth:`~werkzeug.datastructures.FileStorage.save` function that can
+        store the file on the filesystem.
+
+        Note that :attr:`files` will only contain data if the request method was
+        POST, PUT or PATCH and the ``<form>`` that posted to the request had
+        ``enctype="multipart/form-data"``.  It will be empty otherwise.
+
+        See the :class:`~werkzeug.datastructures.MultiDict` /
+        :class:`~werkzeug.datastructures.FileStorage` documentation for
+        more details about the used data structure.
+        """
+        self._load_form_data()
+        return self.files
+
+    @cached_property
+    def cookies(self):
+        """A :class:`dict` with the contents of all cookies transmitted with
+        the request."""
+        return parse_cookie(
+            self.environ,
+            self.charset,
+            self.encoding_errors,
+            cls=self.dict_storage_class,
+        )
+
+    @cached_property
+    def headers(self):
+        """The headers from the WSGI environ as immutable
+        :class:`~werkzeug.datastructures.EnvironHeaders`.
+        """
+        return EnvironHeaders(self.environ)
+
+    @cached_property
+    def path(self):
+        """Requested path as unicode.  This works a bit like the regular path
+        info in the WSGI environment but will always include a leading slash,
+        even if the URL root is accessed.
+        """
+        raw_path = wsgi_decoding_dance(
+            self.environ.get("PATH_INFO") or "", self.charset, self.encoding_errors
+        )
+        return "/" + raw_path.lstrip("/")
+
+    @cached_property
+    def full_path(self):
+        """Requested path as unicode, including the query string."""
+        return self.path + u"?" + to_unicode(self.query_string, self.url_charset)
+
+    @cached_property
+    def script_root(self):
+        """The root path of the script without the trailing slash."""
+        raw_path = wsgi_decoding_dance(
+            self.environ.get("SCRIPT_NAME") or "", self.charset, self.encoding_errors
+        )
+        return raw_path.rstrip("/")
+
+    @cached_property
+    def url(self):
+        """The reconstructed current URL as IRI.
+        See also: :attr:`trusted_hosts`.
+        """
+        return get_current_url(self.environ, trusted_hosts=self.trusted_hosts)
+
+    @cached_property
+    def base_url(self):
+        """Like :attr:`url` but without the querystring
+        See also: :attr:`trusted_hosts`.
+        """
+        return get_current_url(
+            self.environ, strip_querystring=True, trusted_hosts=self.trusted_hosts
+        )
+
+    @cached_property
+    def url_root(self):
+        """The full URL root (with hostname), this is the application
+        root as IRI.
+        See also: :attr:`trusted_hosts`.
+        """
+        return get_current_url(self.environ, True, trusted_hosts=self.trusted_hosts)
+
+    @cached_property
+    def host_url(self):
+        """Just the host with scheme as IRI.
+        See also: :attr:`trusted_hosts`.
+        """
+        return get_current_url(
+            self.environ, host_only=True, trusted_hosts=self.trusted_hosts
+        )
+
+    @cached_property
+    def host(self):
+        """Just the host including the port if available.
+        See also: :attr:`trusted_hosts`.
+        """
+        return get_host(self.environ, trusted_hosts=self.trusted_hosts)
+
+    query_string = environ_property(
+        "QUERY_STRING",
+        "",
+        read_only=True,
+        load_func=wsgi_get_bytes,
+        doc="The URL parameters as raw bytestring.",
+    )
+    method = environ_property(
+        "REQUEST_METHOD",
+        "GET",
+        read_only=True,
+        load_func=lambda x: x.upper(),
+        doc="The request method. (For example ``'GET'`` or ``'POST'``).",
+    )
+
+    @cached_property
+    def access_route(self):
+        """If a forwarded header exists this is a list of all ip addresses
+        from the client ip to the last proxy server.
+        """
+        if "HTTP_X_FORWARDED_FOR" in self.environ:
+            addr = self.environ["HTTP_X_FORWARDED_FOR"].split(",")
+            return self.list_storage_class([x.strip() for x in addr])
+        elif "REMOTE_ADDR" in self.environ:
+            return self.list_storage_class([self.environ["REMOTE_ADDR"]])
+        return self.list_storage_class()
+
+    @property
+    def remote_addr(self):
+        """The remote address of the client."""
+        return self.environ.get("REMOTE_ADDR")
+
+    remote_user = environ_property(
+        "REMOTE_USER",
+        doc="""If the server supports user authentication, and the
+        script is protected, this attribute contains the username the
+        user has authenticated as.""",
+    )
+
+    scheme = environ_property(
+        "wsgi.url_scheme",
+        doc="""
+        URL scheme (http or https).
+
+        .. versionadded:: 0.7""",
+    )
+
+    @property
+    def is_xhr(self):
+        """True if the request was triggered via a JavaScript XMLHttpRequest.
+        This only works with libraries that support the ``X-Requested-With``
+        header and set it to "XMLHttpRequest".  Libraries that do that are
+        prototype, jQuery and Mochikit and probably some more.
+
+        .. deprecated:: 0.13
+            ``X-Requested-With`` is not standard and is unreliable. You
+            may be able to use :attr:`AcceptMixin.accept_mimetypes`
+            instead.
+        """
+        warnings.warn(
+            "'Request.is_xhr' is deprecated as of version 0.13 and will"
+            " be removed in version 1.0. The 'X-Requested-With' header"
+            " is not standard and is unreliable. You may be able to use"
+            " 'accept_mimetypes' instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return self.environ.get("HTTP_X_REQUESTED_WITH", "").lower() == "xmlhttprequest"
+
+    is_secure = property(
+        lambda self: self.environ["wsgi.url_scheme"] == "https",
+        doc="`True` if the request is secure.",
+    )
+    is_multithread = environ_property(
+        "wsgi.multithread",
+        doc="""boolean that is `True` if the application is served by a
+        multithreaded WSGI server.""",
+    )
+    is_multiprocess = environ_property(
+        "wsgi.multiprocess",
+        doc="""boolean that is `True` if the application is served by a
+        WSGI server that spawns multiple processes.""",
+    )
+    is_run_once = environ_property(
+        "wsgi.run_once",
+        doc="""boolean that is `True` if the application will be
+        executed only once in a process lifetime.  This is the case for
+        CGI for example, but it's not guaranteed that the execution only
+        happens one time.""",
+    )
+
+
+def _assert_not_shallow(request):
+    if request.shallow:
+        raise RuntimeError(
+            "A shallow request tried to consume form data. If you really"
+            " want to do that, set `shallow` to False."
+        )
diff --git a/python/werkzeug/wrappers/base_response.py b/python/werkzeug/wrappers/base_response.py
new file mode 100644
index 0000000..d944a7d
--- /dev/null
+++ b/python/werkzeug/wrappers/base_response.py
@@ -0,0 +1,702 @@
+import warnings
+
+from .._compat import integer_types
+from .._compat import string_types
+from .._compat import text_type
+from .._compat import to_bytes
+from .._compat import to_native
+from ..datastructures import Headers
+from ..http import dump_cookie
+from ..http import HTTP_STATUS_CODES
+from ..http import remove_entity_headers
+from ..urls import iri_to_uri
+from ..urls import url_join
+from ..utils import get_content_type
+from ..wsgi import ClosingIterator
+from ..wsgi import get_current_url
+
+
+def _run_wsgi_app(*args):
+    """This function replaces itself to ensure that the test module is not
+    imported unless required.  DO NOT USE!
+    """
+    global _run_wsgi_app
+    from ..test import run_wsgi_app as _run_wsgi_app
+
+    return _run_wsgi_app(*args)
+
+
+def _warn_if_string(iterable):
+    """Helper for the response objects to check if the iterable returned
+    to the WSGI server is not a string.
+    """
+    if isinstance(iterable, string_types):
+        warnings.warn(
+            "Response iterable was set to a string. This will appear to"
+            " work but means that the server will send the data to the"
+            " client one character at a time. This is almost never"
+            " intended behavior, use 'response.data' to assign strings"
+            " to the response object.",
+            stacklevel=2,
+        )
+
+
+def _iter_encoded(iterable, charset):
+    for item in iterable:
+        if isinstance(item, text_type):
+            yield item.encode(charset)
+        else:
+            yield item
+
+
+def _clean_accept_ranges(accept_ranges):
+    if accept_ranges is True:
+        return "bytes"
+    elif accept_ranges is False:
+        return "none"
+    elif isinstance(accept_ranges, text_type):
+        return to_native(accept_ranges)
+    raise ValueError("Invalid accept_ranges value")
+
+
+class BaseResponse(object):
+    """Base response class.  The most important fact about a response object
+    is that it's a regular WSGI application.  It's initialized with a couple
+    of response parameters (headers, body, status code etc.) and will start a
+    valid WSGI response when called with the environ and start response
+    callable.
+
+    Because it's a WSGI application itself processing usually ends before the
+    actual response is sent to the server.  This helps debugging systems
+    because they can catch all the exceptions before responses are started.
+
+    Here a small example WSGI application that takes advantage of the
+    response objects::
+
+        from werkzeug.wrappers import BaseResponse as Response
+
+        def index():
+            return Response('Index page')
+
+        def application(environ, start_response):
+            path = environ.get('PATH_INFO') or '/'
+            if path == '/':
+                response = index()
+            else:
+                response = Response('Not Found', status=404)
+            return response(environ, start_response)
+
+    Like :class:`BaseRequest` which object is lacking a lot of functionality
+    implemented in mixins.  This gives you a better control about the actual
+    API of your response objects, so you can create subclasses and add custom
+    functionality.  A full featured response object is available as
+    :class:`Response` which implements a couple of useful mixins.
+
+    To enforce a new type of already existing responses you can use the
+    :meth:`force_type` method.  This is useful if you're working with different
+    subclasses of response objects and you want to post process them with a
+    known interface.
+
+    Per default the response object will assume all the text data is `utf-8`
+    encoded.  Please refer to :doc:`the unicode chapter </unicode>` for more
+    details about customizing the behavior.
+
+    Response can be any kind of iterable or string.  If it's a string it's
+    considered being an iterable with one item which is the string passed.
+    Headers can be a list of tuples or a
+    :class:`~werkzeug.datastructures.Headers` object.
+
+    Special note for `mimetype` and `content_type`:  For most mime types
+    `mimetype` and `content_type` work the same, the difference affects
+    only 'text' mimetypes.  If the mimetype passed with `mimetype` is a
+    mimetype starting with `text/`, the charset parameter of the response
+    object is appended to it.  In contrast the `content_type` parameter is
+    always added as header unmodified.
+
+    .. versionchanged:: 0.5
+       the `direct_passthrough` parameter was added.
+
+    :param response: a string or response iterable.
+    :param status: a string with a status or an integer with the status code.
+    :param headers: a list of headers or a
+                    :class:`~werkzeug.datastructures.Headers` object.
+    :param mimetype: the mimetype for the response.  See notice above.
+    :param content_type: the content type for the response.  See notice above.
+    :param direct_passthrough: if set to `True` :meth:`iter_encoded` is not
+                               called before iteration which makes it
+                               possible to pass special iterators through
+                               unchanged (see :func:`wrap_file` for more
+                               details.)
+    """
+
+    #: the charset of the response.
+    charset = "utf-8"
+
+    #: the default status if none is provided.
+    default_status = 200
+
+    #: the default mimetype if none is provided.
+    default_mimetype = "text/plain"
+
+    #: if set to `False` accessing properties on the response object will
+    #: not try to consume the response iterator and convert it into a list.
+    #:
+    #: .. versionadded:: 0.6.2
+    #:
+    #:    That attribute was previously called `implicit_seqence_conversion`.
+    #:    (Notice the typo).  If you did use this feature, you have to adapt
+    #:    your code to the name change.
+    implicit_sequence_conversion = True
+
+    #: Should this response object correct the location header to be RFC
+    #: conformant?  This is true by default.
+    #:
+    #: .. versionadded:: 0.8
+    autocorrect_location_header = True
+
+    #: Should this response object automatically set the content-length
+    #: header if possible?  This is true by default.
+    #:
+    #: .. versionadded:: 0.8
+    automatically_set_content_length = True
+
+    #: Warn if a cookie header exceeds this size. The default, 4093, should be
+    #: safely `supported by most browsers <cookie_>`_. A cookie larger than
+    #: this size will still be sent, but it may be ignored or handled
+    #: incorrectly by some browsers. Set to 0 to disable this check.
+    #:
+    #: .. versionadded:: 0.13
+    #:
+    #: .. _`cookie`: http://browsercookielimits.squawky.net/
+    max_cookie_size = 4093
+
+    def __init__(
+        self,
+        response=None,
+        status=None,
+        headers=None,
+        mimetype=None,
+        content_type=None,
+        direct_passthrough=False,
+    ):
+        if isinstance(headers, Headers):
+            self.headers = headers
+        elif not headers:
+            self.headers = Headers()
+        else:
+            self.headers = Headers(headers)
+
+        if content_type is None:
+            if mimetype is None and "content-type" not in self.headers:
+                mimetype = self.default_mimetype
+            if mimetype is not None:
+                mimetype = get_content_type(mimetype, self.charset)
+            content_type = mimetype
+        if content_type is not None:
+            self.headers["Content-Type"] = content_type
+        if status is None:
+            status = self.default_status
+        if isinstance(status, integer_types):
+            self.status_code = status
+        else:
+            self.status = status
+
+        self.direct_passthrough = direct_passthrough
+        self._on_close = []
+
+        # we set the response after the headers so that if a class changes
+        # the charset attribute, the data is set in the correct charset.
+        if response is None:
+            self.response = []
+        elif isinstance(response, (text_type, bytes, bytearray)):
+            self.set_data(response)
+        else:
+            self.response = response
+
+    def call_on_close(self, func):
+        """Adds a function to the internal list of functions that should
+        be called as part of closing down the response.  Since 0.7 this
+        function also returns the function that was passed so that this
+        can be used as a decorator.
+
+        .. versionadded:: 0.6
+        """
+        self._on_close.append(func)
+        return func
+
+    def __repr__(self):
+        if self.is_sequence:
+            body_info = "%d bytes" % sum(map(len, self.iter_encoded()))
+        else:
+            body_info = "streamed" if self.is_streamed else "likely-streamed"
+        return "<%s %s [%s]>" % (self.__class__.__name__, body_info, self.status)
+
+    @classmethod
+    def force_type(cls, response, environ=None):
+        """Enforce that the WSGI response is a response object of the current
+        type.  Werkzeug will use the :class:`BaseResponse` internally in many
+        situations like the exceptions.  If you call :meth:`get_response` on an
+        exception you will get back a regular :class:`BaseResponse` object, even
+        if you are using a custom subclass.
+
+        This method can enforce a given response type, and it will also
+        convert arbitrary WSGI callables into response objects if an environ
+        is provided::
+
+            # convert a Werkzeug response object into an instance of the
+            # MyResponseClass subclass.
+            response = MyResponseClass.force_type(response)
+
+            # convert any WSGI application into a response object
+            response = MyResponseClass.force_type(response, environ)
+
+        This is especially useful if you want to post-process responses in
+        the main dispatcher and use functionality provided by your subclass.
+
+        Keep in mind that this will modify response objects in place if
+        possible!
+
+        :param response: a response object or wsgi application.
+        :param environ: a WSGI environment object.
+        :return: a response object.
+        """
+        if not isinstance(response, BaseResponse):
+            if environ is None:
+                raise TypeError(
+                    "cannot convert WSGI application into response"
+                    " objects without an environ"
+                )
+            response = BaseResponse(*_run_wsgi_app(response, environ))
+        response.__class__ = cls
+        return response
+
+    @classmethod
+    def from_app(cls, app, environ, buffered=False):
+        """Create a new response object from an application output.  This
+        works best if you pass it an application that returns a generator all
+        the time.  Sometimes applications may use the `write()` callable
+        returned by the `start_response` function.  This tries to resolve such
+        edge cases automatically.  But if you don't get the expected output
+        you should set `buffered` to `True` which enforces buffering.
+
+        :param app: the WSGI application to execute.
+        :param environ: the WSGI environment to execute against.
+        :param buffered: set to `True` to enforce buffering.
+        :return: a response object.
+        """
+        return cls(*_run_wsgi_app(app, environ, buffered))
+
+    def _get_status_code(self):
+        return self._status_code
+
+    def _set_status_code(self, code):
+        self._status_code = code
+        try:
+            self._status = "%d %s" % (code, HTTP_STATUS_CODES[code].upper())
+        except KeyError:
+            self._status = "%d UNKNOWN" % code
+
+    status_code = property(
+        _get_status_code, _set_status_code, doc="The HTTP Status code as number"
+    )
+    del _get_status_code, _set_status_code
+
+    def _get_status(self):
+        return self._status
+
+    def _set_status(self, value):
+        try:
+            self._status = to_native(value)
+        except AttributeError:
+            raise TypeError("Invalid status argument")
+
+        try:
+            self._status_code = int(self._status.split(None, 1)[0])
+        except ValueError:
+            self._status_code = 0
+            self._status = "0 %s" % self._status
+        except IndexError:
+            raise ValueError("Empty status argument")
+
+    status = property(_get_status, _set_status, doc="The HTTP Status code")
+    del _get_status, _set_status
+
+    def get_data(self, as_text=False):
+        """The string representation of the request body.  Whenever you call
+        this property the request iterable is encoded and flattened.  This
+        can lead to unwanted behavior if you stream big data.
+
+        This behavior can be disabled by setting
+        :attr:`implicit_sequence_conversion` to `False`.
+
+        If `as_text` is set to `True` the return value will be a decoded
+        unicode string.
+
+        .. versionadded:: 0.9
+        """
+        self._ensure_sequence()
+        rv = b"".join(self.iter_encoded())
+        if as_text:
+            rv = rv.decode(self.charset)
+        return rv
+
+    def set_data(self, value):
+        """Sets a new string as response.  The value set must either by a
+        unicode or bytestring.  If a unicode string is set it's encoded
+        automatically to the charset of the response (utf-8 by default).
+
+        .. versionadded:: 0.9
+        """
+        # if an unicode string is set, it's encoded directly so that we
+        # can set the content length
+        if isinstance(value, text_type):
+            value = value.encode(self.charset)
+        else:
+            value = bytes(value)
+        self.response = [value]
+        if self.automatically_set_content_length:
+            self.headers["Content-Length"] = str(len(value))
+
+    data = property(
+        get_data,
+        set_data,
+        doc="A descriptor that calls :meth:`get_data` and :meth:`set_data`.",
+    )
+
+    def calculate_content_length(self):
+        """Returns the content length if available or `None` otherwise."""
+        try:
+            self._ensure_sequence()
+        except RuntimeError:
+            return None
+        return sum(len(x) for x in self.iter_encoded())
+
+    def _ensure_sequence(self, mutable=False):
+        """This method can be called by methods that need a sequence.  If
+        `mutable` is true, it will also ensure that the response sequence
+        is a standard Python list.
+
+        .. versionadded:: 0.6
+        """
+        if self.is_sequence:
+            # if we need a mutable object, we ensure it's a list.
+            if mutable and not isinstance(self.response, list):
+                self.response = list(self.response)
+            return
+        if self.direct_passthrough:
+            raise RuntimeError(
+                "Attempted implicit sequence conversion but the"
+                " response object is in direct passthrough mode."
+            )
+        if not self.implicit_sequence_conversion:
+            raise RuntimeError(
+                "The response object required the iterable to be a"
+                " sequence, but the implicit conversion was disabled."
+                " Call make_sequence() yourself."
+            )
+        self.make_sequence()
+
+    def make_sequence(self):
+        """Converts the response iterator in a list.  By default this happens
+        automatically if required.  If `implicit_sequence_conversion` is
+        disabled, this method is not automatically called and some properties
+        might raise exceptions.  This also encodes all the items.
+
+        .. versionadded:: 0.6
+        """
+        if not self.is_sequence:
+            # if we consume an iterable we have to ensure that the close
+            # method of the iterable is called if available when we tear
+            # down the response
+            close = getattr(self.response, "close", None)
+            self.response = list(self.iter_encoded())
+            if close is not None:
+                self.call_on_close(close)
+
+    def iter_encoded(self):
+        """Iter the response encoded with the encoding of the response.
+        If the response object is invoked as WSGI application the return
+        value of this method is used as application iterator unless
+        :attr:`direct_passthrough` was activated.
+        """
+        if __debug__:
+            _warn_if_string(self.response)
+        # Encode in a separate function so that self.response is fetched
+        # early.  This allows us to wrap the response with the return
+        # value from get_app_iter or iter_encoded.
+        return _iter_encoded(self.response, self.charset)
+
+    def set_cookie(
+        self,
+        key,
+        value="",
+        max_age=None,
+        expires=None,
+        path="/",
+        domain=None,
+        secure=False,
+        httponly=False,
+        samesite=None,
+    ):
+        """Sets a cookie. The parameters are the same as in the cookie `Morsel`
+        object in the Python standard library but it accepts unicode data, too.
+
+        A warning is raised if the size of the cookie header exceeds
+        :attr:`max_cookie_size`, but the header will still be set.
+
+        :param key: the key (name) of the cookie to be set.
+        :param value: the value of the cookie.
+        :param max_age: should be a number of seconds, or `None` (default) if
+                        the cookie should last only as long as the client's
+                        browser session.
+        :param expires: should be a `datetime` object or UNIX timestamp.
+        :param path: limits the cookie to a given path, per default it will
+                     span the whole domain.
+        :param domain: if you want to set a cross-domain cookie.  For example,
+                       ``domain=".example.com"`` will set a cookie that is
+                       readable by the domain ``www.example.com``,
+                       ``foo.example.com`` etc.  Otherwise, a cookie will only
+                       be readable by the domain that set it.
+        :param secure: If `True`, the cookie will only be available via HTTPS
+        :param httponly: disallow JavaScript to access the cookie.  This is an
+                         extension to the cookie standard and probably not
+                         supported by all browsers.
+        :param samesite: Limits the scope of the cookie such that it will only
+                         be attached to requests if those requests are
+                         "same-site".
+        """
+        self.headers.add(
+            "Set-Cookie",
+            dump_cookie(
+                key,
+                value=value,
+                max_age=max_age,
+                expires=expires,
+                path=path,
+                domain=domain,
+                secure=secure,
+                httponly=httponly,
+                charset=self.charset,
+                max_size=self.max_cookie_size,
+                samesite=samesite,
+            ),
+        )
+
+    def delete_cookie(self, key, path="/", domain=None):
+        """Delete a cookie.  Fails silently if key doesn't exist.
+
+        :param key: the key (name) of the cookie to be deleted.
+        :param path: if the cookie that should be deleted was limited to a
+                     path, the path has to be defined here.
+        :param domain: if the cookie that should be deleted was limited to a
+                       domain, that domain has to be defined here.
+        """
+        self.set_cookie(key, expires=0, max_age=0, path=path, domain=domain)
+
+    @property
+    def is_streamed(self):
+        """If the response is streamed (the response is not an iterable with
+        a length information) this property is `True`.  In this case streamed
+        means that there is no information about the number of iterations.
+        This is usually `True` if a generator is passed to the response object.
+
+        This is useful for checking before applying some sort of post
+        filtering that should not take place for streamed responses.
+        """
+        try:
+            len(self.response)
+        except (TypeError, AttributeError):
+            return True
+        return False
+
+    @property
+    def is_sequence(self):
+        """If the iterator is buffered, this property will be `True`.  A
+        response object will consider an iterator to be buffered if the
+        response attribute is a list or tuple.
+
+        .. versionadded:: 0.6
+        """
+        return isinstance(self.response, (tuple, list))
+
+    def close(self):
+        """Close the wrapped response if possible.  You can also use the object
+        in a with statement which will automatically close it.
+
+        .. versionadded:: 0.9
+           Can now be used in a with statement.
+        """
+        if hasattr(self.response, "close"):
+            self.response.close()
+        for func in self._on_close:
+            func()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, tb):
+        self.close()
+
+    def freeze(self):
+        """Call this method if you want to make your response object ready for
+        being pickled.  This buffers the generator if there is one.  It will
+        also set the `Content-Length` header to the length of the body.
+
+        .. versionchanged:: 0.6
+           The `Content-Length` header is now set.
+        """
+        # we explicitly set the length to a list of the *encoded* response
+        # iterator.  Even if the implicit sequence conversion is disabled.
+        self.response = list(self.iter_encoded())
+        self.headers["Content-Length"] = str(sum(map(len, self.response)))
+
+    def get_wsgi_headers(self, environ):
+        """This is automatically called right before the response is started
+        and returns headers modified for the given environment.  It returns a
+        copy of the headers from the response with some modifications applied
+        if necessary.
+
+        For example the location header (if present) is joined with the root
+        URL of the environment.  Also the content length is automatically set
+        to zero here for certain status codes.
+
+        .. versionchanged:: 0.6
+           Previously that function was called `fix_headers` and modified
+           the response object in place.  Also since 0.6, IRIs in location
+           and content-location headers are handled properly.
+
+           Also starting with 0.6, Werkzeug will attempt to set the content
+           length if it is able to figure it out on its own.  This is the
+           case if all the strings in the response iterable are already
+           encoded and the iterable is buffered.
+
+        :param environ: the WSGI environment of the request.
+        :return: returns a new :class:`~werkzeug.datastructures.Headers`
+                 object.
+        """
+        headers = Headers(self.headers)
+        location = None
+        content_location = None
+        content_length = None
+        status = self.status_code
+
+        # iterate over the headers to find all values in one go.  Because
+        # get_wsgi_headers is used each response that gives us a tiny
+        # speedup.
+        for key, value in headers:
+            ikey = key.lower()
+            if ikey == u"location":
+                location = value
+            elif ikey == u"content-location":
+                content_location = value
+            elif ikey == u"content-length":
+                content_length = value
+
+        # make sure the location header is an absolute URL
+        if location is not None:
+            old_location = location
+            if isinstance(location, text_type):
+                # Safe conversion is necessary here as we might redirect
+                # to a broken URI scheme (for instance itms-services).
+                location = iri_to_uri(location, safe_conversion=True)
+
+            if self.autocorrect_location_header:
+                current_url = get_current_url(environ, strip_querystring=True)
+                if isinstance(current_url, text_type):
+                    current_url = iri_to_uri(current_url)
+                location = url_join(current_url, location)
+            if location != old_location:
+                headers["Location"] = location
+
+        # make sure the content location is a URL
+        if content_location is not None and isinstance(content_location, text_type):
+            headers["Content-Location"] = iri_to_uri(content_location)
+
+        if 100 <= status < 200 or status == 204:
+            # Per section 3.3.2 of RFC 7230, "a server MUST NOT send a
+            # Content-Length header field in any response with a status
+            # code of 1xx (Informational) or 204 (No Content)."
+            headers.remove("Content-Length")
+        elif status == 304:
+            remove_entity_headers(headers)
+
+        # if we can determine the content length automatically, we
+        # should try to do that.  But only if this does not involve
+        # flattening the iterator or encoding of unicode strings in
+        # the response.  We however should not do that if we have a 304
+        # response.
+        if (
+            self.automatically_set_content_length
+            and self.is_sequence
+            and content_length is None
+            and status not in (204, 304)
+            and not (100 <= status < 200)
+        ):
+            try:
+                content_length = sum(len(to_bytes(x, "ascii")) for x in self.response)
+            except UnicodeError:
+                # aha, something non-bytestringy in there, too bad, we
+                # can't safely figure out the length of the response.
+                pass
+            else:
+                headers["Content-Length"] = str(content_length)
+
+        return headers
+
+    def get_app_iter(self, environ):
+        """Returns the application iterator for the given environ.  Depending
+        on the request method and the current status code the return value
+        might be an empty response rather than the one from the response.
+
+        If the request method is `HEAD` or the status code is in a range
+        where the HTTP specification requires an empty response, an empty
+        iterable is returned.
+
+        .. versionadded:: 0.6
+
+        :param environ: the WSGI environment of the request.
+        :return: a response iterable.
+        """
+        status = self.status_code
+        if (
+            environ["REQUEST_METHOD"] == "HEAD"
+            or 100 <= status < 200
+            or status in (204, 304)
+        ):
+            iterable = ()
+        elif self.direct_passthrough:
+            if __debug__:
+                _warn_if_string(self.response)
+            return self.response
+        else:
+            iterable = self.iter_encoded()
+        return ClosingIterator(iterable, self.close)
+
+    def get_wsgi_response(self, environ):
+        """Returns the final WSGI response as tuple.  The first item in
+        the tuple is the application iterator, the second the status and
+        the third the list of headers.  The response returned is created
+        specially for the given environment.  For example if the request
+        method in the WSGI environment is ``'HEAD'`` the response will
+        be empty and only the headers and status code will be present.
+
+        .. versionadded:: 0.6
+
+        :param environ: the WSGI environment of the request.
+        :return: an ``(app_iter, status, headers)`` tuple.
+        """
+        headers = self.get_wsgi_headers(environ)
+        app_iter = self.get_app_iter(environ)
+        return app_iter, self.status, headers.to_wsgi_list()
+
+    def __call__(self, environ, start_response):
+        """Process this response as WSGI application.
+
+        :param environ: the WSGI environment.
+        :param start_response: the response callable provided by the WSGI
+                               server.
+        :return: an application iterator
+        """
+        app_iter, status, headers = self.get_wsgi_response(environ)
+        start_response(status, headers)
+        return app_iter
diff --git a/python/werkzeug/wrappers/common_descriptors.py b/python/werkzeug/wrappers/common_descriptors.py
new file mode 100644
index 0000000..e4107ee
--- /dev/null
+++ b/python/werkzeug/wrappers/common_descriptors.py
@@ -0,0 +1,322 @@
+from datetime import datetime
+from datetime import timedelta
+
+from .._compat import string_types
+from ..datastructures import CallbackDict
+from ..http import dump_age
+from ..http import dump_header
+from ..http import dump_options_header
+from ..http import http_date
+from ..http import parse_age
+from ..http import parse_date
+from ..http import parse_options_header
+from ..http import parse_set_header
+from ..utils import cached_property
+from ..utils import environ_property
+from ..utils import get_content_type
+from ..utils import header_property
+from ..wsgi import get_content_length
+
+
+class CommonRequestDescriptorsMixin(object):
+    """A mixin for :class:`BaseRequest` subclasses.  Request objects that
+    mix this class in will automatically get descriptors for a couple of
+    HTTP headers with automatic type conversion.
+
+    .. versionadded:: 0.5
+    """
+
+    content_type = environ_property(
+        "CONTENT_TYPE",
+        doc="""The Content-Type entity-header field indicates the media
+        type of the entity-body sent to the recipient or, in the case of
+        the HEAD method, the media type that would have been sent had
+        the request been a GET.""",
+    )
+
+    @cached_property
+    def content_length(self):
+        """The Content-Length entity-header field indicates the size of the
+        entity-body in bytes or, in the case of the HEAD method, the size of
+        the entity-body that would have been sent had the request been a
+        GET.
+        """
+        return get_content_length(self.environ)
+
+    content_encoding = environ_property(
+        "HTTP_CONTENT_ENCODING",
+        doc="""The Content-Encoding entity-header field is used as a
+        modifier to the media-type. When present, its value indicates
+        what additional content codings have been applied to the
+        entity-body, and thus what decoding mechanisms must be applied
+        in order to obtain the media-type referenced by the Content-Type
+        header field.
+
+        .. versionadded:: 0.9""",
+    )
+    content_md5 = environ_property(
+        "HTTP_CONTENT_MD5",
+        doc="""The Content-MD5 entity-header field, as defined in
+        RFC 1864, is an MD5 digest of the entity-body for the purpose of
+        providing an end-to-end message integrity check (MIC) of the
+        entity-body. (Note: a MIC is good for detecting accidental
+        modification of the entity-body in transit, but is not proof
+        against malicious attacks.)
+
+        .. versionadded:: 0.9""",
+    )
+    referrer = environ_property(
+        "HTTP_REFERER",
+        doc="""The Referer[sic] request-header field allows the client
+        to specify, for the server's benefit, the address (URI) of the
+        resource from which the Request-URI was obtained (the
+        "referrer", although the header field is misspelled).""",
+    )
+    date = environ_property(
+        "HTTP_DATE",
+        None,
+        parse_date,
+        doc="""The Date general-header field represents the date and
+        time at which the message was originated, having the same
+        semantics as orig-date in RFC 822.""",
+    )
+    max_forwards = environ_property(
+        "HTTP_MAX_FORWARDS",
+        None,
+        int,
+        doc="""The Max-Forwards request-header field provides a
+        mechanism with the TRACE and OPTIONS methods to limit the number
+        of proxies or gateways that can forward the request to the next
+        inbound server.""",
+    )
+
+    def _parse_content_type(self):
+        if not hasattr(self, "_parsed_content_type"):
+            self._parsed_content_type = parse_options_header(
+                self.environ.get("CONTENT_TYPE", "")
+            )
+
+    @property
+    def mimetype(self):
+        """Like :attr:`content_type`, but without parameters (eg, without
+        charset, type etc.) and always lowercase.  For example if the content
+        type is ``text/HTML; charset=utf-8`` the mimetype would be
+        ``'text/html'``.
+        """
+        self._parse_content_type()
+        return self._parsed_content_type[0].lower()
+
+    @property
+    def mimetype_params(self):
+        """The mimetype parameters as dict.  For example if the content
+        type is ``text/html; charset=utf-8`` the params would be
+        ``{'charset': 'utf-8'}``.
+        """
+        self._parse_content_type()
+        return self._parsed_content_type[1]
+
+    @cached_property
+    def pragma(self):
+        """The Pragma general-header field is used to include
+        implementation-specific directives that might apply to any recipient
+        along the request/response chain.  All pragma directives specify
+        optional behavior from the viewpoint of the protocol; however, some
+        systems MAY require that behavior be consistent with the directives.
+        """
+        return parse_set_header(self.environ.get("HTTP_PRAGMA", ""))
+
+
+class CommonResponseDescriptorsMixin(object):
+    """A mixin for :class:`BaseResponse` subclasses.  Response objects that
+    mix this class in will automatically get descriptors for a couple of
+    HTTP headers with automatic type conversion.
+    """
+
+    @property
+    def mimetype(self):
+        """The mimetype (content type without charset etc.)"""
+        ct = self.headers.get("content-type")
+        if ct:
+            return ct.split(";")[0].strip()
+
+    @mimetype.setter
+    def mimetype(self, value):
+        self.headers["Content-Type"] = get_content_type(value, self.charset)
+
+    @property
+    def mimetype_params(self):
+        """The mimetype parameters as dict. For example if the
+        content type is ``text/html; charset=utf-8`` the params would be
+        ``{'charset': 'utf-8'}``.
+
+        .. versionadded:: 0.5
+        """
+
+        def on_update(d):
+            self.headers["Content-Type"] = dump_options_header(self.mimetype, d)
+
+        d = parse_options_header(self.headers.get("content-type", ""))[1]
+        return CallbackDict(d, on_update)
+
+    location = header_property(
+        "Location",
+        doc="""The Location response-header field is used to redirect
+        the recipient to a location other than the Request-URI for
+        completion of the request or identification of a new
+        resource.""",
+    )
+    age = header_property(
+        "Age",
+        None,
+        parse_age,
+        dump_age,
+        doc="""The Age response-header field conveys the sender's
+        estimate of the amount of time since the response (or its
+        revalidation) was generated at the origin server.
+
+        Age values are non-negative decimal integers, representing time
+        in seconds.""",
+    )
+    content_type = header_property(
+        "Content-Type",
+        doc="""The Content-Type entity-header field indicates the media
+        type of the entity-body sent to the recipient or, in the case of
+        the HEAD method, the media type that would have been sent had
+        the request been a GET.""",
+    )
+    content_length = header_property(
+        "Content-Length",
+        None,
+        int,
+        str,
+        doc="""The Content-Length entity-header field indicates the size
+        of the entity-body, in decimal number of OCTETs, sent to the
+        recipient or, in the case of the HEAD method, the size of the
+        entity-body that would have been sent had the request been a
+        GET.""",
+    )
+    content_location = header_property(
+        "Content-Location",
+        doc="""The Content-Location entity-header field MAY be used to
+        supply the resource location for the entity enclosed in the
+        message when that entity is accessible from a location separate
+        from the requested resource's URI.""",
+    )
+    content_encoding = header_property(
+        "Content-Encoding",
+        doc="""The Content-Encoding entity-header field is used as a
+        modifier to the media-type. When present, its value indicates
+        what additional content codings have been applied to the
+        entity-body, and thus what decoding mechanisms must be applied
+        in order to obtain the media-type referenced by the Content-Type
+        header field.""",
+    )
+    content_md5 = header_property(
+        "Content-MD5",
+        doc="""The Content-MD5 entity-header field, as defined in
+        RFC 1864, is an MD5 digest of the entity-body for the purpose of
+        providing an end-to-end message integrity check (MIC) of the
+        entity-body. (Note: a MIC is good for detecting accidental
+        modification of the entity-body in transit, but is not proof
+        against malicious attacks.)""",
+    )
+    date = header_property(
+        "Date",
+        None,
+        parse_date,
+        http_date,
+        doc="""The Date general-header field represents the date and
+        time at which the message was originated, having the same
+        semantics as orig-date in RFC 822.""",
+    )
+    expires = header_property(
+        "Expires",
+        None,
+        parse_date,
+        http_date,
+        doc="""The Expires entity-header field gives the date/time after
+        which the response is considered stale. A stale cache entry may
+        not normally be returned by a cache.""",
+    )
+    last_modified = header_property(
+        "Last-Modified",
+        None,
+        parse_date,
+        http_date,
+        doc="""The Last-Modified entity-header field indicates the date
+        and time at which the origin server believes the variant was
+        last modified.""",
+    )
+
+    @property
+    def retry_after(self):
+        """The Retry-After response-header field can be used with a
+        503 (Service Unavailable) response to indicate how long the
+        service is expected to be unavailable to the requesting client.
+
+        Time in seconds until expiration or date.
+        """
+        value = self.headers.get("retry-after")
+        if value is None:
+            return
+        elif value.isdigit():
+            return datetime.utcnow() + timedelta(seconds=int(value))
+        return parse_date(value)
+
+    @retry_after.setter
+    def retry_after(self, value):
+        if value is None:
+            if "retry-after" in self.headers:
+                del self.headers["retry-after"]
+            return
+        elif isinstance(value, datetime):
+            value = http_date(value)
+        else:
+            value = str(value)
+        self.headers["Retry-After"] = value
+
+    def _set_property(name, doc=None):  # noqa: B902
+        def fget(self):
+            def on_update(header_set):
+                if not header_set and name in self.headers:
+                    del self.headers[name]
+                elif header_set:
+                    self.headers[name] = header_set.to_header()
+
+            return parse_set_header(self.headers.get(name), on_update)
+
+        def fset(self, value):
+            if not value:
+                del self.headers[name]
+            elif isinstance(value, string_types):
+                self.headers[name] = value
+            else:
+                self.headers[name] = dump_header(value)
+
+        return property(fget, fset, doc=doc)
+
+    vary = _set_property(
+        "Vary",
+        doc="""The Vary field value indicates the set of request-header
+        fields that fully determines, while the response is fresh,
+        whether a cache is permitted to use the response to reply to a
+        subsequent request without revalidation.""",
+    )
+    content_language = _set_property(
+        "Content-Language",
+        doc="""The Content-Language entity-header field describes the
+        natural language(s) of the intended audience for the enclosed
+        entity. Note that this might not be equivalent to all the
+        languages used within the entity-body.""",
+    )
+    allow = _set_property(
+        "Allow",
+        doc="""The Allow entity-header field lists the set of methods
+        supported by the resource identified by the Request-URI. The
+        purpose of this field is strictly to inform the recipient of
+        valid methods associated with the resource. An Allow header
+        field MUST be present in a 405 (Method Not Allowed)
+        response.""",
+    )
+
+    del _set_property
diff --git a/python/werkzeug/wrappers/etag.py b/python/werkzeug/wrappers/etag.py
new file mode 100644
index 0000000..0733506
--- /dev/null
+++ b/python/werkzeug/wrappers/etag.py
@@ -0,0 +1,304 @@
+from .._compat import string_types
+from .._internal import _get_environ
+from ..datastructures import ContentRange
+from ..datastructures import RequestCacheControl
+from ..datastructures import ResponseCacheControl
+from ..http import generate_etag
+from ..http import http_date
+from ..http import is_resource_modified
+from ..http import parse_cache_control_header
+from ..http import parse_content_range_header
+from ..http import parse_date
+from ..http import parse_etags
+from ..http import parse_if_range_header
+from ..http import parse_range_header
+from ..http import quote_etag
+from ..http import unquote_etag
+from ..utils import cached_property
+from ..utils import header_property
+from ..wrappers.base_response import _clean_accept_ranges
+from ..wsgi import _RangeWrapper
+
+
+class ETagRequestMixin(object):
+    """Add entity tag and cache descriptors to a request object or object with
+    a WSGI environment available as :attr:`~BaseRequest.environ`.  This not
+    only provides access to etags but also to the cache control header.
+    """
+
+    @cached_property
+    def cache_control(self):
+        """A :class:`~werkzeug.datastructures.RequestCacheControl` object
+        for the incoming cache control headers.
+        """
+        cache_control = self.environ.get("HTTP_CACHE_CONTROL")
+        return parse_cache_control_header(cache_control, None, RequestCacheControl)
+
+    @cached_property
+    def if_match(self):
+        """An object containing all the etags in the `If-Match` header.
+
+        :rtype: :class:`~werkzeug.datastructures.ETags`
+        """
+        return parse_etags(self.environ.get("HTTP_IF_MATCH"))
+
+    @cached_property
+    def if_none_match(self):
+        """An object containing all the etags in the `If-None-Match` header.
+
+        :rtype: :class:`~werkzeug.datastructures.ETags`
+        """
+        return parse_etags(self.environ.get("HTTP_IF_NONE_MATCH"))
+
+    @cached_property
+    def if_modified_since(self):
+        """The parsed `If-Modified-Since` header as datetime object."""
+        return parse_date(self.environ.get("HTTP_IF_MODIFIED_SINCE"))
+
+    @cached_property
+    def if_unmodified_since(self):
+        """The parsed `If-Unmodified-Since` header as datetime object."""
+        return parse_date(self.environ.get("HTTP_IF_UNMODIFIED_SINCE"))
+
+    @cached_property
+    def if_range(self):
+        """The parsed `If-Range` header.
+
+        .. versionadded:: 0.7
+
+        :rtype: :class:`~werkzeug.datastructures.IfRange`
+        """
+        return parse_if_range_header(self.environ.get("HTTP_IF_RANGE"))
+
+    @cached_property
+    def range(self):
+        """The parsed `Range` header.
+
+        .. versionadded:: 0.7
+
+        :rtype: :class:`~werkzeug.datastructures.Range`
+        """
+        return parse_range_header(self.environ.get("HTTP_RANGE"))
+
+
+class ETagResponseMixin(object):
+    """Adds extra functionality to a response object for etag and cache
+    handling.  This mixin requires an object with at least a `headers`
+    object that implements a dict like interface similar to
+    :class:`~werkzeug.datastructures.Headers`.
+
+    If you want the :meth:`freeze` method to automatically add an etag, you
+    have to mixin this method before the response base class.  The default
+    response class does not do that.
+    """
+
+    @property
+    def cache_control(self):
+        """The Cache-Control general-header field is used to specify
+        directives that MUST be obeyed by all caching mechanisms along the
+        request/response chain.
+        """
+
+        def on_update(cache_control):
+            if not cache_control and "cache-control" in self.headers:
+                del self.headers["cache-control"]
+            elif cache_control:
+                self.headers["Cache-Control"] = cache_control.to_header()
+
+        return parse_cache_control_header(
+            self.headers.get("cache-control"), on_update, ResponseCacheControl
+        )
+
+    def _wrap_response(self, start, length):
+        """Wrap existing Response in case of Range Request context."""
+        if self.status_code == 206:
+            self.response = _RangeWrapper(self.response, start, length)
+
+    def _is_range_request_processable(self, environ):
+        """Return ``True`` if `Range` header is present and if underlying
+        resource is considered unchanged when compared with `If-Range` header.
+        """
+        return (
+            "HTTP_IF_RANGE" not in environ
+            or not is_resource_modified(
+                environ,
+                self.headers.get("etag"),
+                None,
+                self.headers.get("last-modified"),
+                ignore_if_range=False,
+            )
+        ) and "HTTP_RANGE" in environ
+
+    def _process_range_request(self, environ, complete_length=None, accept_ranges=None):
+        """Handle Range Request related headers (RFC7233).  If `Accept-Ranges`
+        header is valid, and Range Request is processable, we set the headers
+        as described by the RFC, and wrap the underlying response in a
+        RangeWrapper.
+
+        Returns ``True`` if Range Request can be fulfilled, ``False`` otherwise.
+
+        :raises: :class:`~werkzeug.exceptions.RequestedRangeNotSatisfiable`
+                 if `Range` header could not be parsed or satisfied.
+        """
+        from ..exceptions import RequestedRangeNotSatisfiable
+
+        if accept_ranges is None:
+            return False
+        self.headers["Accept-Ranges"] = accept_ranges
+        if not self._is_range_request_processable(environ) or complete_length is None:
+            return False
+        parsed_range = parse_range_header(environ.get("HTTP_RANGE"))
+        if parsed_range is None:
+            raise RequestedRangeNotSatisfiable(complete_length)
+        range_tuple = parsed_range.range_for_length(complete_length)
+        content_range_header = parsed_range.to_content_range_header(complete_length)
+        if range_tuple is None or content_range_header is None:
+            raise RequestedRangeNotSatisfiable(complete_length)
+        content_length = range_tuple[1] - range_tuple[0]
+        # Be sure not to send 206 response
+        # if requested range is the full content.
+        if content_length != complete_length:
+            self.headers["Content-Length"] = content_length
+            self.content_range = content_range_header
+            self.status_code = 206
+            self._wrap_response(range_tuple[0], content_length)
+            return True
+        return False
+
+    def make_conditional(
+        self, request_or_environ, accept_ranges=False, complete_length=None
+    ):
+        """Make the response conditional to the request.  This method works
+        best if an etag was defined for the response already.  The `add_etag`
+        method can be used to do that.  If called without etag just the date
+        header is set.
+
+        This does nothing if the request method in the request or environ is
+        anything but GET or HEAD.
+
+        For optimal performance when handling range requests, it's recommended
+        that your response data object implements `seekable`, `seek` and `tell`
+        methods as described by :py:class:`io.IOBase`.  Objects returned by
+        :meth:`~werkzeug.wsgi.wrap_file` automatically implement those methods.
+
+        It does not remove the body of the response because that's something
+        the :meth:`__call__` function does for us automatically.
+
+        Returns self so that you can do ``return resp.make_conditional(req)``
+        but modifies the object in-place.
+
+        :param request_or_environ: a request object or WSGI environment to be
+                                   used to make the response conditional
+                                   against.
+        :param accept_ranges: This parameter dictates the value of
+                              `Accept-Ranges` header. If ``False`` (default),
+                              the header is not set. If ``True``, it will be set
+                              to ``"bytes"``. If ``None``, it will be set to
+                              ``"none"``. If it's a string, it will use this
+                              value.
+        :param complete_length: Will be used only in valid Range Requests.
+                                It will set `Content-Range` complete length
+                                value and compute `Content-Length` real value.
+                                This parameter is mandatory for successful
+                                Range Requests completion.
+        :raises: :class:`~werkzeug.exceptions.RequestedRangeNotSatisfiable`
+                 if `Range` header could not be parsed or satisfied.
+        """
+        environ = _get_environ(request_or_environ)
+        if environ["REQUEST_METHOD"] in ("GET", "HEAD"):
+            # if the date is not in the headers, add it now.  We however
+            # will not override an already existing header.  Unfortunately
+            # this header will be overriden by many WSGI servers including
+            # wsgiref.
+            if "date" not in self.headers:
+                self.headers["Date"] = http_date()
+            accept_ranges = _clean_accept_ranges(accept_ranges)
+            is206 = self._process_range_request(environ, complete_length, accept_ranges)
+            if not is206 and not is_resource_modified(
+                environ,
+                self.headers.get("etag"),
+                None,
+                self.headers.get("last-modified"),
+            ):
+                if parse_etags(environ.get("HTTP_IF_MATCH")):
+                    self.status_code = 412
+                else:
+                    self.status_code = 304
+            if (
+                self.automatically_set_content_length
+                and "content-length" not in self.headers
+            ):
+                length = self.calculate_content_length()
+                if length is not None:
+                    self.headers["Content-Length"] = length
+        return self
+
+    def add_etag(self, overwrite=False, weak=False):
+        """Add an etag for the current response if there is none yet."""
+        if overwrite or "etag" not in self.headers:
+            self.set_etag(generate_etag(self.get_data()), weak)
+
+    def set_etag(self, etag, weak=False):
+        """Set the etag, and override the old one if there was one."""
+        self.headers["ETag"] = quote_etag(etag, weak)
+
+    def get_etag(self):
+        """Return a tuple in the form ``(etag, is_weak)``.  If there is no
+        ETag the return value is ``(None, None)``.
+        """
+        return unquote_etag(self.headers.get("ETag"))
+
+    def freeze(self, no_etag=False):
+        """Call this method if you want to make your response object ready for
+        pickeling.  This buffers the generator if there is one.  This also
+        sets the etag unless `no_etag` is set to `True`.
+        """
+        if not no_etag:
+            self.add_etag()
+        super(ETagResponseMixin, self).freeze()
+
+    accept_ranges = header_property(
+        "Accept-Ranges",
+        doc="""The `Accept-Ranges` header. Even though the name would
+        indicate that multiple values are supported, it must be one
+        string token only.
+
+        The values ``'bytes'`` and ``'none'`` are common.
+
+        .. versionadded:: 0.7""",
+    )
+
+    def _get_content_range(self):
+        def on_update(rng):
+            if not rng:
+                del self.headers["content-range"]
+            else:
+                self.headers["Content-Range"] = rng.to_header()
+
+        rv = parse_content_range_header(self.headers.get("content-range"), on_update)
+        # always provide a content range object to make the descriptor
+        # more user friendly.  It provides an unset() method that can be
+        # used to remove the header quickly.
+        if rv is None:
+            rv = ContentRange(None, None, None, on_update=on_update)
+        return rv
+
+    def _set_content_range(self, value):
+        if not value:
+            del self.headers["content-range"]
+        elif isinstance(value, string_types):
+            self.headers["Content-Range"] = value
+        else:
+            self.headers["Content-Range"] = value.to_header()
+
+    content_range = property(
+        _get_content_range,
+        _set_content_range,
+        doc="""The ``Content-Range`` header as
+        :class:`~werkzeug.datastructures.ContentRange` object. Even if
+        the header is not set it wil provide such an object for easier
+        manipulation.
+
+        .. versionadded:: 0.7""",
+    )
+    del _get_content_range, _set_content_range
diff --git a/python/werkzeug/wrappers/json.py b/python/werkzeug/wrappers/json.py
new file mode 100644
index 0000000..6d5dc33
--- /dev/null
+++ b/python/werkzeug/wrappers/json.py
@@ -0,0 +1,145 @@
+from __future__ import absolute_import
+
+import datetime
+import uuid
+
+from .._compat import text_type
+from ..exceptions import BadRequest
+from ..utils import detect_utf_encoding
+
+try:
+    import simplejson as _json
+except ImportError:
+    import json as _json
+
+
+class _JSONModule(object):
+    @staticmethod
+    def _default(o):
+        if isinstance(o, datetime.date):
+            return o.isoformat()
+
+        if isinstance(o, uuid.UUID):
+            return str(o)
+
+        if hasattr(o, "__html__"):
+            return text_type(o.__html__())
+
+        raise TypeError()
+
+    @classmethod
+    def dumps(cls, obj, **kw):
+        kw.setdefault("separators", (",", ":"))
+        kw.setdefault("default", cls._default)
+        kw.setdefault("sort_keys", True)
+        return _json.dumps(obj, **kw)
+
+    @staticmethod
+    def loads(s, **kw):
+        if isinstance(s, bytes):
+            # Needed for Python < 3.6
+            encoding = detect_utf_encoding(s)
+            s = s.decode(encoding)
+
+        return _json.loads(s, **kw)
+
+
+class JSONMixin(object):
+    """Mixin to parse :attr:`data` as JSON. Can be mixed in for both
+    :class:`~werkzeug.wrappers.Request` and
+    :class:`~werkzeug.wrappers.Response` classes.
+
+    If `simplejson`_ is installed it is preferred over Python's built-in
+    :mod:`json` module.
+
+    .. _simplejson: https://simplejson.readthedocs.io/en/latest/
+    """
+
+    #: A module or other object that has ``dumps`` and ``loads``
+    #: functions that match the API of the built-in :mod:`json` module.
+    json_module = _JSONModule
+
+    @property
+    def json(self):
+        """The parsed JSON data if :attr:`mimetype` indicates JSON
+        (:mimetype:`application/json`, see :meth:`is_json`).
+
+        Calls :meth:`get_json` with default arguments.
+        """
+        return self.get_json()
+
+    @property
+    def is_json(self):
+        """Check if the mimetype indicates JSON data, either
+        :mimetype:`application/json` or :mimetype:`application/*+json`.
+        """
+        mt = self.mimetype
+        return (
+            mt == "application/json"
+            or mt.startswith("application/")
+            and mt.endswith("+json")
+        )
+
+    def _get_data_for_json(self, cache):
+        try:
+            return self.get_data(cache=cache)
+        except TypeError:
+            # Response doesn't have cache param.
+            return self.get_data()
+
+    # Cached values for ``(silent=False, silent=True)``. Initialized
+    # with sentinel values.
+    _cached_json = (Ellipsis, Ellipsis)
+
+    def get_json(self, force=False, silent=False, cache=True):
+        """Parse :attr:`data` as JSON.
+
+        If the mimetype does not indicate JSON
+        (:mimetype:`application/json`, see :meth:`is_json`), this
+        returns ``None``.
+
+        If parsing fails, :meth:`on_json_loading_failed` is called and
+        its return value is used as the return value.
+
+        :param force: Ignore the mimetype and always try to parse JSON.
+        :param silent: Silence parsing errors and return ``None``
+            instead.
+        :param cache: Store the parsed JSON to return for subsequent
+            calls.
+        """
+        if cache and self._cached_json[silent] is not Ellipsis:
+            return self._cached_json[silent]
+
+        if not (force or self.is_json):
+            return None
+
+        data = self._get_data_for_json(cache=cache)
+
+        try:
+            rv = self.json_module.loads(data)
+        except ValueError as e:
+            if silent:
+                rv = None
+
+                if cache:
+                    normal_rv, _ = self._cached_json
+                    self._cached_json = (normal_rv, rv)
+            else:
+                rv = self.on_json_loading_failed(e)
+
+                if cache:
+                    _, silent_rv = self._cached_json
+                    self._cached_json = (rv, silent_rv)
+        else:
+            if cache:
+                self._cached_json = (rv, rv)
+
+        return rv
+
+    def on_json_loading_failed(self, e):
+        """Called if :meth:`get_json` parsing fails and isn't silenced.
+        If this method returns a value, it is used as the return value
+        for :meth:`get_json`. The default implementation raises
+        :exc:`~werkzeug.exceptions.BadRequest`.
+        """
+        raise BadRequest("Failed to decode JSON object: {0}".format(e))
diff --git a/python/werkzeug/wrappers/request.py b/python/werkzeug/wrappers/request.py
new file mode 100644
index 0000000..d1c71b6
--- /dev/null
+++ b/python/werkzeug/wrappers/request.py
@@ -0,0 +1,44 @@
+from .accept import AcceptMixin
+from .auth import AuthorizationMixin
+from .base_request import BaseRequest
+from .common_descriptors import CommonRequestDescriptorsMixin
+from .etag import ETagRequestMixin
+from .user_agent import UserAgentMixin
+
+
+class Request(
+    BaseRequest,
+    AcceptMixin,
+    ETagRequestMixin,
+    UserAgentMixin,
+    AuthorizationMixin,
+    CommonRequestDescriptorsMixin,
+):
+    """Full featured request object implementing the following mixins:
+
+    - :class:`AcceptMixin` for accept header parsing
+    - :class:`ETagRequestMixin` for etag and cache control handling
+    - :class:`UserAgentMixin` for user agent introspection
+    - :class:`AuthorizationMixin` for http auth handling
+    - :class:`CommonRequestDescriptorsMixin` for common headers
+    """
+
+
+class StreamOnlyMixin(object):
+    """If mixed in before the request object this will change the bahavior
+    of it to disable handling of form parsing.  This disables the
+    :attr:`files`, :attr:`form` attributes and will just provide a
+    :attr:`stream` attribute that however is always available.
+
+    .. versionadded:: 0.9
+    """
+
+    disable_data_descriptor = True
+    want_form_data_parsed = False
+
+
+class PlainRequest(StreamOnlyMixin, Request):
+    """A request object without special form parsing capabilities.
+
+    .. versionadded:: 0.9
+    """
diff --git a/python/werkzeug/wrappers/response.py b/python/werkzeug/wrappers/response.py
new file mode 100644
index 0000000..cd86cac
--- /dev/null
+++ b/python/werkzeug/wrappers/response.py
@@ -0,0 +1,78 @@
+from ..utils import cached_property
+from .auth import WWWAuthenticateMixin
+from .base_response import BaseResponse
+from .common_descriptors import CommonResponseDescriptorsMixin
+from .etag import ETagResponseMixin
+
+
+class ResponseStream(object):
+    """A file descriptor like object used by the :class:`ResponseStreamMixin` to
+    represent the body of the stream.  It directly pushes into the response
+    iterable of the response object.
+    """
+
+    mode = "wb+"
+
+    def __init__(self, response):
+        self.response = response
+        self.closed = False
+
+    def write(self, value):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        self.response._ensure_sequence(mutable=True)
+        self.response.response.append(value)
+        self.response.headers.pop("Content-Length", None)
+        return len(value)
+
+    def writelines(self, seq):
+        for item in seq:
+            self.write(item)
+
+    def close(self):
+        self.closed = True
+
+    def flush(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+
+    def isatty(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+        return False
+
+    def tell(self):
+        self.response._ensure_sequence()
+        return sum(map(len, self.response.response))
+
+    @property
+    def encoding(self):
+        return self.response.charset
+
+
+class ResponseStreamMixin(object):
+    """Mixin for :class:`BaseRequest` subclasses.  Classes that inherit from
+    this mixin will automatically get a :attr:`stream` property that provides
+    a write-only interface to the response iterable.
+    """
+
+    @cached_property
+    def stream(self):
+        """The response iterable as write-only stream."""
+        return ResponseStream(self)
+
+
+class Response(
+    BaseResponse,
+    ETagResponseMixin,
+    ResponseStreamMixin,
+    CommonResponseDescriptorsMixin,
+    WWWAuthenticateMixin,
+):
+    """Full featured response object implementing the following mixins:
+
+    - :class:`ETagResponseMixin` for etag and cache control handling
+    - :class:`ResponseStreamMixin` to add support for the `stream` property
+    - :class:`CommonResponseDescriptorsMixin` for various HTTP descriptors
+    - :class:`WWWAuthenticateMixin` for HTTP authentication support
+    """
diff --git a/python/werkzeug/wrappers/user_agent.py b/python/werkzeug/wrappers/user_agent.py
new file mode 100644
index 0000000..72588dd
--- /dev/null
+++ b/python/werkzeug/wrappers/user_agent.py
@@ -0,0 +1,15 @@
+from ..utils import cached_property
+
+
+class UserAgentMixin(object):
+    """Adds a `user_agent` attribute to the request object which
+    contains the parsed user agent of the browser that triggered the
+    request as a :class:`~werkzeug.useragents.UserAgent` object.
+    """
+
+    @cached_property
+    def user_agent(self):
+        """The current user agent."""
+        from ..useragents import UserAgent
+
+        return UserAgent(self.environ)
diff --git a/python/werkzeug/wsgi.py b/python/werkzeug/wsgi.py
new file mode 100644
index 0000000..f069f2d
--- /dev/null
+++ b/python/werkzeug/wsgi.py
@@ -0,0 +1,1067 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.wsgi
+    ~~~~~~~~~~~~~
+
+    This module implements WSGI related helpers.
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import io
+import re
+import warnings
+from functools import partial
+from functools import update_wrapper
+from itertools import chain
+
+from ._compat import BytesIO
+from ._compat import implements_iterator
+from ._compat import make_literal_wrapper
+from ._compat import string_types
+from ._compat import text_type
+from ._compat import to_bytes
+from ._compat import to_unicode
+from ._compat import try_coerce_native
+from ._compat import wsgi_get_bytes
+from ._internal import _encode_idna
+from .urls import uri_to_iri
+from .urls import url_join
+from .urls import url_parse
+from .urls import url_quote
+
+
+def responder(f):
+    """Marks a function as responder.  Decorate a function with it and it
+    will automatically call the return value as WSGI application.
+
+    Example::
+
+        @responder
+        def application(environ, start_response):
+            return Response('Hello World!')
+    """
+    return update_wrapper(lambda *a: f(*a)(*a[-2:]), f)
+
+
+def get_current_url(
+    environ,
+    root_only=False,
+    strip_querystring=False,
+    host_only=False,
+    trusted_hosts=None,
+):
+    """A handy helper function that recreates the full URL as IRI for the
+    current request or parts of it.  Here's an example:
+
+    >>> from werkzeug.test import create_environ
+    >>> env = create_environ("/?param=foo", "http://localhost/script")
+    >>> get_current_url(env)
+    'http://localhost/script/?param=foo'
+    >>> get_current_url(env, root_only=True)
+    'http://localhost/script/'
+    >>> get_current_url(env, host_only=True)
+    'http://localhost/'
+    >>> get_current_url(env, strip_querystring=True)
+    'http://localhost/script/'
+
+    This optionally it verifies that the host is in a list of trusted hosts.
+    If the host is not in there it will raise a
+    :exc:`~werkzeug.exceptions.SecurityError`.
+
+    Note that the string returned might contain unicode characters as the
+    representation is an IRI not an URI.  If you need an ASCII only
+    representation you can use the :func:`~werkzeug.urls.iri_to_uri`
+    function:
+
+    >>> from werkzeug.urls import iri_to_uri
+    >>> iri_to_uri(get_current_url(env))
+    'http://localhost/script/?param=foo'
+
+    :param environ: the WSGI environment to get the current URL from.
+    :param root_only: set `True` if you only want the root URL.
+    :param strip_querystring: set to `True` if you don't want the querystring.
+    :param host_only: set to `True` if the host URL should be returned.
+    :param trusted_hosts: a list of trusted hosts, see :func:`host_is_trusted`
+                          for more information.
+    """
+    tmp = [environ["wsgi.url_scheme"], "://", get_host(environ, trusted_hosts)]
+    cat = tmp.append
+    if host_only:
+        return uri_to_iri("".join(tmp) + "/")
+    cat(url_quote(wsgi_get_bytes(environ.get("SCRIPT_NAME", ""))).rstrip("/"))
+    cat("/")
+    if not root_only:
+        cat(url_quote(wsgi_get_bytes(environ.get("PATH_INFO", "")).lstrip(b"/")))
+        if not strip_querystring:
+            qs = get_query_string(environ)
+            if qs:
+                cat("?" + qs)
+    return uri_to_iri("".join(tmp))
+
+
+def host_is_trusted(hostname, trusted_list):
+    """Checks if a host is trusted against a list.  This also takes care
+    of port normalization.
+
+    .. versionadded:: 0.9
+
+    :param hostname: the hostname to check
+    :param trusted_list: a list of hostnames to check against.  If a
+                         hostname starts with a dot it will match against
+                         all subdomains as well.
+    """
+    if not hostname:
+        return False
+
+    if isinstance(trusted_list, string_types):
+        trusted_list = [trusted_list]
+
+    def _normalize(hostname):
+        if ":" in hostname:
+            hostname = hostname.rsplit(":", 1)[0]
+        return _encode_idna(hostname)
+
+    try:
+        hostname = _normalize(hostname)
+    except UnicodeError:
+        return False
+    for ref in trusted_list:
+        if ref.startswith("."):
+            ref = ref[1:]
+            suffix_match = True
+        else:
+            suffix_match = False
+        try:
+            ref = _normalize(ref)
+        except UnicodeError:
+            return False
+        if ref == hostname:
+            return True
+        if suffix_match and hostname.endswith(b"." + ref):
+            return True
+    return False
+
+
+def get_host(environ, trusted_hosts=None):
+    """Return the host for the given WSGI environment. This first checks
+    the ``Host`` header. If it's not present, then ``SERVER_NAME`` and
+    ``SERVER_PORT`` are used. The host will only contain the port if it
+    is different than the standard port for the protocol.
+
+    Optionally, verify that the host is trusted using
+    :func:`host_is_trusted` and raise a
+    :exc:`~werkzeug.exceptions.SecurityError` if it is not.
+
+    :param environ: The WSGI environment to get the host from.
+    :param trusted_hosts: A list of trusted hosts.
+    :return: Host, with port if necessary.
+    :raise ~werkzeug.exceptions.SecurityError: If the host is not
+        trusted.
+    """
+    if "HTTP_HOST" in environ:
+        rv = environ["HTTP_HOST"]
+        if environ["wsgi.url_scheme"] == "http" and rv.endswith(":80"):
+            rv = rv[:-3]
+        elif environ["wsgi.url_scheme"] == "https" and rv.endswith(":443"):
+            rv = rv[:-4]
+    else:
+        rv = environ["SERVER_NAME"]
+        if (environ["wsgi.url_scheme"], environ["SERVER_PORT"]) not in (
+            ("https", "443"),
+            ("http", "80"),
+        ):
+            rv += ":" + environ["SERVER_PORT"]
+    if trusted_hosts is not None:
+        if not host_is_trusted(rv, trusted_hosts):
+            from .exceptions import SecurityError
+
+            raise SecurityError('Host "%s" is not trusted' % rv)
+    return rv
+
+
+def get_content_length(environ):
+    """Returns the content length from the WSGI environment as
+    integer. If it's not available or chunked transfer encoding is used,
+    ``None`` is returned.
+
+    .. versionadded:: 0.9
+
+    :param environ: the WSGI environ to fetch the content length from.
+    """
+    if environ.get("HTTP_TRANSFER_ENCODING", "") == "chunked":
+        return None
+
+    content_length = environ.get("CONTENT_LENGTH")
+    if content_length is not None:
+        try:
+            return max(0, int(content_length))
+        except (ValueError, TypeError):
+            pass
+
+
+def get_input_stream(environ, safe_fallback=True):
+    """Returns the input stream from the WSGI environment and wraps it
+    in the most sensible way possible. The stream returned is not the
+    raw WSGI stream in most cases but one that is safe to read from
+    without taking into account the content length.
+
+    If content length is not set, the stream will be empty for safety reasons.
+    If the WSGI server supports chunked or infinite streams, it should set
+    the ``wsgi.input_terminated`` value in the WSGI environ to indicate that.
+
+    .. versionadded:: 0.9
+
+    :param environ: the WSGI environ to fetch the stream from.
+    :param safe_fallback: use an empty stream as a safe fallback when the
+        content length is not set. Disabling this allows infinite streams,
+        which can be a denial-of-service risk.
+    """
+    stream = environ["wsgi.input"]
+    content_length = get_content_length(environ)
+
+    # A wsgi extension that tells us if the input is terminated.  In
+    # that case we return the stream unchanged as we know we can safely
+    # read it until the end.
+    if environ.get("wsgi.input_terminated"):
+        return stream
+
+    # If the request doesn't specify a content length, returning the stream is
+    # potentially dangerous because it could be infinite, malicious or not. If
+    # safe_fallback is true, return an empty stream instead for safety.
+    if content_length is None:
+        return BytesIO() if safe_fallback else stream
+
+    # Otherwise limit the stream to the content length
+    return LimitedStream(stream, content_length)
+
+
+def get_query_string(environ):
+    """Returns the `QUERY_STRING` from the WSGI environment.  This also takes
+    care about the WSGI decoding dance on Python 3 environments as a
+    native string.  The string returned will be restricted to ASCII
+    characters.
+
+    .. versionadded:: 0.9
+
+    :param environ: the WSGI environment object to get the query string from.
+    """
+    qs = wsgi_get_bytes(environ.get("QUERY_STRING", ""))
+    # QUERY_STRING really should be ascii safe but some browsers
+    # will send us some unicode stuff (I am looking at you IE).
+    # In that case we want to urllib quote it badly.
+    return try_coerce_native(url_quote(qs, safe=":&%=+$!*'(),"))
+
+
+def get_path_info(environ, charset="utf-8", errors="replace"):
+    """Returns the `PATH_INFO` from the WSGI environment and properly
+    decodes it.  This also takes care about the WSGI decoding dance
+    on Python 3 environments.  if the `charset` is set to `None` a
+    bytestring is returned.
+
+    .. versionadded:: 0.9
+
+    :param environ: the WSGI environment object to get the path from.
+    :param charset: the charset for the path info, or `None` if no
+                    decoding should be performed.
+    :param errors: the decoding error handling.
+    """
+    path = wsgi_get_bytes(environ.get("PATH_INFO", ""))
+    return to_unicode(path, charset, errors, allow_none_charset=True)
+
+
+def get_script_name(environ, charset="utf-8", errors="replace"):
+    """Returns the `SCRIPT_NAME` from the WSGI environment and properly
+    decodes it.  This also takes care about the WSGI decoding dance
+    on Python 3 environments.  if the `charset` is set to `None` a
+    bytestring is returned.
+
+    .. versionadded:: 0.9
+
+    :param environ: the WSGI environment object to get the path from.
+    :param charset: the charset for the path, or `None` if no
+                    decoding should be performed.
+    :param errors: the decoding error handling.
+    """
+    path = wsgi_get_bytes(environ.get("SCRIPT_NAME", ""))
+    return to_unicode(path, charset, errors, allow_none_charset=True)
+
+
+def pop_path_info(environ, charset="utf-8", errors="replace"):
+    """Removes and returns the next segment of `PATH_INFO`, pushing it onto
+    `SCRIPT_NAME`.  Returns `None` if there is nothing left on `PATH_INFO`.
+
+    If the `charset` is set to `None` a bytestring is returned.
+
+    If there are empty segments (``'/foo//bar``) these are ignored but
+    properly pushed to the `SCRIPT_NAME`:
+
+    >>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
+    >>> pop_path_info(env)
+    'a'
+    >>> env['SCRIPT_NAME']
+    '/foo/a'
+    >>> pop_path_info(env)
+    'b'
+    >>> env['SCRIPT_NAME']
+    '/foo/a/b'
+
+    .. versionadded:: 0.5
+
+    .. versionchanged:: 0.9
+       The path is now decoded and a charset and encoding
+       parameter can be provided.
+
+    :param environ: the WSGI environment that is modified.
+    """
+    path = environ.get("PATH_INFO")
+    if not path:
+        return None
+
+    script_name = environ.get("SCRIPT_NAME", "")
+
+    # shift multiple leading slashes over
+    old_path = path
+    path = path.lstrip("/")
+    if path != old_path:
+        script_name += "/" * (len(old_path) - len(path))
+
+    if "/" not in path:
+        environ["PATH_INFO"] = ""
+        environ["SCRIPT_NAME"] = script_name + path
+        rv = wsgi_get_bytes(path)
+    else:
+        segment, path = path.split("/", 1)
+        environ["PATH_INFO"] = "/" + path
+        environ["SCRIPT_NAME"] = script_name + segment
+        rv = wsgi_get_bytes(segment)
+
+    return to_unicode(rv, charset, errors, allow_none_charset=True)
+
+
+def peek_path_info(environ, charset="utf-8", errors="replace"):
+    """Returns the next segment on the `PATH_INFO` or `None` if there
+    is none.  Works like :func:`pop_path_info` without modifying the
+    environment:
+
+    >>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
+    >>> peek_path_info(env)
+    'a'
+    >>> peek_path_info(env)
+    'a'
+
+    If the `charset` is set to `None` a bytestring is returned.
+
+    .. versionadded:: 0.5
+
+    .. versionchanged:: 0.9
+       The path is now decoded and a charset and encoding
+       parameter can be provided.
+
+    :param environ: the WSGI environment that is checked.
+    """
+    segments = environ.get("PATH_INFO", "").lstrip("/").split("/", 1)
+    if segments:
+        return to_unicode(
+            wsgi_get_bytes(segments[0]), charset, errors, allow_none_charset=True
+        )
+
+
+def extract_path_info(
+    environ_or_baseurl,
+    path_or_url,
+    charset="utf-8",
+    errors="werkzeug.url_quote",
+    collapse_http_schemes=True,
+):
+    """Extracts the path info from the given URL (or WSGI environment) and
+    path.  The path info returned is a unicode string, not a bytestring
+    suitable for a WSGI environment.  The URLs might also be IRIs.
+
+    If the path info could not be determined, `None` is returned.
+
+    Some examples:
+
+    >>> extract_path_info('http://example.com/app', '/app/hello')
+    u'/hello'
+    >>> extract_path_info('http://example.com/app',
+    ...                   'https://example.com/app/hello')
+    u'/hello'
+    >>> extract_path_info('http://example.com/app',
+    ...                   'https://example.com/app/hello',
+    ...                   collapse_http_schemes=False) is None
+    True
+
+    Instead of providing a base URL you can also pass a WSGI environment.
+
+    :param environ_or_baseurl: a WSGI environment dict, a base URL or
+                               base IRI.  This is the root of the
+                               application.
+    :param path_or_url: an absolute path from the server root, a
+                        relative path (in which case it's the path info)
+                        or a full URL.  Also accepts IRIs and unicode
+                        parameters.
+    :param charset: the charset for byte data in URLs
+    :param errors: the error handling on decode
+    :param collapse_http_schemes: if set to `False` the algorithm does
+                                  not assume that http and https on the
+                                  same server point to the same
+                                  resource.
+
+    .. versionchanged:: 0.15
+        The ``errors`` parameter defaults to leaving invalid bytes
+        quoted instead of replacing them.
+
+    .. versionadded:: 0.6
+    """
+
+    def _normalize_netloc(scheme, netloc):
+        parts = netloc.split(u"@", 1)[-1].split(u":", 1)
+        if len(parts) == 2:
+            netloc, port = parts
+            if (scheme == u"http" and port == u"80") or (
+                scheme == u"https" and port == u"443"
+            ):
+                port = None
+        else:
+            netloc = parts[0]
+            port = None
+        if port is not None:
+            netloc += u":" + port
+        return netloc
+
+    # make sure whatever we are working on is a IRI and parse it
+    path = uri_to_iri(path_or_url, charset, errors)
+    if isinstance(environ_or_baseurl, dict):
+        environ_or_baseurl = get_current_url(environ_or_baseurl, root_only=True)
+    base_iri = uri_to_iri(environ_or_baseurl, charset, errors)
+    base_scheme, base_netloc, base_path = url_parse(base_iri)[:3]
+    cur_scheme, cur_netloc, cur_path, = url_parse(url_join(base_iri, path))[:3]
+
+    # normalize the network location
+    base_netloc = _normalize_netloc(base_scheme, base_netloc)
+    cur_netloc = _normalize_netloc(cur_scheme, cur_netloc)
+
+    # is that IRI even on a known HTTP scheme?
+    if collapse_http_schemes:
+        for scheme in base_scheme, cur_scheme:
+            if scheme not in (u"http", u"https"):
+                return None
+    else:
+        if not (base_scheme in (u"http", u"https") and base_scheme == cur_scheme):
+            return None
+
+    # are the netlocs compatible?
+    if base_netloc != cur_netloc:
+        return None
+
+    # are we below the application path?
+    base_path = base_path.rstrip(u"/")
+    if not cur_path.startswith(base_path):
+        return None
+
+    return u"/" + cur_path[len(base_path) :].lstrip(u"/")
+
+
+@implements_iterator
+class ClosingIterator(object):
+    """The WSGI specification requires that all middlewares and gateways
+    respect the `close` callback of the iterable returned by the application.
+    Because it is useful to add another close action to a returned iterable
+    and adding a custom iterable is a boring task this class can be used for
+    that::
+
+        return ClosingIterator(app(environ, start_response), [cleanup_session,
+                                                              cleanup_locals])
+
+    If there is just one close function it can be passed instead of the list.
+
+    A closing iterator is not needed if the application uses response objects
+    and finishes the processing if the response is started::
+
+        try:
+            return response(environ, start_response)
+        finally:
+            cleanup_session()
+            cleanup_locals()
+    """
+
+    def __init__(self, iterable, callbacks=None):
+        iterator = iter(iterable)
+        self._next = partial(next, iterator)
+        if callbacks is None:
+            callbacks = []
+        elif callable(callbacks):
+            callbacks = [callbacks]
+        else:
+            callbacks = list(callbacks)
+        iterable_close = getattr(iterable, "close", None)
+        if iterable_close:
+            callbacks.insert(0, iterable_close)
+        self._callbacks = callbacks
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        return self._next()
+
+    def close(self):
+        for callback in self._callbacks:
+            callback()
+
+
+def wrap_file(environ, file, buffer_size=8192):
+    """Wraps a file.  This uses the WSGI server's file wrapper if available
+    or otherwise the generic :class:`FileWrapper`.
+
+    .. versionadded:: 0.5
+
+    If the file wrapper from the WSGI server is used it's important to not
+    iterate over it from inside the application but to pass it through
+    unchanged.  If you want to pass out a file wrapper inside a response
+    object you have to set :attr:`~BaseResponse.direct_passthrough` to `True`.
+
+    More information about file wrappers are available in :pep:`333`.
+
+    :param file: a :class:`file`-like object with a :meth:`~file.read` method.
+    :param buffer_size: number of bytes for one iteration.
+    """
+    return environ.get("wsgi.file_wrapper", FileWrapper)(file, buffer_size)
+
+
+@implements_iterator
+class FileWrapper(object):
+    """This class can be used to convert a :class:`file`-like object into
+    an iterable.  It yields `buffer_size` blocks until the file is fully
+    read.
+
+    You should not use this class directly but rather use the
+    :func:`wrap_file` function that uses the WSGI server's file wrapper
+    support if it's available.
+
+    .. versionadded:: 0.5
+
+    If you're using this object together with a :class:`BaseResponse` you have
+    to use the `direct_passthrough` mode.
+
+    :param file: a :class:`file`-like object with a :meth:`~file.read` method.
+    :param buffer_size: number of bytes for one iteration.
+    """
+
+    def __init__(self, file, buffer_size=8192):
+        self.file = file
+        self.buffer_size = buffer_size
+
+    def close(self):
+        if hasattr(self.file, "close"):
+            self.file.close()
+
+    def seekable(self):
+        if hasattr(self.file, "seekable"):
+            return self.file.seekable()
+        if hasattr(self.file, "seek"):
+            return True
+        return False
+
+    def seek(self, *args):
+        if hasattr(self.file, "seek"):
+            self.file.seek(*args)
+
+    def tell(self):
+        if hasattr(self.file, "tell"):
+            return self.file.tell()
+        return None
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        data = self.file.read(self.buffer_size)
+        if data:
+            return data
+        raise StopIteration()
+
+
+@implements_iterator
+class _RangeWrapper(object):
+    # private for now, but should we make it public in the future ?
+
+    """This class can be used to convert an iterable object into
+    an iterable that will only yield a piece of the underlying content.
+    It yields blocks until the underlying stream range is fully read.
+    The yielded blocks will have a size that can't exceed the original
+    iterator defined block size, but that can be smaller.
+
+    If you're using this object together with a :class:`BaseResponse` you have
+    to use the `direct_passthrough` mode.
+
+    :param iterable: an iterable object with a :meth:`__next__` method.
+    :param start_byte: byte from which read will start.
+    :param byte_range: how many bytes to read.
+    """
+
+    def __init__(self, iterable, start_byte=0, byte_range=None):
+        self.iterable = iter(iterable)
+        self.byte_range = byte_range
+        self.start_byte = start_byte
+        self.end_byte = None
+        if byte_range is not None:
+            self.end_byte = self.start_byte + self.byte_range
+        self.read_length = 0
+        self.seekable = hasattr(iterable, "seekable") and iterable.seekable()
+        self.end_reached = False
+
+    def __iter__(self):
+        return self
+
+    def _next_chunk(self):
+        try:
+            chunk = next(self.iterable)
+            self.read_length += len(chunk)
+            return chunk
+        except StopIteration:
+            self.end_reached = True
+            raise
+
+    def _first_iteration(self):
+        chunk = None
+        if self.seekable:
+            self.iterable.seek(self.start_byte)
+            self.read_length = self.iterable.tell()
+            contextual_read_length = self.read_length
+        else:
+            while self.read_length <= self.start_byte:
+                chunk = self._next_chunk()
+            if chunk is not None:
+                chunk = chunk[self.start_byte - self.read_length :]
+            contextual_read_length = self.start_byte
+        return chunk, contextual_read_length
+
+    def _next(self):
+        if self.end_reached:
+            raise StopIteration()
+        chunk = None
+        contextual_read_length = self.read_length
+        if self.read_length == 0:
+            chunk, contextual_read_length = self._first_iteration()
+        if chunk is None:
+            chunk = self._next_chunk()
+        if self.end_byte is not None and self.read_length >= self.end_byte:
+            self.end_reached = True
+            return chunk[: self.end_byte - contextual_read_length]
+        return chunk
+
+    def __next__(self):
+        chunk = self._next()
+        if chunk:
+            return chunk
+        self.end_reached = True
+        raise StopIteration()
+
+    def close(self):
+        if hasattr(self.iterable, "close"):
+            self.iterable.close()
+
+
+def _make_chunk_iter(stream, limit, buffer_size):
+    """Helper for the line and chunk iter functions."""
+    if isinstance(stream, (bytes, bytearray, text_type)):
+        raise TypeError(
+            "Passed a string or byte object instead of true iterator or stream."
+        )
+    if not hasattr(stream, "read"):
+        for item in stream:
+            if item:
+                yield item
+        return
+    if not isinstance(stream, LimitedStream) and limit is not None:
+        stream = LimitedStream(stream, limit)
+    _read = stream.read
+    while 1:
+        item = _read(buffer_size)
+        if not item:
+            break
+        yield item
+
+
+def make_line_iter(stream, limit=None, buffer_size=10 * 1024, cap_at_buffer=False):
+    """Safely iterates line-based over an input stream.  If the input stream
+    is not a :class:`LimitedStream` the `limit` parameter is mandatory.
+
+    This uses the stream's :meth:`~file.read` method internally as opposite
+    to the :meth:`~file.readline` method that is unsafe and can only be used
+    in violation of the WSGI specification.  The same problem applies to the
+    `__iter__` function of the input stream which calls :meth:`~file.readline`
+    without arguments.
+
+    If you need line-by-line processing it's strongly recommended to iterate
+    over the input stream using this helper function.
+
+    .. versionchanged:: 0.8
+       This function now ensures that the limit was reached.
+
+    .. versionadded:: 0.9
+       added support for iterators as input stream.
+
+    .. versionadded:: 0.11.10
+       added support for the `cap_at_buffer` parameter.
+
+    :param stream: the stream or iterate to iterate over.
+    :param limit: the limit in bytes for the stream.  (Usually
+                  content length.  Not necessary if the `stream`
+                  is a :class:`LimitedStream`.
+    :param buffer_size: The optional buffer size.
+    :param cap_at_buffer: if this is set chunks are split if they are longer
+                          than the buffer size.  Internally this is implemented
+                          that the buffer size might be exhausted by a factor
+                          of two however.
+    """
+    _iter = _make_chunk_iter(stream, limit, buffer_size)
+
+    first_item = next(_iter, "")
+    if not first_item:
+        return
+
+    s = make_literal_wrapper(first_item)
+    empty = s("")
+    cr = s("\r")
+    lf = s("\n")
+    crlf = s("\r\n")
+
+    _iter = chain((first_item,), _iter)
+
+    def _iter_basic_lines():
+        _join = empty.join
+        buffer = []
+        while 1:
+            new_data = next(_iter, "")
+            if not new_data:
+                break
+            new_buf = []
+            buf_size = 0
+            for item in chain(buffer, new_data.splitlines(True)):
+                new_buf.append(item)
+                buf_size += len(item)
+                if item and item[-1:] in crlf:
+                    yield _join(new_buf)
+                    new_buf = []
+                elif cap_at_buffer and buf_size >= buffer_size:
+                    rv = _join(new_buf)
+                    while len(rv) >= buffer_size:
+                        yield rv[:buffer_size]
+                        rv = rv[buffer_size:]
+                    new_buf = [rv]
+            buffer = new_buf
+        if buffer:
+            yield _join(buffer)
+
+    # This hackery is necessary to merge 'foo\r' and '\n' into one item
+    # of 'foo\r\n' if we were unlucky and we hit a chunk boundary.
+    previous = empty
+    for item in _iter_basic_lines():
+        if item == lf and previous[-1:] == cr:
+            previous += item
+            item = empty
+        if previous:
+            yield previous
+        previous = item
+    if previous:
+        yield previous
+
+
+def make_chunk_iter(
+    stream, separator, limit=None, buffer_size=10 * 1024, cap_at_buffer=False
+):
+    """Works like :func:`make_line_iter` but accepts a separator
+    which divides chunks.  If you want newline based processing
+    you should use :func:`make_line_iter` instead as it
+    supports arbitrary newline markers.
+
+    .. versionadded:: 0.8
+
+    .. versionadded:: 0.9
+       added support for iterators as input stream.
+
+    .. versionadded:: 0.11.10
+       added support for the `cap_at_buffer` parameter.
+
+    :param stream: the stream or iterate to iterate over.
+    :param separator: the separator that divides chunks.
+    :param limit: the limit in bytes for the stream.  (Usually
+                  content length.  Not necessary if the `stream`
+                  is otherwise already limited).
+    :param buffer_size: The optional buffer size.
+    :param cap_at_buffer: if this is set chunks are split if they are longer
+                          than the buffer size.  Internally this is implemented
+                          that the buffer size might be exhausted by a factor
+                          of two however.
+    """
+    _iter = _make_chunk_iter(stream, limit, buffer_size)
+
+    first_item = next(_iter, "")
+    if not first_item:
+        return
+
+    _iter = chain((first_item,), _iter)
+    if isinstance(first_item, text_type):
+        separator = to_unicode(separator)
+        _split = re.compile(r"(%s)" % re.escape(separator)).split
+        _join = u"".join
+    else:
+        separator = to_bytes(separator)
+        _split = re.compile(b"(" + re.escape(separator) + b")").split
+        _join = b"".join
+
+    buffer = []
+    while 1:
+        new_data = next(_iter, "")
+        if not new_data:
+            break
+        chunks = _split(new_data)
+        new_buf = []
+        buf_size = 0
+        for item in chain(buffer, chunks):
+            if item == separator:
+                yield _join(new_buf)
+                new_buf = []
+                buf_size = 0
+            else:
+                buf_size += len(item)
+                new_buf.append(item)
+
+                if cap_at_buffer and buf_size >= buffer_size:
+                    rv = _join(new_buf)
+                    while len(rv) >= buffer_size:
+                        yield rv[:buffer_size]
+                        rv = rv[buffer_size:]
+                    new_buf = [rv]
+                    buf_size = len(rv)
+
+        buffer = new_buf
+    if buffer:
+        yield _join(buffer)
+
+
+@implements_iterator
+class LimitedStream(io.IOBase):
+    """Wraps a stream so that it doesn't read more than n bytes.  If the
+    stream is exhausted and the caller tries to get more bytes from it
+    :func:`on_exhausted` is called which by default returns an empty
+    string.  The return value of that function is forwarded
+    to the reader function.  So if it returns an empty string
+    :meth:`read` will return an empty string as well.
+
+    The limit however must never be higher than what the stream can
+    output.  Otherwise :meth:`readlines` will try to read past the
+    limit.
+
+    .. admonition:: Note on WSGI compliance
+
+       calls to :meth:`readline` and :meth:`readlines` are not
+       WSGI compliant because it passes a size argument to the
+       readline methods.  Unfortunately the WSGI PEP is not safely
+       implementable without a size argument to :meth:`readline`
+       because there is no EOF marker in the stream.  As a result
+       of that the use of :meth:`readline` is discouraged.
+
+       For the same reason iterating over the :class:`LimitedStream`
+       is not portable.  It internally calls :meth:`readline`.
+
+       We strongly suggest using :meth:`read` only or using the
+       :func:`make_line_iter` which safely iterates line-based
+       over a WSGI input stream.
+
+    :param stream: the stream to wrap.
+    :param limit: the limit for the stream, must not be longer than
+                  what the string can provide if the stream does not
+                  end with `EOF` (like `wsgi.input`)
+    """
+
+    def __init__(self, stream, limit):
+        self._read = stream.read
+        self._readline = stream.readline
+        self._pos = 0
+        self.limit = limit
+
+    def __iter__(self):
+        return self
+
+    @property
+    def is_exhausted(self):
+        """If the stream is exhausted this attribute is `True`."""
+        return self._pos >= self.limit
+
+    def on_exhausted(self):
+        """This is called when the stream tries to read past the limit.
+        The return value of this function is returned from the reading
+        function.
+        """
+        # Read null bytes from the stream so that we get the
+        # correct end of stream marker.
+        return self._read(0)
+
+    def on_disconnect(self):
+        """What should happen if a disconnect is detected?  The return
+        value of this function is returned from read functions in case
+        the client went away.  By default a
+        :exc:`~werkzeug.exceptions.ClientDisconnected` exception is raised.
+        """
+        from .exceptions import ClientDisconnected
+
+        raise ClientDisconnected()
+
+    def exhaust(self, chunk_size=1024 * 64):
+        """Exhaust the stream.  This consumes all the data left until the
+        limit is reached.
+
+        :param chunk_size: the size for a chunk.  It will read the chunk
+                           until the stream is exhausted and throw away
+                           the results.
+        """
+        to_read = self.limit - self._pos
+        chunk = chunk_size
+        while to_read > 0:
+            chunk = min(to_read, chunk)
+            self.read(chunk)
+            to_read -= chunk
+
+    def read(self, size=None):
+        """Read `size` bytes or if size is not provided everything is read.
+
+        :param size: the number of bytes read.
+        """
+        if self._pos >= self.limit:
+            return self.on_exhausted()
+        if size is None or size == -1:  # -1 is for consistence with file
+            size = self.limit
+        to_read = min(self.limit - self._pos, size)
+        try:
+            read = self._read(to_read)
+        except (IOError, ValueError):
+            return self.on_disconnect()
+        if to_read and len(read) != to_read:
+            return self.on_disconnect()
+        self._pos += len(read)
+        return read
+
+    def readline(self, size=None):
+        """Reads one line from the stream."""
+        if self._pos >= self.limit:
+            return self.on_exhausted()
+        if size is None:
+            size = self.limit - self._pos
+        else:
+            size = min(size, self.limit - self._pos)
+        try:
+            line = self._readline(size)
+        except (ValueError, IOError):
+            return self.on_disconnect()
+        if size and not line:
+            return self.on_disconnect()
+        self._pos += len(line)
+        return line
+
+    def readlines(self, size=None):
+        """Reads a file into a list of strings.  It calls :meth:`readline`
+        until the file is read to the end.  It does support the optional
+        `size` argument if the underlaying stream supports it for
+        `readline`.
+        """
+        last_pos = self._pos
+        result = []
+        if size is not None:
+            end = min(self.limit, last_pos + size)
+        else:
+            end = self.limit
+        while 1:
+            if size is not None:
+                size -= last_pos - self._pos
+            if self._pos >= end:
+                break
+            result.append(self.readline(size))
+            if size is not None:
+                last_pos = self._pos
+        return result
+
+    def tell(self):
+        """Returns the position of the stream.
+
+        .. versionadded:: 0.9
+        """
+        return self._pos
+
+    def __next__(self):
+        line = self.readline()
+        if not line:
+            raise StopIteration()
+        return line
+
+    def readable(self):
+        return True
+
+
+# DEPRECATED
+from .middleware.dispatcher import DispatcherMiddleware as _DispatcherMiddleware
+from .middleware.http_proxy import ProxyMiddleware as _ProxyMiddleware
+from .middleware.shared_data import SharedDataMiddleware as _SharedDataMiddleware
+
+
+class ProxyMiddleware(_ProxyMiddleware):
+    """
+    .. deprecated:: 0.15
+        ``werkzeug.wsgi.ProxyMiddleware`` has moved to
+        :mod:`werkzeug.middleware.http_proxy`. This import will be
+        removed in 1.0.
+    """
+
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.wsgi.ProxyMiddleware' has moved to 'werkzeug"
+            ".middleware.http_proxy.ProxyMiddleware'. This import is"
+            " deprecated as of version 0.15 and will be removed in"
+            " version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(ProxyMiddleware, self).__init__(*args, **kwargs)
+
+
+class SharedDataMiddleware(_SharedDataMiddleware):
+    """
+    .. deprecated:: 0.15
+        ``werkzeug.wsgi.SharedDataMiddleware`` has moved to
+        :mod:`werkzeug.middleware.shared_data`. This import will be
+        removed in 1.0.
+    """
+
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.wsgi.SharedDataMiddleware' has moved to"
+            " 'werkzeug.middleware.shared_data.SharedDataMiddleware'."
+            " This import is deprecated as of version 0.15 and will be"
+            " removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(SharedDataMiddleware, self).__init__(*args, **kwargs)
+
+
+class DispatcherMiddleware(_DispatcherMiddleware):
+    """
+    .. deprecated:: 0.15
+        ``werkzeug.wsgi.DispatcherMiddleware`` has moved to
+        :mod:`werkzeug.middleware.dispatcher`. This import will be
+        removed in 1.0.
+    """
+
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            "'werkzeug.wsgi.DispatcherMiddleware' has moved to"
+            " 'werkzeug.middleware.dispatcher.DispatcherMiddleware'."
+            " This import is deprecated as of version 0.15 and will be"
+            " removed in version 1.0.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        super(DispatcherMiddleware, self).__init__(*args, **kwargs)