[jsinterp] Fix for youtube player 1f7d5369

Closes #4635 again

2 files changed, 56 insertions, 19 deletions

diff --git a/yt_dlp/extractor/youtube.py b/yt_dlp/extractor/youtube.py
index 12634483e..795a4f42f 100644
--- a/yt_dlp/extractor/youtube.py
+++ b/yt_dlp/extractor/youtube.py
@@ -2652,9 +2652,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
 
         if self.get_param('youtube_print_sig_code'):
             self.to_screen(f'Extracted nsig function from {player_id}:\n{func_code[1]}\n')
-
         func = jsi.extract_function_from_code(*func_code)
-        return lambda s: func([s])
+
+        def inner(s):
+            ret = func([s])
+            if ret.startswith('enhanced_except_'):
+                raise ExtractorError('Signature function returned an exception')
+            return ret
+        return inner
 
     def _extract_signature_timestamp(self, video_id, player_url, ytcfg=None, fatal=False):
         """
diff --git a/yt_dlp/jsinterp.py b/yt_dlp/jsinterp.py
index 47cca1176..d3994e90c 100644
--- a/yt_dlp/jsinterp.py
+++ b/yt_dlp/jsinterp.py
@@ -24,9 +24,9 @@ _OPERATORS = {  # None => Defined in JSInterpreter._operator
 
     '||': None,
     '&&': None,
-    '&': operator.and_,
-    '|': operator.or_,
-    '^': operator.xor,
+    '&': lambda a, b: (a or 0) & (b or 0),
+    '|': lambda a, b: (a or 0) | (b or 0),
+    '^': lambda a, b: (a or 0) ^ (b or 0),
 
     '===': operator.is_,
     '!==': operator.is_not,
@@ -45,8 +45,8 @@ _OPERATORS = {  # None => Defined in JSInterpreter._operator
     '-': lambda a, b: (a or 0) - (b or 0),
 
     '*': lambda a, b: (a or 0) * (b or 0),
-    '/': lambda a, b: (a or 0) / b,
-    '%': operator.mod,
+    '/': lambda a, b: (a or 0) / b if b else float('NaN'),
+    '%': lambda a, b: (a or 0) % b if b else float('NaN'),
 
     '**': operator.pow,
 }
@@ -54,7 +54,7 @@ _OPERATORS = {  # None => Defined in JSInterpreter._operator
 _COMP_OPERATORS = {'===', '!==', '==', '!=', '<=', '>=', '<', '>'}
 
 _MATCHING_PARENS = dict(zip('({[', ')}]'))
-_QUOTES = '\'"'
+_QUOTES = '\'"/'
 
 
 def _ternary(cndn, if_true=True, if_false=False):
@@ -77,6 +77,12 @@ class JS_Continue(ExtractorError):
         ExtractorError.__init__(self, 'Invalid continue')
 
 
+class JS_Throw(ExtractorError):
+    def __init__(self, e):
+        self.error = e
+        ExtractorError.__init__(self, f'Uncaught exception {e}')
+
+
 class LocalNameSpace(collections.ChainMap):
     def __setitem__(self, key, value):
         for scope in self.maps:
@@ -131,19 +137,24 @@ class JSInterpreter:
 
     @staticmethod
     def _separate(expr, delim=',', max_split=None):
+        OP_CHARS = '+-*/%&|^=<>!,;'
         if not expr:
             return
         counters = {k: 0 for k in _MATCHING_PARENS.values()}
         start, splits, pos, delim_len = 0, 0, 0, len(delim) - 1
-        in_quote, escaping = None, False
+        in_quote, escaping, after_op, in_regex_char_group = None, False, True, False
         for idx, char in enumerate(expr):
             if not in_quote and char in _MATCHING_PARENS:
                 counters[_MATCHING_PARENS[char]] += 1
             elif not in_quote and char in counters:
                 counters[char] -= 1
             elif not escaping and char in _QUOTES and in_quote in (char, None):
-                in_quote = None if in_quote else char
+                if in_quote or after_op or char != '/':
+                    in_quote = None if in_quote and not in_regex_char_group else char
+            elif in_quote == '/' and char in '[]':
+                in_regex_char_group = char == '['
             escaping = not escaping and in_quote and char == '\\'
+            after_op = not in_quote and char in OP_CHARS or (char == ' ' and after_op)
 
             if char != delim[pos] or any(counters.values()) or in_quote:
                 pos = 0
@@ -210,16 +221,22 @@ class JSInterpreter:
             if should_return:
                 return ret, should_return
 
-        m = re.match(r'(?P<var>(?:var|const|let)\s)|return(?:\s+|$)', stmt)
+        m = re.match(r'(?P<var>(?:var|const|let)\s)|return(?:\s+|(?=["\'])|$)|(?P<throw>throw\s+)', stmt)
         if m:
             expr = stmt[len(m.group(0)):].strip()
+            if m.group('throw'):
+                raise JS_Throw(self.interpret_expression(expr, local_vars, allow_recursion))
             should_return = not m.group('var')
         if not expr:
             return None, should_return
 
         if expr[0] in _QUOTES:
             inner, outer = self._separate(expr, expr[0], 1)
-            inner = json.loads(js_to_json(f'{inner}{expr[0]}', strict=True))
+            if expr[0] == '/':
+                inner = inner[1:].replace('"', R'\"')
+                inner = re.compile(json.loads(js_to_json(f'"{inner}"', strict=True)))
+            else:
+                inner = json.loads(js_to_json(f'{inner}{expr[0]}', strict=True))
             if not outer:
                 return inner, should_return
             expr = self._named_object(local_vars, inner) + outer
@@ -263,21 +280,36 @@ class JSInterpreter:
                 for item in self._separate(inner)])
             expr = name + outer
 
-        m = re.match(r'(?P<try>try|finally)\s*|(?:(?P<catch>catch)|(?P<for>for)|(?P<switch>switch))\s*\(', expr)
+        m = re.match(rf'''(?x)
+            (?P<try>try|finally)\s*|
+            (?P<catch>catch\s*(?P<err>\(\s*{_NAME_RE}\s*\)))|
+            (?P<switch>switch)\s*\(|
+            (?P<for>for)\s*\(|''', expr)
         if m and m.group('try'):
             if expr[m.end()] == '{':
                 try_expr, expr = self._separate_at_paren(expr[m.end():], '}')
             else:
                 try_expr, expr = expr[m.end() - 1:], ''
-            ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion)
-            if should_abort:
-                return ret, True
+            try:
+                ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion)
+                if should_abort:
+                    return ret, True
+            except JS_Throw as e:
+                local_vars['__ytdlp_exception__'] = e.error
+            except Exception as e:
+                # XXX: This works for now, but makes debugging future issues very hard
+                local_vars['__ytdlp_exception__'] = e
             ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion)
             return ret, should_abort or should_return
 
         elif m and m.group('catch'):
-            # We ignore the catch block
-            _, expr = self._separate_at_paren(expr, '}')
+            catch_expr, expr = self._separate_at_paren(expr[m.end():], '}')
+            if '__ytdlp_exception__' in local_vars:
+                catch_vars = local_vars.new_child({m.group('err'): local_vars.pop('__ytdlp_exception__')})
+                ret, should_abort = self.interpret_statement(catch_expr, catch_vars, allow_recursion)
+                if should_abort:
+                    return ret, True
+
             ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion)
             return ret, should_abort or should_return
 
@@ -390,7 +422,7 @@ class JSInterpreter:
                 raise self.Exception(f'List index {idx} must be integer', expr)
             idx = int(idx)
             left_val[idx] = self._operator(
-                m.group('op'), left_val[idx], m.group('expr'), expr, local_vars, allow_recursion)
+                m.group('op'), self._index(left_val, idx), m.group('expr'), expr, local_vars, allow_recursion)
             return left_val[idx], should_return
 
         elif expr.isdigit():