1 files changed, 68 insertions, 3 deletions
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a98c53953..687b0ca5d 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -42,7 +42,9 @@ Before reporting any issue, type `doas pacman -Sy hypervideo`. This should repor
 
 ###  Is the issue already documented?
 
-Make sure that someone has not already opened the issue you're trying to open. Search at the top of the window or browse the [GitHub Issues](https://github.com/ytdl-org/youtube-dl/search?type=Issues) of this repository. If there is an issue, feel free to write something along the lines of "This affects me as well, with version 2015.01.01. Here is some more information on the issue: ...". While some issues may be old, a new post into them often spurs rapid activity.
+Make sure that someone has not already opened the issue you're trying to open. Search at the top of the window or browse the [GitHub Issues](https://github.com/yt-dlp/yt-dlp/search?type=Issues) of this repository. If there is an issue, subcribe to it to be notified when there is any progress. Unless you have something useful to add to the converation, please refrain from commenting.
+
+Additionally, it is also helpful to see if the issue has already been documented in the [youtube-dl issue tracker](https://github.com/ytdl-org/youtube-dl/issues). If similar issues have already been reported in youtube-dl (but not in our issue tracker), links to them can be included in your issue report here.
 
 ###  Why are existing options not enough?
 
@@ -64,7 +66,29 @@ In particular, every site support request issue should only pertain to services
 
 Only post features that you (or an incapacitated friend you can personally talk to) require. Do not post features because they seem like a good idea. If they are really useful, they will be requested by someone who requires them.
 
-###  Is your question about hypervideo?
+###  Is your question about yt-dlp?
+
+Some bug reports are completely unrelated to yt-dlp and relate to a different, or even the reporter's own, application. Please make sure that you are actually using yt-dlp. If you are using a UI for yt-dlp, report the bug to the maintainer of the actual application providing the UI. In general, if you are unable to provide the verbose log, you should not be opening the issue here.
+
+If the issue is with `youtube-dl` (the upstream fork of yt-dlp) and not with yt-dlp, the issue should be raised in the youtube-dl project.
+
+### Are you willing to share account details if needed?
+
+The maintainers and potential contributors of the project often do not have an account for the website you are asking support for. So any developer interested in solving your issue may ask you for account details. It is your personal discretion whether you are willing to share the account in order for the developer to try and solve your issue. However, if you are unwilling or unable to provide details, they obviously cannot work on the issue and it cannot be solved unless some developer who both has an account and is willing/able to contribute decides to solve it.
+
+By sharing an account with anyone, you agree to bear all risks associated with it. The maintainers and yt-dlp can't be held responsible for any misuse of the credentials.
+
+While these steps won't necessarily ensure that no misuse of the account takes place, these are still some good practices to follow.
+
+- Look for people with `Member` (maintainers of the project) or `Contributor` (people who have previously contributed code) tag on their messages.
+- Change the password before sharing the account to something random (use [this](https://passwordsgenerator.net/) if you don't have a random password generator).
+- Change the password after receiving the account back.
+
+### Is the website primarily used for piracy?
+
+We follow [youtube-dl's policy](https://github.com/ytdl-org/youtube-dl#can-you-add-support-for-this-anime-video-site-or-site-which-shows-current-movies-for-free) to not support services that is primarily used for infringing copyright. Additionally, it has been decided to not to support porn sites that specialize in fakes. We also cannot support any service that serves only [DRM protected content](https://en.wikipedia.org/wiki/Digital_rights_management).
+
+
 
 It may sound strange, but some bug reports we receive are completely unrelated to hypervideo and relate to a different, or even the reporter's own, application. Please make sure that you are actually using hypervideo. If you are using a UI for hypervideo, report the bug to the maintainer of the actual application providing the UI. On the other hand, if your UI for hypervideo fails in some way you believe is related to hypervideo, by all means, go ahead and report the bug.
 
@@ -173,7 +197,8 @@ In any case, thank you very much for your contributions!
 
 This section introduces a guide lines for writing idiomatic, robust and future-proof extractor code.
 
-Extractors are very fragile by nature since they depend on the layout of the source data provided by 3rd party media hosters out of your control and this layout tends to change. As an extractor implementer your task is not only to write code that will extract media links and metadata correctly but also to minimize dependency on the source's layout and even to make the code foresee potential future changes and be ready for that. This is important because it will allow the extractor not to break on minor layout changes thus keeping old hypervideo versions working. Even though this breakage issue is easily fixed by emitting a new version of hypervideo with a fix incorporated, all the previous versions become broken in all repositories and distros' packages that may not be so prompt in fetching the update from us. Needless to say, some non rolling release distros may never receive an update at all.
+Extractors are very fragile by nature since they depend on the layout of the source data provided by 3rd party media hosters out of your control and this layout tends to change. As an extractor implementer your task is not only to write code that will extract media links and metadata correctly but also to minimize dependency on the source's layout and even to make the code foresee potential future changes and be ready for that. This is important because it will allow the extractor not to break on minor layout changes thus keeping old yt-dlp versions working. Even though this breakage issue may be easily fixed by a new version of yt-dlp, this could take some time, during which the extractor will remain broken.
+
 
 ### Mandatory and optional metafields
 
@@ -239,6 +264,46 @@ description = self._search_regex(
 
 On failure this code will silently continue the extraction with `description` set to `None`. That is useful for metafields that may or may not be present.
 
+
+Another thing to remember is not to try to iterate over `None`
+
+Say you extracted a list of thumbnails into `thumbnail_data` and want to iterate over them
+
+```python
+thumbnail_data = data.get('thumbnails') or []
+thumbnails = [{
+    'url': item['url'],
+    'height': item.get('h'),
+} for item in thumbnail_data if item.get('url')]  # correct
+```
+
+and not like:
+
+```python
+thumbnail_data = data.get('thumbnails')
+thumbnails = [{
+    'url': item['url'],
+    'height': item.get('h'),
+} for item in thumbnail_data]  # incorrect
+```
+
+In this case, `thumbnail_data` will be `None` if the field was not found and this will cause the loop `for item in thumbnail_data` to raise a fatal error. Using `or []` avoids this error and results in setting an empty list in `thumbnails` instead.
+
+Alternately, this can be further simplified by using `traverse_obj`
+
+```python
+thumbnails = [{
+    'url': item['url'],
+    'height': item.get('h'),
+} for item in traverse_obj(data, ('thumbnails', lambda _, v: v['url']))]
+```
+
+or, even better,
+
+```python
+thumbnails = traverse_obj(data, ('thumbnails', ..., {'url': 'url', 'height': 'h'}))
+```
+
 ### Provide fallbacks
 
 When extracting metadata try to do so from multiple sources. For example if `title` is present in several places, try extracting from at least some of them. This makes it more future-proof in case some of the sources become unavailable.