Steps to Reproduce:
- Add a category "Happy" to the user page. ( for me it is User:FeliaBeHappy)
- Go to the category page for "Happy". ( Category:Happy)
- Notice that User:FeliaBeHappy is listed there.
- Actually all pages matching the category are listed, regardless of the namespaces they are in.
- Only pages from Main namespace are listed on the category page.
- Ideally There would be filters to decide what namespaces to include and what to exclude.
We have 1-line fix in current deployment now which adds 1 extra WHERE condition to the database query : namespace => NS_MAIN, but we would like to use hook instead of modifying core code. We are using some custom namespaces to implement new feature so those pages are purely internal and should not be available to the end users. I imagine the scenario is not uncommon and we would like hear what Mediawiki team would suggest.