Namespace filtering is not working in watchlist on trunk. The broke somewhere between r62000 and r63000. Didn't have time to narrow it down further.

Steps to reproduce:

1. Have a user logged in
2. create a page in the main namespace. Add it to logged in user's watchlist
3. create a page in the project namespace. Add it to logged in user's watchlist
4. go to Special:Watchlist
5. ensure that own edits are show ('Hide my edits' should be displayed'.

Observed: the two pages from steps 2 and 3 are at least shown in the watchlist

6. select "Project" in the namespace selector.
7. Click "OK"

Observed: the two pages from steps 2 and 3 are at least shown in the watchlist. The page from the main namespace is not filtered out.

Expected: Only pages on user's watchlist in the project namespace should be shown.

Version: 1.17.x
Severity: normal