Wikimedia Bugzilla is closed!

The function getQueryString in class SMWNamespaceDescription (SMW_Description.php) does not handle NS_CATEGORY namespace accordingly (see [0], [1]). : is not set in cases namespace = NS_CATEGORY and creates a problem in queries selecting on NS_CATEGORY pages.

[0] «Category» namespace, a : is again needed in front of the namespace label to prevent confusion, e.g. [[:Category:+]].

[1] http://www.semantic-mediawiki.org/wiki/Help:Selecting%20pages#Restricting_results_to_a_namespace

PS: I looked at the code and it seems not to have any special handling of NS_CATEGORY, so this must be broken since. Sorry I do not have the time to fixed this myself, so I just make note of it.