Hi!
I moved the shortcut below the hook execution in r32354. If a hook is running too slowly, it should be fixed, not the call to wfRunHooks.
Well, the major issue then is to check for 'read' condition in any extension that uses userCan hook, and do fast execution without unstubbing too many objects.
but check $wgGroupPermissions. Domas, could you explain? Or someone?
and unstubs the User object, which can be skipped in quite many code executions :)