It seems that someone's added a checkbox "Log me in globally" on
CentralAuth's modified Special:Userlogin. This is kind of not great in that
it clogs up the user interface with something that should always 100% of the
time be on, and should never be optional.
The feature request:
https://bugzilla.wikimedia.org/show_bug.cgi?id=20852
The commit:
http://www.mediawiki.org/wiki/Special:Code/MediaWiki/75041
If there's no strong objection, I'd like to revert it. If there really is
some very specific need for non-global logins (wtf?!) this should be
something that individual people who really need it can *get to* with their
secret wizard knowledge but not inflict on everyone else. ;)
-- brion