Upstreamed as https://secure.phabricator.com/T5378
If I write http://fab.wmflabs.org/T413 in this comment you can't hover it to get its title: I must write T413 (happened in http://fab.wmflabs.org/T52#28 ).
Bugzilla was smarter and did both, <s>see e.g. https://bugzilla.wikimedia.org/show_bug.cgi?id=32940#c2 </s> (no longer works, because the url in the comment at old-bugzilla points to another subdomain)