Presumably a bug introduced in 1.18, possibly very recently given it wasn't there when mw.org was switched to 1.18 originally.

Sidebar looks like (just one section given):

support

• Help
• manual-text
• FAQ
• Support desk

Where, support should be the content of [[mw:Mediawiki:Support]], manual-text should be whatever is in [[mw:Mediawiki:manual-text]]. The urls the links go to suffer from a similar issue.

This doesn't appear in a quick test of my local 1.18wmf1 checkout (but given this seems to only happen to random sidebar entries, I guess that doesn't mean much, I might just not have triggered the bug in my quick local test).

Which entries correctly use the contents of the message seem random. All of the bad entries seem to be one's utilizing custom messages, but some of the entries using custom messages are unaffected.

Note, setting the ?uselang url parameter to something not-english seems to make the problem go away (of course the interface is no longer english). However, I don't think $wgEnableSidebarCache is enabled on mw.org, so it is probably not a one-time issue with sidebar generation that got cached (but may be wrong on that). Maybe something to do with however messages are cached given it only seems to affect "custom" messages?

Version: 1.18.x
Severity: major