Go to https://www.mediawiki.org/w/index.php?title=Download&useskin=monobook, click the site logo (#p-logo)
Expected: you go to the main page; actual: nothing happens
Possible regression from T170053 / 909aed3: The z-index removal may have caused div#column-content to cover #p-logo.
Sorry. Please trout me the next time I merge a patch only because the commit message proved it was correct, without properly testing it… I tested now and that is definitely the cause.
Change 366594 had a related patch set uploaded (by Bartosz Dziewoński; owner: Bartosz Dziewoński):
[mediawiki/skins/MonoBook@master] Revert "Remove position: absolute and z-index from #p-logo"
Change 366594 merged by jenkins-bot:
[mediawiki/skins/MonoBook@master] Revert "Remove position: absolute and z-index from #p-logo"
Change 366595 had a related patch set uploaded (by Bartosz Dziewoński; owner: Bartosz Dziewoński):
[mediawiki/skins/MonoBook@wmf/1.30.0-wmf.10] Revert "Remove position: absolute and z-index from #p-logo"
Change 366595 merged by jenkins-bot:
[mediawiki/skins/MonoBook@wmf/1.30.0-wmf.10] Revert "Remove position: absolute and z-index from #p-logo"
Mentioned in SAL (#wikimedia-operations) [2017-07-20T18:24:22Z] <thcipriani@tin> Synchronized php-1.30.0-wmf.10/skins/MonoBook/main.css: SWAT: [[gerrit:366595|Revert "Remove position: absolute and z-index from #p-logo"]] T171195 (duration: 00m 47s)