The behavior of the ignorewarnings parameter in action=upload was changed [1] recently. The ignorewarnings parameter causes an upload to go through even if there were (non-fatal) warnings. Previously, it also removed the warnings from the API output, but with Mark's recent change, these warnings will now be shown. Clients that check for "Success" or "Warning" shouldn't break, but clients that only check for the <warnings> element to see if an upload failed may start failing.

This change will be part of the 1.20wmf9 deployment, which will go live on WMF wikis in stages between August 6 and August 13 [2].

Roan

[1] https://gerrit.wikimedia.org/r/#/c/9261/ [2] https://www.mediawiki.org/wiki/MediaWiki_1.20/Roadmap#Schedule_for_the_deplo...