Steps to reproduce:
- attempt to add a caption to existing file
- once caption is added 'cancel' and 'publish' buttons do not get hidden
- error in console jQuery.Deferred exception: self.languageSelectors[index] is undefined
Steps to reproduce:
Change 499553 had a related patch set uploaded (by Cparle; owner: Cparle):
[mediawiki/extensions/WikibaseMediaInfo@master] Trigger confirm when cancel button is clicked instead of in makeReadOnly()
Change 499553 merged by jenkins-bot:
[mediawiki/extensions/WikibaseMediaInfo@master] Trigger confirm when cancel button is clicked instead of in makeReadOnly()
For posterity: this bug was regression caused by T219197 which had recently merged. We luckily noticed it on beta before it got any further.