Steps to replicate the issue (include links if applicable):
- In extension/CampaignEvents/src/Special/SpecialAllEvents, make the setSubmitCallback function return \MediaWiki\Status\Status::newFatal('test') instead of true.
- Note that we need this because the form currently has no validation, and therefore it's not possible to trigger any validation errors. This could've been reproduced differently before T362895 was fixed.
- Go to Special:AllEvents
- Click "Apply filters"
What happens?:
The error message follows the grid layout, and pushes all the form fields back, as can be seen in the following screenshot:
What should have happened instead?:
The error message should not be part of the grid layout.
Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia): master

