Setup: MediaWiki 1.31, PHP 7.2.14 (fpm-fcgi), MySQL 5.5.62-log (InnoDB), ICU 50.1.2
How to reproduce:
- Open a page in the editor
- Another user opens the same page in the editor, edits and saves it
- edit the page, and try to save it, so that the edit conflict form pops up
- after resolving the edit conflict click the 'save' button
The edit conflict resolution form gets loaded again, your edit doesn't get saved.
Your edit gets saved and the article page gets loaded
Reproduced the bug on machines with Firefox 64/ubuntu 16.4 LTS, Firefox 65/Windows 8.1 and Google Chrome/Windows 8.1. Skin was a basic Vector with no notable modifications, and the bug always occurs, the only way to save after an edit conflict occurred is by opening the article in question in the editor again and copy the changed wikicode into the editor.
URL to the wiki I encountered the bug: https://mariowiki.net