TYPO3 Core

This bug might not be triggered often as it only happens under specific circumstances, but still...

Manual process to reproduce:
1. Change a tt_content record in workspace
2. Go to workspace module
3. Push the changes to the last stage before Publishing
4. Open a new tab and go to the workspace module as well; you should now have to tabs open, both showing the same record.
5. Publish the record in the first tab. Test and see that everything is fine, the changes got to LIVE.
6. Publish the record in the second tab using the ACTION dropdown (this is important as only the ACTION dropdown triggers the issue).
7. Everything is reverted again and the changes are no longer visible in the Workspace (in the DB, the old workspace version of the record has wsid = 0 and pid = -1 and is thus invisible, but still contains the correct content).

Possible explanations:
- User had two tabs open
- Two users both published within 30 seconds of one another
- AJAX Request was fired twice? Somehow...

Important: Running the functional test requires a patched EXT:phpunit, see https://review.typo3.org/#/c/26743/