This bug was reproduced on the English Wikipedia.
Steps to reproduce:
- Open an existing page for edition using the Visual Editor (ie: a test page in your user space) in browser 1.
- Using an anonymous user on browser 2 (an incognito window for example) make edits to that page so as to create an edit conflict.
- Save the page on browser 2.
- With browser 1, save the page. The VisualEditor will inform you that a conflict has been detected.
- Press the button for conflict resolution.
- The user gets taken to a wikicode editor for a previous version of the page.
- An error message informing that "Some parts of the edit form did not reach the server; double-check that your edits are intact and try again." is displayed
- When "Publish changes" is pressed, the user is then taken to the conflict resolution interface.
- That the user be shown the conflict resolution interface right away.