- Visit https://en.m.wikipedia.beta.wmflabs.org/wiki/Spain
- Visit a page and click edit
- Type some text in the textarea
- Click the close icon in the top left corner
- Confirmation message appears. Click continue editing
- Confirm you stay in the overlay, the URL remains #/editor/0
- Type text in textarea
- Press browser back button
- Confirm you stay in the overlay
Expected: the URL remains #/editor/0
Actual: the URL becomes #/
Developer notes
This was flagged during QA of T218173 and can be fixed by making the editor overlay use the new onBeforeExit callback parameter.