I think, after this warning, we must be brought to that active editor.
How to reproduce:
1. Edit first post, don't close the editor (scenario as you forgot it)
2. scroll down to the last post of the page.
3. Edit the last post.
4. I think we must be brought to the first post editor, so we can close it.
Chrome Version 55.0.2883.87 (64-bit)