Steps to reproduce: User A and User B are editing section 5 of article (probably discussion page) X. User B finishes their edit, and it goes through. User A, however, is still working on his edit. He finally finishes and submits, but there's an edit conflict.
Edit screen comes back on, showing just the section and edit conflict info.
Edit screen comes back on, showing *entire* article and edit conflict info.
This is quite annoying on discussion pages, because they can get long, they can get lots of edit conflicts, and if you suddenly have to edit the entire page, you've got to find the section again, and then edit it.
Possible problems fixing it:
This is likely an approach that helps prevent strange things from happening when section are reordered/added/deleted. In order to keep the current behavior in these cases, we would have to know whether or not edits changed the section layouts. This would require a new database column unfortunantely.
An alternative solution, likely a feature request, is to have display only the edit conflicting sections in the edit box, making it irrelevant "where" on the page the edit is. This would likely merit a different bug.
See Also: T2980