Inspired by this question: Can't edit question - title already exists
Synopsis: When editing a question that has a duplicate title, the system prompts the user (editor) to change the title, and won't allow any edits to be submitted without also editing the title.
It's very possible the original attempted edit to the question was to fix things unrelated to dupe (title or question), so the user will quite possibly just change the title to something suitable as they've been prompted to do, then make the edits they originally came to do, and be on their way.
However, if a question with a dupe title is also a dupe question (not just a dupe title, as is possible), then community moderating should handle it, and the edits unrelated to a "dupe-fix" the user makes will be pointless (or, not ideal, as it should be closed).
There is a simple missed opportunity here to get the problem fixed correctly, rather than just, as currently, "Edit this title or you cannot continue".
When trying to edit a question with a dupe title, it would perhaps be useful to inform the editor of the circumstances, so they can investigate.
This is a dupe title. If the question is a dupe, and you are not editing the question and title to fix the dupe, please flag the question instead of editing it. Otherwise, in addition to your edits, please also edit the title to remove the dupenicity