Gutter marks linger after edits

[michaelblyons]

If I fix a merge conflict by hand, the highlighting outline recognizes that the conflict no longer exists. The gutter icons, however, stick around. Save the following file:

If you have questions, please
<<<<<<< HEAD
open an issue.
|||||||
don't worry about it.
=======
ask your question in IRC.
>>>>>>> branch-a

Then, delete and edit lines¹ so it says:

If you have questions, please
open an issue and
ask your question in IRC.

The UI for lines 2-3 will still retain their arrows, kind of like this:

 1 If you have questions, please
←2 open an issue and
→3 ask your question in IRC.

I'd like it if the gutter was cleaned up along with the highlighting.

---

¹ If you just paste the text overtop instead of manually editing, the gutter behavior is slightly different, but still leaves a stray →.