If you submit a comment with a "plan changes" action, the comment gets submitted, but it also remains as an unsubmitted comment.

Version: 067d12d7168a

Repro steps:

1. Submit a diff
2. Select "Plan Changes" from the "Action" menu, write a comment, and submit.
3. View the diff. The comment has been submitted, but the text still populates the "comment" box.

3a) View the home screen. The diff has a yellow "Unsubmitted comments" icon.