1. On a diff revision, click on a line to leave a comment
2. Type a comment in the field
3. Hit Cancel which will cause an "Undo" link to appear
4. On the same line click again to create new comment
5. Type a comment in the field
6. Hit Cancel which will cause an "Undo" link to appear
7. Click "Undo" - this will cause the comment to restore way below where it should
{F760253}
One of the first times I did this (though possibly slightly different set of steps), an error appeared on the page. I couldn't get it to happen again. The stacktrace on the server is: P1847
Phabricator is on f2b2264e8def0a69d1431f38c1d202273f95842b