If you have an inline comment in-progress somewhere on a diff and try to double click a line to start another, nothing will happen. It’s so frustrating. I've finally trained myself to realize that it means I have a comment open somewhere else and scroll to find it. I have lost a few long unfinished comments in the past because I didn't know what was wrong so I refreshed and then my unfinished comment was gone. A prompt would be nice here.