On 2 or 3 occasions in the last few days, when trying to save an edit I have
gotten the message "You have not provided an edit summary. If you click Save
again, your edit will be saved without one." even though the edit summary
OTOH, I have saved dozens of edits without getting this message. I haven't
noticed any pattern in which Saves go wrong. (*@#&+! Heisenbugs.)
This problem is extremely minor; I'm only reporting it in case it's part of a
more significant problem.