Ben Maughan over at Pragmatic Emacs has a handy tip that I didn’t know about. Sometimes it’s convenient to see the differences between the current buffer and the underlying on-disk file. Emacs, of course, has you covered. Just call ediff-current-file to get a diff between the buffer and the file.
It’s not hard to understand how this handy command escaped my notice; it’s not in the ediff menu. I don’t use the menu for operations, of course, but it’s a good way of discovering commands for a particular area. Even if you read the ediff menu, it’s easy to miss particular commands but the menu makes them stand out.
In any event, thanks to Maughan for pointing out this useful command. If you aren’t already following Pragmatic Emacs, you really should add it to your feed. It’s full of good material.