The problem, of course, is that the temp file is deleted shortly
after "diff" exits, so the default revert-buffer function installed by
"diff" fails.  The simplest solution seems to be to install a new
revert-buffer function that redoes the whole process of checking for a
file buffer and writing the temp file.  The attached patch does a
minimal refactoring of "diff" and "diff-buffer-with-file" to do just
that, while trying to DTRT if the user renames the diff buffer or kills
the original buffer.

					-- Bob Rogers
					   http://www.rgrjr.com/