bug#2941: rmail's new handling of Babyl files is odd

[Richard M Stallman]

    Now if I press "s" to save the buffer, it is saved without warning,
    clobbering the existing Babyl file. I was expecting a confirmation
    prompt.

There is no way to ask for confirmation when saving a file.  (Look at
basic-save-buffer.)  Therefore I made it ask for confirmation when you
make a "major" change, that would imply changing formats later if you save the 
results.

Each kind of change can be treated as major or minor.

Editing the message should be major; I overlooked that one.
Please try the patch below.

I decided to treat changes in labels as minor, because showing a
message clears the "unseen" attribute.  Treating that as major implies
querying hen it shows an unseen message, which is typically just after
visiting the file.

It would be possible to treat changes in "unseen" as minor
and changes in "deleted" as major, etc.


*** rmailedit.el.~1.57.~        2009-03-14 14:26:33.000000000 -0400
--- rmailedit.el        2009-04-10 06:35:10.000000000 -0400
***************
*** 117,122 ****
--- 117,123 ----
  (defun rmail-cease-edit ()
    "Finish editing message; switch back to Rmail proper."
    (interactive)
+   (rmail-change-format)
    (if (rmail-summary-exists)
        (with-current-buffer rmail-summary-buffer
        (rmail-summary-enable)))