bug#2251: 23.0.90; Summary by label in RMAIL

[jpff <jpff@codemist.co.uk>]

In the pre-mbox file i see

1, edited,,
Summary-line: 10-Mar      mantaraya36@gmail.com  [24] #Re: Loadable Opcodes in OLPC
        x       X-Coding-System: iso-8859-1-unix
Mail-from: From mantaraya36@gmail.com Mon Mar 10 11:22:33 2008

Cannot chase this further back easily.

It survived for a long time before being a problem

By "not being able to read" I mean that when I do C-X f RMAIL it
loads the file in fundamental mode and I have to do a M-x rmail-mode
before it behaves.  Previously there was a 
BABYL OPTIONS: -*- rmail -*-
at the head of the file and so the mode was selected.  It is this I
have been unable to reproduce

Regarding unseen I have been using a function
(defun rmail-first-unseen ()
  (interactive)
  (rmail-show-message (rmail-first-unseen-message)))

for a while which I find very useful in the way I work.Now that
function fails -- either crashes or does not do anything.
I assumed this was because unseen was not set but I have not had time
to chase it.  Anyway is is a loss in functionality.

Happy to join in chasing these lacuna, as without emacs rmail-mode I
am lost

==John ffitch