bug#11660: 24.1; Supercite doesn't work with RMAIL in 24.1

[Eli Zaretskii <eliz@gnu.org>]

> From: Kenichi Handa <handa@gnu.org>
> Date: Sun, 10 Jun 2012 00:16:47 +0900
> 
> With the release candidata of 24.1, supercite doesn't work
> with RMAIL.  This is what I tried:
> 
> # In RMAIL buffer showing a message from Kenichi Handa (it's me):
> r
> # Now I'm in "*unsent mail to Kenichi*".
> C-c C-y
> # The buffer shows the original message (head and body), and
> # the minibuffer prompts "Complete attribution name:" and
> # shows the default input "Anon".
> RET
> # The "*unsent..." buffer inserts " writes" at the first line
> # of the composing body, and the following lines are not
> # cited by "> ".
> 
> Previously (in Emacs 23), C-c C-y RET inserts this line at
> the first line:
>   "In article <87boks4k41.fsf@gnu.org>, Kenichi Handa <handa@gnu.org> writes:"
> and the following lines (containing only the body of the
> original) are cited properly.

Whatever is done to fix this, _please_ test the changes, if any, also
with mail-user-agent set to sendmail-user-agent.  Too many times this
configuration was broken during the last stages of pretest by changes
to either rmail*.el or sendmail.el, which suggests that the changes
are only tested with the default mail-user-agent.

TIA