Bug in compose-mail with mh-e-user-agent

[Dan Dever]

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Please write in English, because the Emacs maintainers do not have
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In GNU Emacs 20.7.1 (alphaev56-dec-osf4.0f, X toolkit)
 of Wed Feb 21 2001 on pia002.hlo.dec.com

  mh-e info:

version: $Id: mh-e.el,v 1.20 1998/05/03 07:34:07 rms Exp $
Emacs: 20.7.1 on berkeley-unix OSF1 squirm.hlo.dec.com V4.0 1229 alpha


  MH info:

/usr/bin/mh/inc:
version: MH 6.7 #1[UCI] (morley.zk3.dec.com) of Mon Apr 12 12:50:29 EDT 1999
options: [SYS5DIR] [_BSD] [ISI] [MHRC] [WHATNOW] [MHE] [BSD42] [BERK]
         [BSD43] [LOCKF] [NETWORK] [BIND] [RPATHS] [DPOP] [RPOP] [UK]
         [FOLDPROT='"0700"'] [MSGPROT='"0600"'] [TYPESIG='void']
         [POPSERVICE='"pop"'] [SPRINTF='int'] [SENDMTS] [SMTP] [POP]
         [X400]

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

C-x m (compose-mail) fails for me if mail-user-agent is set to
mh-e-user-agent.

Example sequence:

Here are the entire contents of my .emacs file:
    (setq mail-user-agent 'mh-e-user-agent)

I type C-x m.  I get this error message:
    Wrong type argument: char-or-string-p, nil              

The problem seems to be that mh-smail-batch (in mh-comp.el)
calls mh-send with a subject equal to nil.  Then mh-send passes
this nil subject to mh-send-sub which passes it on to
mh-insert-fields, which finally tries to insert nil.  The insert
function wants a character or a string, not nil, and issues the
error message above.

Here's a version of mh-smail-batch that seems to fix the
problem.  All I've done is replace subject with (or subject "")
in the call to mh-send:

(defun mh-smail-batch (&optional to subject other-headers &rest ignored)
  "Set up a mail composition draft with the MH mail system.
This function is an entry point to mh-e, the Emacs front end
to the MH mail system.  This function does not prompt the user
for any header fields, and thus is suitable for use by programs
that want to create a mail buffer.
Users should use `\\[mh-smail]' to compose mail."
  (mh-find-path)
  (let ((mh-error-if-no-draft t))
    (mh-send (or to "") "" (or subject ""))))

Regards, 
Dan (dever@segsrv.hlo.dec.com)

Recent input:
C-x m ESC x r e p o r t - e m a c s - b u g return

Recent messages:
For information about the GNU Project and its goals, type C-h C-p.
Loading mh-comp...
Loading mh-comp...done
Composing a message...
Wrong type argument: char-or-string-p, nil
Auto-saving...
Wrong type argument: char-or-string-p, nil
Loading emacsbug...
Loading emacsbug...done