bug#25040: 24.5; setting mail-interactive to nil causes error while sending

["Francesco Potortì" <pot@gnu.org>]

In sendmail.el I find this:

================
(defun sendmail-send-it ()
  "Send the current mail buffer using the Sendmail package.
This is a suitable value for `send-mail-function'.  It sends using the
external program defined by `sendmail-program'."
  (require 'mail-utils)
  (let ((errbuf (if mail-interactive
		    (generate-new-buffer " sendmail errors")
		  0))
================

However, the final 0 makes no sense to me, and in fact it generates an
error when sending mail if mail-interactive is set to nil.

Changing the 0 to nil apparently corrects the problem.


In GNU Emacs 24.5.1 (x86_64-pc-linux-gnu, GTK+ Version 3.21.5)
 of 2016-09-05 on trouble, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.11804000
System Description:	Debian GNU/Linux testing (stretch)

Configured using:
 `configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --with-pop=yes
 --enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.5/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.5/site-lisp:/usr/share/emacs/site-lisp
 --build x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
 --libexecdir=/usr/lib --localstatedir=/var/lib
 --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes
 --enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.5/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.5/site-lisp:/usr/share/emacs/site-lisp
 --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars
 'CFLAGS=-g -O2
 -fdebug-prefix-map=/build/emacs24-24.5+1=. -fstack-protector-strong
 -Wformat -Werror=format-security -Wall' 'CPPFLAGS=-Wdate-time
 -D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro'

Important settings:
  value of $LC_COLLATE: it_IT.UTF-8
  value of $LC_CTYPE: it_IT.UTF-8
  value of $LC_NUMERIC: C
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: RMAIL

Minor modes in effect:
  TeX-PDF-mode: t
  desktop-save-mode: t
  shell-dirtrack-mode: t
  openwith-mode: t
  xterm-mouse-mode: t
  display-time-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t

Recent messages:
Quit
Unsent message being composed; erase it? (y or n) n
Auto save file for draft message exists; consider M-x mail-recover
sendmail-user-agent-compose: Message aborted
Make carbon copy before sending? (y or n) y
Unfrobbing selective-display...
Sending...
Added to /home/pot/Mail/backup/SMAIL
Sending...done
Report a bug for a [P]ackage or [F]ile: (default P) 
Quit

Load-path shadows:
~/elisp/bhl hides /usr/share/emacs/24.5/site-lisp/bhl
~/elisp/bhl hides /usr/share/emacs/site-lisp/bhl
/usr/share/emacs/24.5/site-lisp/debian-startup hides /usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs24/site-lisp/flim/md4 hides /usr/share/emacs/24.5/lisp/md4
/usr/share/emacs24/site-lisp/flim/hex-util hides /usr/share/emacs/24.5/lisp/hex-util
/usr/share/emacs/site-lisp/rst hides /usr/share/emacs/24.5/lisp/textmodes/rst
/usr/share/emacs24/site-lisp/flim/ntlm hides /usr/share/emacs/24.5/lisp/net/ntlm
/usr/share/emacs24/site-lisp/flim/hmac-md5 hides /usr/share/emacs/24.5/lisp/net/hmac-md5
/usr/share/emacs24/site-lisp/flim/sasl-ntlm hides /usr/share/emacs/24.5/lisp/net/sasl-ntlm
/usr/share/emacs24/site-lisp/flim/sasl-digest hides /usr/share/emacs/24.5/lisp/net/sasl-digest
/usr/share/emacs24/site-lisp/flim/sasl hides /usr/share/emacs/24.5/lisp/net/sasl
/usr/share/emacs24/site-lisp/flim/sasl-cram hides /usr/share/emacs/24.5/lisp/net/sasl-cram
/usr/share/emacs24/site-lisp/flim/hmac-def hides /usr/share/emacs/24.5/lisp/net/hmac-def
~/elisp/emacs24/sendmail hides /usr/share/emacs/24.5/lisp/mail/sendmail
/usr/share/emacs24/site-lisp/auctex/tex-fold hides /usr/share/emacs/site-lisp/auctex/tex-fold
/usr/share/emacs24/site-lisp/auctex/context-en hides /usr/share/emacs/site-lisp/auctex/context-en
/usr/share/emacs24/site-lisp/auctex/tex-info hides /usr/share/emacs/site-lisp/auctex/tex-info
/usr/share/emacs24/site-lisp/auctex/plain-tex hides /usr/share/emacs/site-lisp/auctex/plain-tex
/usr/share/emacs24/site-lisp/auctex/tex-mik hides /usr/share/emacs/site-lisp/auctex/tex-mik
/usr/share/emacs24/site-lisp/auctex/texmathp hides /usr/share/emacs/site-lisp/auctex/texmathp
/usr/share/emacs24/site-lisp/auctex/context-nl hides /usr/share/emacs/site-lisp/auctex/context-nl
/usr/share/emacs24/site-lisp/auctex/toolbar-x hides /usr/share/emacs/site-lisp/auctex/toolbar-x
/usr/share/emacs24/site-lisp/auctex/tex hides /usr/share/emacs/site-lisp/auctex/tex
/usr/share/emacs24/site-lisp/auctex/tex-jp hides /usr/share/emacs/site-lisp/auctex/tex-jp
/usr/share/emacs24/site-lisp/auctex/bib-cite hides /usr/share/emacs/site-lisp/auctex/bib-cite
/usr/share/emacs24/site-lisp/auctex/multi-prompt hides /usr/share/emacs/site-lisp/auctex/multi-prompt
/usr/share/emacs24/site-lisp/auctex/font-latex hides /usr/share/emacs/site-lisp/auctex/font-latex
/usr/share/emacs24/site-lisp/auctex/prv-emacs hides /usr/share/emacs/site-lisp/auctex/prv-emacs
/usr/share/emacs24/site-lisp/auctex/tex-style hides /usr/share/emacs/site-lisp/auctex/tex-style
/usr/share/emacs24/site-lisp/auctex/context hides /usr/share/emacs/site-lisp/auctex/context
/usr/share/emacs24/site-lisp/auctex/preview hides /usr/share/emacs/site-lisp/auctex/preview
/usr/share/emacs24/site-lisp/auctex/tex-font hides /usr/share/emacs/site-lisp/auctex/tex-font
/usr/share/emacs24/site-lisp/auctex/tex-bar hides /usr/share/emacs/site-lisp/auctex/tex-bar
/usr/share/emacs24/site-lisp/auctex/latex hides /usr/share/emacs/site-lisp/auctex/latex
/usr/share/emacs24/site-lisp/auctex/tex-buf hides /usr/share/emacs/site-lisp/auctex/tex-buf
/usr/share/emacs24/site-lisp/mailcrypt/expect hides /usr/share/emacs/site-lisp/mailcrypt/expect
/usr/share/emacs24/site-lisp/mailcrypt/mc-pgp5 hides /usr/share/emacs/site-lisp/mailcrypt/mc-pgp5
/usr/share/emacs24/site-lisp/mailcrypt/mc-pgp6 hides /usr/share/emacs/site-lisp/mailcrypt/mc-pgp6
/usr/share/emacs24/site-lisp/mailcrypt/mc-pgp hides /usr/share/emacs/site-lisp/mailcrypt/mc-pgp
/usr/share/emacs24/site-lisp/mailcrypt/mc-toplev hides /usr/share/emacs/site-lisp/mailcrypt/mc-toplev
/usr/share/emacs24/site-lisp/mailcrypt/mailcrypt hides /usr/share/emacs/site-lisp/mailcrypt/mailcrypt
/usr/share/emacs24/site-lisp/mailcrypt/mc-setversion hides /usr/share/emacs/site-lisp/mailcrypt/mc-setversion
/usr/share/emacs24/site-lisp/mailcrypt/mc-remail hides /usr/share/emacs/site-lisp/mailcrypt/mc-remail
/usr/share/emacs24/site-lisp/mailcrypt/mc-gpg hides /usr/share/emacs/site-lisp/mailcrypt/mc-gpg

Features:
(shadow emacsbug debian-bug locate derived eieio-opt speedbar sb-image
ezimage dframe find-func debug timezone rmailsort rmailout rmailkwd
macros rmailedit dired-aux cus-edit cus-start cus-load wid-edit
time-stamp mailalias misearch multi-isearch parse-time unrmail jka-compr
bibtex info sh-script smie executable sgml-mode cc-langs cc-mode
cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars
cc-defs image-mode conf-mode generic vc-rcs octave-mod latexenc
vc-dispatcher vc-svn preview prv-emacs tex-bar tex-buf toolbar-x
noutline outline font-latex latex easy-mmode edmacro kmacro tex-style
tex dbus xml crm tex-mode compile solar cal-dst qp rmailmm message mml
mml-sec mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader
mail-parse rfc2231 server desktop frameset xterm pot skeleton rmailsum
rmail warnings sendmail rfc2047 rfc2045 ietf-drums mail-utils
mime-compose view mule-util vc-hg appt diary-lib diary-loaddefs cal-menu
calendar cal-loaddefs tramp tramp-compat tramp-loaddefs trampver shell
pcomplete format-spec bhl switch-to-shell openwith hi-lock xt-mouse ffap
thingatpt url-parse auth-source eieio byte-opt bytecomp byte-compile
cl-extra cl-loaddefs cl-lib cconv eieio-core gnus-util time-date mm-util
mail-prsvr password-cache url-vars scroll-in-place filladapt advice
help-fns time quail help-mode mailcrypt rfc822 comint ansi-color ring
dired-x easymenu dired generic-x disp-table package epg-config debian-el
debian-el-loaddefs w3m-load vm-autoload vm-autoloads vm-version vm-vars
vm-init mailcrypt-init preview-latex tex-site auto-loads tooltip
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment
lisp-mode prog-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev minibuffer nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
dbusbind gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 409650 59058)
 (symbols 48 39634 11)
 (miscs 40 4543 3545)
 (strings 32 86666 12906)
 (string-bytes 1 2769122)
 (vectors 16 37806)
 (vector-slots 8 1529935 222788)
 (floats 8 520 384)
 (intervals 56 33359 40)
 (buffers 960 107))