bug#3521: 23.0.94; process-send-region errors / bug#2272 strikes again

bug#3521: 23.0.94; process-send-region errors / bug#2272 strikes again

[Tassilo Horn]

Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing list.

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

Evaluating this code once again triggers an error (I already reported it
in bug 2272 some times ago, and it was fixed and the bug closed):

--8<---------------cut here---------------start------------->8---
(progn
  (setq proctest
	(start-process "cat" (get-buffer-create "cat") "/bin/cat"))
  (with-temp-buffer
    (dotimes (dummy 999999)
      (insert
       (concat (number-to-string (random))
	       (number-to-string (random))
	       (number-to-string (random))
	       (number-to-string (random))
	       "\n")))
    (process-send-region proctest (point-min) (point-max)))
  (delete-process proctest))
--8<---------------cut here---------------end--------------->8---

Here's the backtrace:

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (file-error "writing to process" "bad address" #<process cat<2>>)
  process-send-region(#<process cat<2>> 1 75145548)
  (progn (dotimes (dummy 999999) (insert ...)) (process-send-region proctest (point-min) (point-max)))
  (unwind-protect (progn (dotimes ... ...) (process-send-region proctest ... ...)) (and (buffer-name temp-buffer) (kill-buffer temp-buffer)))
  (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn ... ...) (and ... ...)))
  (with-current-buffer temp-buffer (unwind-protect (progn ... ...) (and ... ...)))
  (let ((temp-buffer ...)) (with-current-buffer temp-buffer (unwind-protect ... ...)))
  (with-temp-buffer (dotimes (dummy 999999) (insert ...)) (process-send-region proctest (point-min) (point-max)))
  (progn (setq proctest (start-process "cat" ... "/bin/cat")) (with-temp-buffer (dotimes ... ...) (process-send-region proctest ... ...)) (delete-process proctest))
  eval((progn (setq proctest (start-process "cat" ... "/bin/cat")) (with-temp-buffer (dotimes ... ...) (process-send-region proctest ... ...)) (delete-process proctest)))
  eval-last-sexp-1(nil)
  eval-last-sexp(nil)
  call-interactively(eval-last-sexp nil nil)
--8<---------------cut here---------------end--------------->8---

Again, this bit me when Gnus tried to upload a sent message containing
some PDF attachments (~2MB) into an IMAP folder, and again this mail is
lost... :-(

This time I cannot reproduce this easily with emacs -Q, but with my
usual config it always happens.  But the test case above uses only very
low-level functions which shouldn't be influenced by any customization
anyway, right?  At none of them is redefined or adviced by me...

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/usr/share/emacs/23.0.94/etc/DEBUG for instructions.


In GNU Emacs 23.0.94.1 (x86_64-pc-linux-gnu, GTK+ Version 2.16.1)
 of 2009-06-08 on thinkpad
Windowing system distributor `The X.Org Foundation', version 11.0.10503000
configured using `configure  '--prefix=/usr' '--host=x86_64-pc-linux-gnu' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--datadir=/usr/share' '--sysconfdir=/etc' '--localstatedir=/var/lib' '--libdir=/usr/lib64' '--program-suffix=-emacs-23' '--infodir=/usr/share/info/emacs-23' '--with-sound' '--with-x' '--with-toolkit-scroll-bars' '--with-gif' '--with-jpeg' '--with-png' '--with-rsvg' '--with-tiff' '--with-xpm' '--with-xft' '--with-libotf' '--with-m17n-flt' '--with-x-toolkit=gtk' '--without-hesiod' '--with-kerberos' '--with-kerberos5' '--with-gpm' '--with-dbus' '--build=x86_64-pc-linux-gnu' 'build_alias=x86_64-pc-linux-gnu' 'host_alias=x86_64-pc-linux-gnu' 'CFLAGS=-g -ggdb -O1 -pipe' 'LDFLAGS=''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Group

Minor modes in effect:
  gnus-topic-mode: t
  gnus-undo-mode: t
  rcirc-track-minor-mode: t
  hl-line-mode: t
  yas/minor-mode: t
  recentf-mode: t
  window-number-meta-mode: t
  window-number-mode: t
  exec-abbrev-cmd-mode: t
  savehist-mode: t
  show-paren-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<down-mouse-2> <mouse-2> <left> C-x C-e <up> C-SPC 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> M-w q M-x g <return> 
<return> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> ^ q <return> y <return> 
<down> <return> <down> <return> <down> <return> <down> 
<return> q <return> <return> <return> <return> <return> 
<return> <return> <return> <return> <return> <return> 
<return> <return> <return> <return> q M-x r e b <r
eturn>

Recent messages:
20090610T122057.363> nnimap: Updating info for nnimap+Uni:ml/agebert...
20090610T122057.371> nnimap: Updating info for nnimap+Uni:ml/agebert...done
20090610T122057.372> Fetching headers for nnimap+Uni:ml/agebert...
20090610T122057.377> Fetching headers for nnimap+Uni:ml/agebert...done
20090610T122057.379> Generating summary...
20090610T122057.379> Generating summary...done
Adding "Re: [AG-Ebert] [Fwd:  Schreckensmeldung vom Uni-CMS]" to field "subjects"
20090610T122134.208> Exiting summary buffer and applying spam rules
20090610T122134.216> nnimap: Setting marks in ml/agebert...
20090610T122134.218> nnimap: Setting marks in ml/agebert...done

-- 
     My software never has bugs. It just develops random features.

bug#3521: 23.0.94; process-send-region errors / bug#2272 strikes again

[David Engster]

Tassilo Horn <thorn@fastmail.fm> writes:
> Evaluating this code once again triggers an error (I already reported it
> in bug 2272 some times ago, and it was fixed and the bug closed):

[...]

> Here's the backtrace:

[...]

> This time I cannot reproduce this easily with emacs -Q, but with my
> usual config it always happens.  But the test case above uses only very
> low-level functions which shouldn't be influenced by any customization
> anyway, right?  At none of them is redefined or adviced by me...

I can confirm this bug, and I think I've found the culprit:
'display-time'. At least that one always triggers the bug for me. It
seems this happens when the modeline gets updated (i.e. at the full
minute).

Therefore, use this recipe to reproduce the bug:

* emacs -Q
* M-x display-time RET
* Evaluate the code Tassilo posted
* The error will appear at the next full minute.

Tassilo, if you do not have (display-time) in your .emacs, look for
other stuff that could update the modeline in the background.

-David

bug#3521: 23.0.94; process-send-region errors / bug#2272 strikes again

[Tassilo Horn]

David Engster <deng@randomsample.de> writes:

Hi David,

> Therefore, use this recipe to reproduce the bug:
>
> * emacs -Q
> * M-x display-time RET
> * Evaluate the code Tassilo posted
> * The error will appear at the next full minute.
>
> Tassilo, if you do not have (display-time) in your .emacs, look for
> other stuff that could update the modeline in the background.

I don't use it, but for example rcirc-track-minor-mode updates the
mode-line whenever someone talks in an IRC channel I'm visiting.  This
happens quite ofter (< 1 min).

Bye,
Tassilo

bug#3521: 23.0.94; process-send-region errors / bug#2272 strikes again

[Tassilo Horn]

Tassilo Horn <thorn@fastmail.fm> writes:

>> Therefore, use this recipe to reproduce the bug:
>>
>> * emacs -Q
>> * M-x display-time RET
>> * Evaluate the code Tassilo posted
>> * The error will appear at the next full minute.
>>
>> Tassilo, if you do not have (display-time) in your .emacs, look for
>> other stuff that could update the modeline in the background.
>
> I don't use it, but for example rcirc-track-minor-mode updates the
> mode-line whenever someone talks in an IRC channel I'm visiting.  This
> happens quite ofter (< 1 min).

It seems not every update of the mode line triggers the error, but this
snippet errors after about 5-10 seconds here (with emacs -Q):

--8<---------------cut here---------------start------------->8---
(progn
  (run-with-timer 1 1 'force-mode-line-update)
  (setq proctest
	(start-process "cat" (get-buffer-create "cat") "/bin/cat"))
  (with-temp-buffer
    (dotimes (dummy 999999)
      (insert
       (concat (number-to-string (random))
	       (number-to-string (random))
	       (number-to-string (random))
	       (number-to-string (random))
	       "\n")))
    (process-send-region proctest (point-min) (point-max)))
  (delete-process proctest))
--8<---------------cut here---------------end--------------->8---

Bye,
Tassilo