GNU bug report logs - #11919
24.1; term-emulate-term does not process bash's Ctrl-Z signal of directory name when an AnSi message is present

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 11919 in the body.
You can then email your comments to 11919 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Michael Hoffman <b3i4old02 <at> sneakemail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 24.1; term-emulate-term does not process bash's Ctrl-Z signal of
	directory name when an AnSi message is present
Date: Wed, 11 Jul 2012 17:45:16 -0700

This bug report will be sent to the Bug-GNU-Emacs mailing list
and the GNU bug tracker at debbugs.gnu.org.  Please check that
the From: line contains a valid email address.  After a delay of up
to one day, you should receive an acknowledgement at that address.

Please write in English if possible, as the Emacs maintainers
usually do not have translators for other languages.

Please describe exactly what actions triggered the bug, and
the precise symptoms of the bug.  If you can, give a recipe
starting from `emacs -Q':

I have GNU bash, version 4.1.2(1). When I do this:

1) emacs -Q
2) M-x ansi-term RET /bin/bash RET
3) PS1='\033AnSiTu x\012$ ' RET

From then on, every prompt will be preceded by a Ctrl-Z character and
the working directory. This is because recent versions of bash
try to figure out whether they are running under emacs, and if they
are, output Ctrl-Z and the working directory before the PS1 prompt.
term-emulate-terminal normally eliminates such garbage, but not when
it has also processed an AnSi message. The elimination only happens
when the following conditions are true:

(and (eq char ?\032)
     (not handled-ansi-message))

Suggested fix: eliminate the "(not handled-ansi-message)" form.

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'.
For information about debugging Emacs, please read the file
/net/gs/vol3/software/modules-sw/emacs/24.1/Linux/RHEL6/x86_64/share/emacs/24.1/etc/DEBUG.


In GNU Emacs 24.1.2 (x86_64-unknown-linux-gnu, GTK+ Version 2.18.9)
 of 2012-06-21 on rhel6-x64.grid.gs.washington.edu
Windowing system distributor `Red Hat, Inc.', version 11.0.11004000
Configured using:
 `configure '--without-gif' '--with-x' '--with-x-toolkit=gtk'
 '--prefix=/net/gs/vol3/software/modules-sw/emacs/24.1/Linux/RHEL6/x86_64'
 'LDFLAGS=-L/net/gs/vol3/software/modules-sw/boost/1.45.0/Linux/RHEL6/x86_64/lib/
 -L/net/gs/vol3/software/modules-sw/R/2.9.0/Linux/RHEL6/x86_64/lib/'
 'CPPFLAGS=-I/net/gs/vol3/software/modules-sw/boost/1.45.0/Linux/RHEL6/x86_64/include/
 -I/net/gs/vol3/software/modules-sw/R/2.9.0/Linux/RHEL6/x86_64/include/''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: en_US
  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: iso-latin-1-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e p o r t - b <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
goto-history-element: Beginning of history; no preceding item
goto-history-element: End of history; no default available

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail regexp-opt rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils time-date tooltip ediff-hook
vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image
fringe lisp-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 loaddefs button faces cus-face files text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process dynamic-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Message #8 received at submit <at> debbugs.gnu.org (full text, mbox):

From: "Michael Hoffman" <gmane3-hoffman <at> snkmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: Re: bug#11919: 24.1; term-emulate-term does not process bash's
 Ctrl-Z signal of directory name when an AnSi message is present
Date: Mon, 23 Jan 2017 12:54:10 -0500

On 07/11/2012 08:45 PM, Michael Hoffman wrote:

> 1) emacs -Q
> 2) M-x ansi-term RET /bin/bash RET
> 3) PS1='\033AnSiTu x\012$ ' RET
>
>  From then on, every prompt will be preceded by a Ctrl-Z character and
> the working directory. This is because recent versions of bash
> try to figure out whether they are running under emacs, and if they
> are, output Ctrl-Z and the working directory before the PS1 prompt.
> term-emulate-terminal normally eliminates such garbage, but not when
> it has also processed an AnSi message. The elimination only happens
> when the following conditions are true:
>
> (and (eq char ?\032)
>       (not handled-ansi-message))
>
> Suggested fix: eliminate the "(not handled-ansi-message)" form.

I have located the original commit that added the `handled-ansi-message` 
behavior: 
https://github.com/emacs-mirror/emacs/commit/59be5828de98814b8aa32718bf2b6196db085db1

Eli Zaretskii added it to "Let term-handle-ansi-terminal-messages 
override what Bash says about its current directory."

In order to keep this behavior but not print garbage to the buffer: I 
would suggest that perhaps the call to `term-command-hook` is what 
should be conditioned on `(not handled-ansi-message)` and not the rest 
of the code in this branch which seems to remove the garbage.

Michael Hoffman

Message #11 received at 11919 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: "Michael Hoffman" <gmane3-hoffman <at> snkmail.com>
Cc: 11919 <at> debbugs.gnu.org
Subject: Re: bug#11919: 24.1;
 term-emulate-term does not process bash's Ctrl-Z signal of directory
 name when an AnSi message is present
Date: Mon, 23 Jan 2017 20:18:51 +0200

> From: "Michael Hoffman" <gmane3-hoffman <at> snkmail.com>
> Date: Mon, 23 Jan 2017 12:54:10 -0500
> 
> I have located the original commit that added the `handled-ansi-message` 
> behavior: 
> https://github.com/emacs-mirror/emacs/commit/59be5828de98814b8aa32718bf2b6196db085db1
> 
> Eli Zaretskii added it to "Let term-handle-ansi-terminal-messages 
> override what Bash says about its current directory."

I was just committing someone else's patch in that case.

See these messages in the archives for the reason why that change was
done:

  https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-11/msg00020.html
  https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-11/msg00103.html
  https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-12/msg00089.html

If you can propose changes that solve this issue without
re-introducing that one, please do.

Thanks.

Message #14 received at 11919 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: gmane3-hoffman <at> snkmail.com
Cc: 11919 <at> debbugs.gnu.org
Subject: Re: bug#11919: 24.1;
 term-emulate-term does not process bash's Ctrl-Z signal of directory
 name when an AnSi message is present
Date: Mon, 23 Jan 2017 20:30:23 +0200

> Date: Mon, 23 Jan 2017 20:18:51 +0200
> From: Eli Zaretskii <eliz <at> gnu.org>
> Cc: 11919 <at> debbugs.gnu.org
> 
> > From: "Michael Hoffman" <gmane3-hoffman <at> snkmail.com>
> > Date: Mon, 23 Jan 2017 12:54:10 -0500
> > 
> > I have located the original commit that added the `handled-ansi-message` 
> > behavior: 
> > https://github.com/emacs-mirror/emacs/commit/59be5828de98814b8aa32718bf2b6196db085db1
> > 
> > Eli Zaretskii added it to "Let term-handle-ansi-terminal-messages 
> > override what Bash says about its current directory."
> 
> I was just committing someone else's patch in that case.

Btw, in the ChangeLog file this change is attributed correctly:

  2005-12-16  Mark Plaksin  <happy <at> usg.edu>  (tiny change)

	  * term.el (term-emulate-terminal):
	  Let term-handle-ansi-terminal-messages override what Bash says about
	  its current directory.

Message #17 received at 11919 <at> debbugs.gnu.org (full text, mbox):

From: Michael Hoffman <hoffman <at> cantab.net>
To: "Eli Zaretskii eliz-at-gnu.org |gmane3-hoffman|"
 <0wdp3p2xrt <at> sneakemail.com>
Cc: 11919 <at> debbugs.gnu.org, Michael Hoffman <gmane3-hoffman <at> snkmail.com>
Subject: Re: bug#11919: 24.1; term-emulate-term does not process bash's Ctrl-Z
 signal of directory name when an AnSi message is present
Date: Mon, 23 Jan 2017 14:24:28 -0500

[Message part 1 (text/plain, inline)]

On Mon, Jan 23, 2017 at 1:18 PM, Eli Zaretskii eliz-at-gnu.org
|gmane3-hoffman| <0wdp3p2xrt <at> sneakemail.com> wrote:

> > From: "Michael Hoffman" <gmane3-hoffman <at> snkmail.com>
> > Date: Mon, 23 Jan 2017 12:54:10 -0500
> >
> > I have located the original commit that added the `handled-ansi-message`
> > behavior:
> > https://github.com/emacs-mirror/emacs/commit/59be5828de98814
> b8aa32718bf2b6196db085db1
> >
> > Eli Zaretskii added it to "Let term-handle-ansi-terminal-messages
> > override what Bash says about its current directory."
>
> I was just committing someone else's patch in that case.
>

Please accept my apologies.


> See these messages in the archives for the reason why that change was
> done:
>
>   https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-11
> /msg00020.html
>   https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-11
> /msg00103.html
>   https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-12
> /msg00089.html
>
> If you can propose changes that solve this issue without
> re-introducing that one, please do.
>

The below patch eliminates the garbage printing while maintaining the
behavior added in 2005 of having `handled-ansi-message` preventing any
updates to `default-directory` based on a \032 escape.

mhoffman <at> mhoffman2 ~/share/emacs/25.1/lisp
$ diff -u <(zcat term.el.gz) term.el
--- /dev/fd/63  2017-01-23 14:13:55.948963291 -0500
+++ term.el     2017-01-23 14:11:43.903830242 -0500
@@ -2869,15 +2869,16 @@
                         ((eq char ?\017))     ; Shift In - ignored
                         ((eq char ?\^G) ;; (terminfo: bel)
                          (beep t))
-                        ((and (eq char ?\032)
-                               (not handled-ansi-message))
+                        ((eq char ?\032)
                          (let ((end (string-match "\r?$" str i)))
                            (if end
-                               (funcall term-command-hook
-                                        (decode-coding-string
-                                         (prog1 (substring str (1+ i) end)
-                                           (setq i (match-end 0)))
-                                         locale-coding-system))
+                                (progn
+                                  (unless handled-ansi-message
+                                    (funcall term-command-hook
+                                             (decode-coding-string
+                                              (substring str (1+ i) end)
+                                              locale-coding-system)))
+                                  (setq i (match-end 0)))
                              (setq term-terminal-parameter (substring str
i))
                              (setq term-terminal-state 4)
                              (setq i str-length))))

====
ChangeLog:

2017-01-23  Michael Hoffman  <emacs-hoffman <at> sneakemail.com>

  * term.el (term-emulate-terminal): fix bug#11919:
  do not display ?\032 escape codes even when `handled-ansi-message` is true

[Message part 2 (text/html, inline)]

Message #22 received at 11919-done <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Michael Hoffman <hoffman <at> cantab.net>
Cc: 11919-done <at> debbugs.gnu.org, 0wdp3p2xrt <at> sneakemail.com,
 gmane3-hoffman <at> snkmail.com
Subject: Re: bug#11919: 24.1;
 term-emulate-term does not process bash's Ctrl-Z signal of directory
 name when an AnSi message is present
Date: Fri, 27 Jan 2017 11:30:46 +0200

> From: Michael Hoffman <hoffman <at> cantab.net>
> Date: Mon, 23 Jan 2017 14:24:28 -0500
> Cc: 11919 <at> debbugs.gnu.org, Michael Hoffman <gmane3-hoffman <at> snkmail.com>
> 
>  See these messages in the archives for the reason why that change was
>  done:
> 
>  https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-11/msg00020.html
>  https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-11/msg00103.html
>  https://lists.gnu.org/archive/html/emacs-pretest-bug/2005-12/msg00089.html
> 
>  If you can propose changes that solve this issue without
>  re-introducing that one, please do.
> 
> The below patch eliminates the garbage printing while maintaining the behavior added in 2005 of having
> `handled-ansi-message` preventing any updates to `default-directory` based on a \032 escape.

Thanks, I pushed this to the master branch, with a slight change due
to changes in the surrounding code since the version you were using.
Please test the master branch, if you can, and please reopen the bug
if some issues are left.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.