[apport] GNOME Terminal Unicode SIGSEGV

[Michael B. Trausch]

Binary package hint: gnome-terminal

In Ubuntu Feisty, when editing a file in emacs (started with “emacs -nw filename”), I attempted to enter a Unicode character using GNOME’s Unicode character entry method—pressing C-S-u and the Unicode code point (in this case, I was attempting to input character 201c, the English open double quote character. I found the bug accidentally (Emacs doesn’t support entry of all Unicode characters like this in the terminal, so my workaround was to create a shortcut in Emacs, “C-c u”, for Unicode character entry; I mistyped and discovered the bug).

Apport has attached numerous items to this bug report. If there is any additionally required information, please let me know.

ProblemType: Crash
Architecture: i386
Date: Sat Mar 3 13:44:52 2007
DistroRelease: Ubuntu 7.04
ExecutablePath: /usr/bin/gnome-terminal
Package: gnome-terminal 2.17.92-0ubuntu1
ProcCmdline: gnome-terminal
ProcCwd: /home/mbt
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Signal: 11
SourcePackage: gnome-terminal
StacktraceTop:
 ?? () from /lib/tls/i686/cmov/libc.so.6
 ?? () from /usr/lib/libfreetype.so.6
 ?? ()
 ?? ()
 ?? () from /lib/tls/i686/cmov/libc.so.6
Uname: Linux pepper 2.6.20-9-generic #2 SMP Mon Feb 26 03:01:44 UTC 2007 i686 GNU/Linux
UserGroups: adm admin audio cdrom dialout dip floppy lpadmin netdev plugdev powerdev scanner video

[Sebastien Bacher (seb128)]

Thanks for your bug report. The crash looks like a memory corruption. Could you try to get a valgrind log for it? (you can follow the instructions from https://wiki.ubuntu.com/Valgrind for that)

[Michael B. Trausch (mtrausch)]

I am working on it but…

… When I am running it in Valgrind, it seems that it will let me type the Unicode characters! If I stop running it under Valgrind, the problem comes back, though… what are the side effects of Valgrind on the target application? Are there supposed to be any?

[Michael B. Trausch (mtrausch)]

Arrgh. It would seem that Valgrind is not the thing that changed… it seems that it is working now, so one of the updates fixed it.

I am going to keep this open for another few days and see if I run into the problem again. For now, though, my hands hurt from beating against the keyboard trying every combo I could think of. :-) I even wrote a Python script to output tons of Unicode chars to make it crash, and it didn’t. Probably has something to do with the 180 or so updates from today and yesterday.

[Michael B. Trausch (mtrausch)]

Hrm. I just ran into the problem again. So, I fired it up again under Valgrind as per the directions above, and the problem goes away. Take away Valgrind, and it is back (somewhat randomly).

I am attaching a single log from Valgrind, though I don’t know if it will be helpful because it did not actually crash.

[Johan Kiviniemi (ion)]

Also xfce4-terminal suffers from the same problem. For the apport files from a xfce4-terminal crash, see bug #92521.

Adding libvte9 to the Affects list, as it provides the terminal widget both gnome-terminal and xfce4-terminal use.

[Sebastien Bacher (seb128)]

Michael, thank you for your work on that, the log shows a libvte bug, you don't have libvte9-dbgsym installed though, could you try to get one with it?

[Michael B. Trausch (mtrausch)]

Where do I get that?

mbt@pepper:~$ apt-cache search libvte9
libvte9 - Terminal emulator widget for GTK+ 2.0 - runtime files
mbt@pepper:~$

[Sebastien Bacher (seb128)]

how to install a dbgsym is explained on https://wiki.ubuntu.com/DebuggingProgramCrash

[Michael B. Trausch (mtrausch)]

Okay, I have installed that package and again run the Valgrind process. Something else, and I do not know if this would be related or not (and it is merely cosmetic) is that the font rendering quality seems to have recently been diminished. Again, don’t know if it is related or not, but just mentioning it in case it is.

Attaching new Valgrind log, as well as the script that I ran to automate the process of at least displaying tons of Unicode characters. I haven’t figured out how to write a script to play keyboard with the terminal app and try to hit it with all of the Unicode characters, though that would be quite useful (and save my fingers a lot of work :-)).

[Johan Kiviniemi (ion)]

This seems to fix the problem.

vte (1:0.16.0-0ubuntu3) feisty; urgency=low

  * debian/patches/95_segfault_with_unicode_input.patch:
    - Fix segfault when typing an Unicode character with Ctrl-Shift-Unnnn.
      Thanks to Chris Wilson for the patch, which was downloaded from
      http://bugzilla.gnome.org/show_bug.cgi?id=418588 (LP: #89524)

[Michael B. Trausch (mtrausch)]

Thanks for the patch! I have applied it against the source code and built my own package for it and installed it, and it seems to be working, for now at least. Presumably, I should know within a couple of hours if there is still a problem… I use Unicode extensively within the terminal. :-)

[Johan Kiviniemi (ion)]

As a different -ubuntu3 was released, here's a new debdiff.

[Sebastien Bacher (seb128)]

fixed upstream now

[Sebastien Bacher (seb128)]

Thank you for the work on that Johan. This upload fixes the bug:

 vte (1:0.16.0-0ubuntu4) feisty; urgency=low
 .
   * debian/patches/71_from_bugzilla_fix_refresh_on_workspace_change.patch:
     - patch from bugzilla, fix refresh bug when changing workspace
       (Ubuntu: #92405)
   * debian/patches/90_from_svn_fix_double_text_rendering.patch:
     - patch from SVN, fix double text rendering (Ubuntu: #93481)
 .
   [ Johan Kiviniemi ]
   * debian/patches/95_segfault_with_unicode_input.patch:
     - Fix segfault when typing a Unicode character with Ctrl-Shift-Unnnn.
       Thanks to Chris Wilson for the patch, which was downloaded from
       http://bugzilla.gnome.org/show_bug.cgi?id=418588 (LP: #89524)