FVWM: Bugreport: fvwm crashes under Debian

[Dirk Thierbach]

Hello,

if this is the wrong place for bugreports, or if I should use the other
list, please tell me. I couldn't find anything on the homepage, but maybe
I overlooked it.

I updated fvwm to 1:2.6.5.ds-1 on Debian Sid (unstable), and now I
experience frequent crashes which dump me back to the xdm login screen.

They happen unpredicatbly when changing or deleting a tab in
iceweasel (which changes the title of the iceweasel window).

I've already disabled window titles in FvmwPager, using

*FvwmPager: SmallFont none

but no change so far. I cannot produce the crashes on purpose, but
they happen frequently enough, so I should be able to do testing.

The Xsession error log contains:

*** glibc detected *** /usr/bin/fvwm2: double free or corruption (out): 0xb71133f8 ***
======= Backtrace: =========
/lib/i386-linux-gnu/i686/cmov/libc.so.6(+0x70f01)[0xb7023f01]
/lib/i386-linux-gnu/i686/cmov/libc.so.6(+0x72768)[0xb7025768]
/lib/i386-linux-gnu/i686/cmov/libc.so.6(cfree+0x6d)[0xb702881d]
/usr/lib/i386-linux-gnu/libX11.so.6(XFreeStringList+0x2c)[0xb76338ec]
======= Memory map: ========
...
b70d6000-b71e0000 r-xp 00000000 08:15 328385 /usr/lib/i386-linux-gnu/libcairo.so.2.11200.2
...

apparently not on every crash, but often enough. It also contains

[fvwm][convert_charsets]: WARNING -
Invalid byte sequence during conversion from UTF-8 to ISO-8859-1

I'm not sure if that is related. I also upgraded a lot of librariries, so
maybe it's really a bug in one library, but it seems to be triggered by
fvwm, so I'm asking here first.

I'm using Zaphod mode with an Intel driver, and one screen is not connected
ATM, in case that matters.

Any ideas? If necessary, I can compile from CVS and bisect if anyone can point
me to an appropriate version range.

Thanks,

- Dirk

[Thomas Adam]

Post by Dirk Thierbach
I've already disabled window titles in FvmwPager, using
*FvwmPager: SmallFont none

This is naughty of you, since it's a red-herring. :P

Can you please try the CVS version (using branch-2_6 -- see:
http://fvwm.org/documentation/dev_cvs.php

Then compile FVWM with debug symbols (CFLAGS="-02 -g -ggdb") and get a
proper stack trace via gdb, please.

-- Thomas Adam

[Walter Alejandro Iglesias]

Post by Dirk Thierbach
Hello,
if this is the wrong place for bugreports, or if I should use the other
list, please tell me. I couldn't find anything on the homepage, but maybe
I overlooked it.
I updated fvwm to 1:2.6.5.ds-1 on Debian Sid (unstable), and now I
experience frequent crashes which dump me back to the xdm login screen.
They happen unpredicatbly when changing or deleting a tab in
iceweasel (which changes the title of the iceweasel window).

I remember having that problem with some version of firefox, not
only with FVWM but with fluxbox too. I read people on forums
complaining about the same problem with Xfce. I ignore which
version of firefox iceweasel sid package fork. Download the
latest firefox from mozilla site and try to reproduce the bug.
I think that it's some issue with hardware acceleration. You
could also try disabling that feature on Iceweasel (on Advanced
tag in Options uncheck "hardward accel...") if that version
already have it.

Walter