mythtv crashes on exit with SIGSEGV in QApplication::~QApplication()

[Hokky]

Binary package hint: mythtv

mythcommflag crashed while flagging a recording.
The computer was not being used when it crashed.

ProblemType: Crash
Architecture: i386
Date: Thu Mar 8 21:34:07 2007
Disassembly: 0xb4f44f0c:
DistroRelease: Ubuntu 7.04
ExecutablePath: /usr/bin/mythcommflag
Package: mythtv-backend 0.20-svn20070122-0.0ubuntu2
PackageArchitecture: i386
ProcCmdline: /usr/bin/mythcommflag -j 255 -V 3
ProcCwd: /
ProcEnviron: PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
Signal: 11
SourcePackage: mythtv
Stacktrace:
 #0 0xb4f44f0c in ?? ()
 #1 0xb6121a9c in QApplication::~QApplication () from /usr/lib/libqt-mt.so.3
 #2 0x0805cad8 in ?? ()
 #3 0xb59d3ebc in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
 #4 0x08050961 in ?? ()
StacktraceTop:
 ?? ()
 QApplication::~QApplication () from /usr/lib/libqt-mt.so.3
 ?? ()
 __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
 ?? ()
Uname: Linux Hokky 2.6.20-9-generic #2 SMP Mon Feb 26 03:01:44 UTC 2007 i686 GNU/Linux
UserGroups: audio cdrom video

[Timothy Smith (tas50)]

Just happened to me with an up to date Feisty machine. Quit the app and it crashed.

[Mario Limonciello (superm1)]

Is this s a known good stream this occurred on, or something with possible
digital corruption?

On 3/8/07, Timothy Smith <email address hidden> wrote:
>
> Just happened to me with an up to date Feisty machine. Quit the app and
> it crashed.
>
> --
> [apport] mythcommflag crashed with SIGSEGV in
> QApplication::~QApplication()
> https://launchpad.net/bugs/90710
>

--
Mario Limonciello
<email address hidden>

[Jovaro (bug-jovaro)]

It started happening to me as well. I think it started about a week ago. I have been running feisty for quite a while and mythtv was working just fine.

I can't remember seeing a mythtv update so maybe an update of something else causes there crashes?

[Hokky (hakon)]

All the recordings that are flagged get 139 breaks. There should only be about 2-3 of them. I'll be happy to provide any other useful information. I've been running Feisty for a while without any problems. This occurred around installing the Herd 5 updates, but not sure exactly when.

[Hokky (hakon)]

I've found a segmentation fault in the mythbackend.log:

-----------
2007-03-10 19:30:25.320 AFD: Opened codec 0x8151280, id(MPEG2VIDEO) type(Video)
2007-03-10 19:30:25.367 AFD: Opened codec 0x8151680, id(MP2) type(Audio)
Segmentation fault (core dumped)
2007-03-10 19:56:30.651 JobQueue: Commercial Flagging Finished, 139 break(s) found.
-----------

I'll include the latest logfile. Promise not to laugh at my girlfriends Dr. Phil recordings :)

[Kees Cook (kees)]

This looks like the crash is happening in libqt, actually, and on program shutdown. All the myth crashes during QApplication::~QApplication are hitting this code:

#0 0xb4f44f0c in ?? ()
#1 0xb6121a9c in ~QApplication (this=0xbfb90654)
    at kernel/qapplication.cpp:1035

    if ( postRList ) {
    QVFuncList::Iterator it = postRList->begin();
    while ( it != postRList->end() ) { // call post routines
        (**it)(); // LINE 1035
        postRList->remove( it );
        it = postRList->begin();
    }
    delete postRList;
    postRList = 0;
    }

Given that 0xb4f44f0c is outside the mapped memory area, that would imply something has gone very wrong. :) Another odd thing is that I can't find any place in the myth programs where qAddPostRoutine is called. I'm unclear if some myth library is causing corruption inside QApplication, or if QApplication is the source of the problem.

Whatever the case, it doesn't seem specific to mythcommflag.

[Kees Cook (kees)]

Others seem to agree: this is a qt problem with 3.3.8:

http://www.gossamer-threads.com/lists/mythtv/dev/257269?page=last

[Kees Cook (kees)]

Extracted from SuSE's qt3 update from the linked bug report.

[Kees Cook (kees)]

Confirmed to fix the crashes seen by the myth* applications.

[Brad Needham (fishrcynic)]

installed wine - (force install onto amd64 with a few additional
libraries as per wineHQ

interestingly mythtv frontend now closes without error

Kees Cook wrote:
> ** Summary changed:
>
> - [apport] mythtv crashed with SIGSEGV in QApplication::~QApplication()
> + mythtv crashes on exit with SIGSEGV in QApplication::~QApplication()
>
>

[Kees Cook (kees)]

 qt-x11-free (3:3.3.8-0ubuntu2) feisty; urgency=low
 .
   * debian/patches/kubuntu_05_mysql_shutdown_fix.dpatch: from Dirk,
     fix mysql to not use postProc for shutdown (LP: #90710).

[Kees Cook (kees)]

Added a (rejected) mythtv task so that this bug shows up in mythtv searches, even though it's a (now fixed) bug in qt-x11-free.