kmix crash in MDWSlider::update() when last.fm plays next title

[Christian Heimes]

Ubuntu: 12.04 devel
platform: AMD64
kmix: 4:4.8.1-0ubuntu1
lastfm: 1:1.5.4.27091+dfsg-6ubuntu2

Everytime last.fm plays the next song, kmix crashs with a segfault. I'm able to reproduce the bug everytime I skip to the next title.

Application: KMix (kmix), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f52e6906780 (LWP 28704))]

Thread 3 (Thread 0x7f52c6601700 (LWP 28705)):
#0 0x00007fffb2bff8de in ?? ()
#1 0x00007f52dc93415d in __GI_clock_gettime (clock_id=<optimized out>, tp=<optimized out>) at ../sysdeps/unix/clock_gettime.c:116
#2 0x00007f52e2e7d654 in do_gettime (frac=0x7f52c6600b98, sec=0x7f52c6600b90) at tools/qelapsedtimer_unix.cpp:123
#3 qt_gettime () at tools/qelapsedtimer_unix.cpp:140
#4 0x00007f52e2f551fd in QTimerInfoList::updateCurrentTime (this=0x7f52c0002860) at kernel/qeventdispatcher_unix.cpp:343
#5 0x00007f52e2f55533 in QTimerInfoList::timerWait (this=0x7f52c0002860, tm=...) at kernel/qeventdispatcher_unix.cpp:450
#6 0x00007f52e2f53fec in timerSourcePrepareHelper (src=<optimized out>, timeout=0x7f52c6600c6c) at kernel/qeventdispatcher_glib.cpp:136
#7 0x00007f52e2f54095 in timerSourcePrepare (source=<optimized out>, timeout=<optimized out>) at kernel/qeventdispatcher_glib.cpp:169
#8 0x00007f52dbfd880e in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#9 0x00007f52dbfd900b in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#10 0x00007f52dbfd9214 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#11 0x00007f52e2f54a96 in QEventDispatcherGlib::processEvents (this=0x7f52c00008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#12 0x00007f52e2f242f2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#13 0x00007f52e2f24547 in QEventLoop::exec (this=0x7f52c6600dd0, flags=...) at kernel/qeventloop.cpp:204
#14 0x00007f52e2e23f97 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#15 0x00007f52e2f0406f in QInotifyFileSystemWatcherEngine::run (this=0x14c99a0) at io/qfilesystemwatcher_inotify.cpp:248
#16 0x00007f52e2e26fbb in QThreadPrivate::start (arg=0x14c99a0) at thread/qthread_unix.cpp:298
#17 0x00007f52dcb3fe9a in start_thread (arg=0x7f52c6601700) at pthread_create.c:308
#18 0x00007f52e61da4bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#19 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f52c5bf5700 (LWP 28706)):
#0 0x00007f52dbfd9078 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1 0x00007f52dbfd9214 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007f52e2f54a96 in QEventDispatcherGlib::processEvents (this=0x7f52b40008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#3 0x00007f52e2f242f2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#4 0x00007f52e2f24547 in QEventLoop::exec (this=0x7f52c5bf4dd0, flags=...) at kernel/qeventloop.cpp:204
#5 0x00007f52e2e23f97 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#6 0x00007f52e2f0406f in QInotifyFileSystemWatcherEngine::run (this=0x1451080) at io/qfilesystemwatcher_inotify.cpp:248
#7 0x00007f52e2e26fbb in QThreadPrivate::start (arg=0x1451080) at thread/qthread_unix.cpp:298
#8 0x00007f52dcb3fe9a in start_thread (arg=0x7f52c5bf5700) at pthread_create.c:308
#9 0x00007f52e61da4bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#10 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f52e6906780 (LWP 28704)):
[KCrash Handler]
#6 0x00007f52e64fae23 in MDWSlider::update (this=0x1613830) at ../../kmix/gui/mdwslider.cpp:1001
#7 0x00007f52e64f664b in ViewDockAreaPopup::refreshVolumeLevels (this=<optimized out>) at ../../kmix/gui/viewdockareapopup.cpp:168
#8 0x00007f52e2f398f1 in QMetaObject::activate (sender=0x1582c10, m=<optimized out>, local_signal_index=<optimized out>, argv=0x0) at kernel/qobject.cpp:3547
#9 0x00007f52e2f398f1 in QMetaObject::activate (sender=0x1572ab0, m=<optimized out>, local_signal_index=<optimized out>, argv=0x0) at kernel/qobject.cpp:3547
#10 0x00007f52e64cfb0c in Mixer_Backend::readSetFromHW (this=0x1572ab0) at ../../kmix/backends/mixer_backend.cpp:155
#11 0x00007f52e64dfdf5 in sink_cb (c=<optimized out>, i=<optimized out>, eol=<optimized out>) at ../../kmix/backends/mixer_pulse.cpp:191
#12 0x00007f52e48b7944 in ?? () from /usr/lib/x86_64-linux-gnu/libpulse.so.0
#13 0x00007f52dc4f7693 in ?? () from /usr/lib/x86_64-linux-gnu/libpulsecommon-1.1.so
#14 0x00007f52dc4f7a03 in pa_pdispatch_run () from /usr/lib/x86_64-linux-gnu/libpulsecommon-1.1.so
#15 0x00007f52e48adbdd in ?? () from /usr/lib/x86_64-linux-gnu/libpulse.so.0
#16 0x00007f52dc4fc2a9 in ?? () from /usr/lib/x86_64-linux-gnu/libpulsecommon-1.1.so
#17 0x00007f52e469bab3 in ?? () from /usr/lib/x86_64-linux-gnu/libpulse-mainloop-glib.so.0
#18 0x00007f52dbfd8d8a in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f52dbfd9150 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f52dbfd9214 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007f52e2f54a2f in QEventDispatcherGlib::processEvents (this=0x1226ad0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#22 0x00007f52e3c3fb1e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#23 0x00007f52e2f242f2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#24 0x00007f52e2f24547 in QEventLoop::exec (this=0x7fffb2bab0d0, flags=...) at kernel/qeventloop.cpp:204
#25 0x00007f52e2f295d7 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#26 0x00007f52e64e73e2 in kdemain (argc=5, argv=0x7fffb2bab658) at ../../kmix/apps/main.cpp:76
#27 0x00007f52e610976d in __libc_start_main (main=0x400630 <main(int, char**)>, argc=5, ubp_av=0x7fffb2bab658, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffb2bab648) at libc-start.c:226
#28 0x0000000000400661 in _start ()

[Christian Heimes (heimes)]

I'm no longer able to reproduce the bug. A recent update may have fixed the segfault. I'll keep you posted.