Application: plasma-desktop (0.4)
KDE Platform Version: 4.7.3 (4.7.3)
Qt Version: 4.7.4
Operating System: Linux 3.0.0-14-generic x86_64
Distribution: Ubuntu 11.10

-- Information about the crash:
- What I was doing when the application crashed:
I hoovered with the mouse over the taskbar and the crush - report bug window open. The taskbar disappeared for a second and then reappeared.

The crash can be reproduced some of the time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0x7ffbde0187c0 (LWP 1646))]

Thread 4 (Thread 0x7ffbb8036700 (LWP 1651)):
#0  0x00007ffbd29951fd in __pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:52
#1  __pthread_mutex_unlock (mutex=0x2cc9088) at pthread_mutex_unlock.c:290
#2  0x00007ffbd1e84f9a in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffbd1e85429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ffbdaaebf3e in QEventDispatcherGlib::processEvents (this=0x2cc8aa0, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#5  0x00007ffbdaabfcf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007ffbdaabfef7 in QEventLoop::exec (this=0x7ffbb8035cd0, flags=...) at kernel/qeventloop.cpp:201
#7  0x00007ffbda9d727f in QThread::exec (this=<optimized out>) at thread/qthread.cpp:498
#8  0x00007ffbdaaa2cbf in QInotifyFileSystemWatcherEngine::run (this=0x2b84e80) at io/qfilesystemwatcher_inotify.cpp:248
#9  0x00007ffbda9d9d05 in QThreadPrivate::start (arg=0x2b84e80) at thread/qthread_unix.cpp:331
#10 0x00007ffbcf19e56c in ?? () from /usr/lib/nvidia-current/libGL.so.1
#11 0x00007ffbd2991efc in start_thread (arg=0x7ffbb8036700) at pthread_create.c:304
#12 0x00007ffbdd90689d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#13 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7ffbb5391700 (LWP 1700)):
#0  0x00007ffbdd8fa773 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007ffbd1e84f68 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffbd1e85429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffbdaaebf3e in QEventDispatcherGlib::processEvents (this=0x31ff450, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#4  0x00007ffbdaabfcf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007ffbdaabfef7 in QEventLoop::exec (this=0x7ffbb5390cd0, flags=...) at kernel/qeventloop.cpp:201
#6  0x00007ffbda9d727f in QThread::exec (this=<optimized out>) at thread/qthread.cpp:498
#7  0x00007ffbdaaa2cbf in QInotifyFileSystemWatcherEngine::run (this=0x3204f40) at io/qfilesystemwatcher_inotify.cpp:248
#8  0x00007ffbda9d9d05 in QThreadPrivate::start (arg=0x3204f40) at thread/qthread_unix.cpp:331
#9  0x00007ffbcf19e56c in ?? () from /usr/lib/nvidia-current/libGL.so.1
#10 0x00007ffbd2991efc in start_thread (arg=0x7ffbb5391700) at pthread_create.c:304
#11 0x00007ffbdd90689d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7ffbad9d6700 (LWP 1706)):
#0  0x00007ffbd29951fd in __pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:52
#1  __pthread_mutex_unlock (mutex=0x354bd68) at pthread_mutex_unlock.c:290
#2  0x00007ffbd1e84900 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffbd1e85258 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ffbd1e85792 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ffbae4b4516 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6  0x00007ffbd1eaa2b6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#7  0x00007ffbcf19e56c in ?? () from /usr/lib/nvidia-current/libGL.so.1
#8  0x00007ffbd2991efc in start_thread (arg=0x7ffbad9d6700) at pthread_create.c:304
#9  0x00007ffbdd90689d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#10 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7ffbde0187c0 (LWP 1646)):
[KCrash Handler]
#6  isNull (this=0x0) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:568
#7  operator! (this=0x0) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:574
#8  TaskManager::TaskItem::task (this=0x31327c0) at ../../../libs/taskmanager/taskitem.cpp:113
#9  0x00007ffbc1743112 in WindowTaskItem::publishIconGeometry (this=0x247b710) at ../../../../../plasma/desktop/applets/tasks/windowtaskitem.cpp:120
#10 0x00007ffbc1751b7c in AbstractTaskItem::timerEvent (this=0x247b710, event=<optimized out>) at ../../../../../plasma/desktop/applets/tasks/abstracttaskitem.cpp:439
#11 0x00007ffbdaad7789 in QObject::event (this=0x247b710, e=<optimized out>) at kernel/qobject.cpp:1181
#12 0x00007ffbda48f89b in QGraphicsWidget::event (this=0x247b710, event=0x7fff0accdba0) at graphicsview/qgraphicswidget.cpp:1455
#13 0x00007ffbd9e71424 in notify_helper (e=0x7fff0accdba0, receiver=0x247b710, this=0x22d7350) at kernel/qapplication.cpp:4486
#14 QApplicationPrivate::notify_helper (this=0x22d7350, receiver=0x247b710, e=0x7fff0accdba0) at kernel/qapplication.cpp:4458
#15 0x00007ffbd9e76291 in QApplication::notify (this=0x22b88f0, receiver=0x247b710, e=0x7fff0accdba0) at kernel/qapplication.cpp:4365
#16 0x00007ffbdb76f126 in KApplication::notify (this=0x22b88f0, receiver=0x247b710, event=0x7fff0accdba0) at ../../kdeui/kernel/kapplication.cpp:311
#17 0x00007ffbdaac0afc in QCoreApplication::notifyInternal (this=0x22b88f0, receiver=0x247b710, event=0x7fff0accdba0) at kernel/qcoreapplication.cpp:787
#18 0x00007ffbdaaedd62 in sendEvent (event=0x7fff0accdba0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#19 QTimerInfoList::activateTimers (this=0x22d5f40) at kernel/qeventdispatcher_unix.cpp:603
#20 0x00007ffbdaaeb538 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:184
#21 idleTimerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:231
#22 0x00007ffbd1e84a5d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#23 0x00007ffbd1e85258 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#24 0x00007ffbd1e85429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#25 0x00007ffbdaaebed6 in QEventDispatcherGlib::processEvents (this=0x221df40, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#26 0x00007ffbd9f1907e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=<optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#27 0x00007ffbdaabfcf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#28 0x00007ffbdaabfef7 in QEventLoop::exec (this=0x7fff0accde30, flags=...) at kernel/qeventloop.cpp:201
#29 0x00007ffbdaac4789 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1064
#30 0x00007ffbddc051a3 in kdemain (argc=1, argv=0x7fff0acce218) at ../../../../plasma/desktop/shell/main.cpp:120
#31 0x00007ffbdd84630d in __libc_start_main (main=0x400640 <main(int, char**)>, argc=1, ubp_av=0x7fff0acce218, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff0acce208) at libc-start.c:226
#32 0x0000000000400671 in _start ()

Possible duplicates by query: bug 290372, bug 290364, bug 290336, bug 290300, bug 290291.

Reported using DrKonqi