Application: plasma-desktop (0.4)
KDE Platform Version: 4.8.2 (4.8.2)
Qt Version: 4.8.1
Operating System: Linux 3.2.0-24-generic x86_64
Distribution: Ubuntu 12.04 LTS

-- Information about the crash:
- What I was doing when the application crashed:
I changed the height of the launch bar on a second screen. After a few changes, and increasing and decreasing the height (which worked fine), it crashed. This was reproducible, although it took a few more height changes the second time.

- Custom settings of the application:
I changed the window list on the launch bar to show up to 3 lines of windows. It used to be 2 before. I do not assume this is related, but this is the last change I made before trying to change the size.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma-Desktop-Umgebung (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f22395de780 (LWP 2110))]

Thread 5 (Thread 0x7f2216438700 (LWP 2112)):
#0  0x00007f2238ea7b03 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f222d064ff6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f222d065124 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f2236085426 in QEventDispatcherGlib::processEvents (this=0x7f22100008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#4  0x00007f2236054c82 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007f2236054ed7 in QEventLoop::exec (this=0x7f2216437dd0, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007f2235f53fa7 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#7  0x00007f22360349ff in QInotifyFileSystemWatcherEngine::run (this=0x833f20) at io/qfilesystemwatcher_inotify.cpp:248
#8  0x00007f2235f56fcb in QThreadPrivate::start (arg=0x833f20) at thread/qthread_unix.cpp:298
#9  0x00007f222d969e9a in start_thread (arg=0x7f2216438700) at pthread_create.c:308
#10 0x00007f2238eb34bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 4 (Thread 0x7f220eaa1700 (LWP 2113)):
#0  __libc_enable_asynccancel () at ../nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S:66
#1  0x00007f2238ea7ae8 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:85
#2  0x00007f222d064ff6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f222d065124 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f2236085426 in QEventDispatcherGlib::processEvents (this=0x7f22080008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#5  0x00007f2236054c82 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007f2236054ed7 in QEventLoop::exec (this=0x7f220eaa0dd0, flags=...) at kernel/qeventloop.cpp:204
#7  0x00007f2235f53fa7 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:501
#8  0x00007f22360349ff in QInotifyFileSystemWatcherEngine::run (this=0x128f4c0) at io/qfilesystemwatcher_inotify.cpp:248
#9  0x00007f2235f56fcb in QThreadPrivate::start (arg=0x128f4c0) at thread/qthread_unix.cpp:298
#10 0x00007f222d969e9a in start_thread (arg=0x7f220eaa1700) at pthread_create.c:308
#11 0x00007f2238eb34bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7f22077fe700 (LWP 2116)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f2232e39222 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#2  0x00007f2232e39259 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#3  0x00007f222d969e9a in start_thread (arg=0x7f22077fe700) at pthread_create.c:308
#4  0x00007f2238eb34bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f21fffff700 (LWP 2121)):
#0  0x00007f2238ea7b03 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f222d064ff6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f222d06545a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f2204fd92c6 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007f222d0869a5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f222d969e9a in start_thread (arg=0x7f21fffff700) at pthread_create.c:308
#6  0x00007f2238eb34bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f22395de780 (LWP 2110)):
[KCrash Handler]
#6  operator== (value=0, this=0x650064002f0071) at /usr/include/qt4/QtCore/qbasicatomic.h:70
#7  data (this=0x2311bd8) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:587
#8  AbstractTaskItem::abstractItem (this=0x2311b70) at ../../../../../plasma/desktop/applets/tasks/abstracttaskitem.cpp:1217
#9  0x00007f221cd28530 in TaskItemLayout::size (this=<optimized out>) at ../../../../../plasma/desktop/applets/tasks/taskitemlayout.cpp:167
#10 0x00007f221cd28573 in TaskItemLayout::size (this=<optimized out>) at ../../../../../plasma/desktop/applets/tasks/taskitemlayout.cpp:183
#11 0x00007f221cd29032 in TaskItemLayout::gridLayoutSize (this=0x1ade2a0) at ../../../../../plasma/desktop/applets/tasks/taskitemlayout.cpp:256
#12 0x00007f221cd290cd in TaskItemLayout::layoutItems (this=0x1ade2a0) at ../../../../../plasma/desktop/applets/tasks/taskitemlayout.cpp:281
#13 0x00007f221cd325cb in TaskGroupItem::constraintsChanged (this=0x1ae0430, constraints=...) at ../../../../../plasma/desktop/applets/tasks/taskgroupitem.cpp:869
#14 0x00007f221cd35ed4 in qt_static_metacall (_a=<optimized out>, _id=<optimized out>, _o=<optimized out>, _c=<optimized out>) at ./taskgroupitem.moc:101
#15 TaskGroupItem::qt_static_metacall (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at ./taskgroupitem.moc:81
#16 0x00007f223606a281 in QMetaObject::activate (sender=0xbf7610, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fffb74bc510) at kernel/qobject.cpp:3547
#17 0x00007f221cd259f2 in Tasks::constraintsChanged (this=<optimized out>, _t1=...) at ./tasks.moc:123
#18 0x00007f221cd25a53 in Tasks::constraintsEvent (this=0xbf7610, constraints=...) at ../../../../../plasma/desktop/applets/tasks/tasks.cpp:267
#19 0x00007f22389a1afc in Plasma::Applet::flushPendingConstraintsEvents (this=0xbf7610) at ../../plasma/applet.cpp:1365
#20 0x00007f22389a286d in Plasma::Applet::timerEvent (this=0xbf7610, event=<optimized out>) at ../../plasma/applet.cpp:2562
#21 0x00007f223606f179 in QObject::event (this=0xbf7610, e=<optimized out>) at kernel/qobject.cpp:1157
#22 0x00007f2235a1563b in QGraphicsWidget::event (this=0xbf7610, event=0x7fffb74bcec0) at graphicsview/qgraphicswidget.cpp:1461
#23 0x00007f22353d8894 in notify_helper (e=0x7fffb74bcec0, receiver=0xbf7610, this=0x6e1910) at kernel/qapplication.cpp:4559
#24 QApplicationPrivate::notify_helper (this=0x6e1910, receiver=0xbf7610, e=0x7fffb74bcec0) at kernel/qapplication.cpp:4531
#25 0x00007f22353dd713 in QApplication::notify (this=0x6cea60, receiver=0xbf7610, e=0x7fffb74bcec0) at kernel/qapplication.cpp:4420
#26 0x00007f2236d32b46 in KApplication::notify (this=0x6cea60, receiver=0xbf7610, event=0x7fffb74bcec0) at ../../kdeui/kernel/kapplication.cpp:311
#27 0x00007f2236055e9c in QCoreApplication::notifyInternal (this=0x6cea60, receiver=0xbf7610, event=0x7fffb74bcec0) at kernel/qcoreapplication.cpp:876
#28 0x00007f22360871f2 in sendEvent (event=0x7fffb74bcec0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#29 QTimerInfoList::activateTimers (this=0x6e9b00) at kernel/qeventdispatcher_unix.cpp:611
#30 0x00007f2236084c0d in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:186
#31 timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:180
#32 0x00007f222d064c9a in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#33 0x00007f222d065060 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#34 0x00007f222d065124 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#35 0x00007f22360853bf in QEventDispatcherGlib::processEvents (this=0x664ad0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#36 0x00007f2235480d5e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#37 0x00007f2236054c82 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#38 0x00007f2236054ed7 in QEventLoop::exec (this=0x7fffb74bd120, flags=...) at kernel/qeventloop.cpp:204
#39 0x00007f2236059f67 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#40 0x00007f22391bfa13 in kdemain (argc=1, argv=0x7fffb74bd508) at ../../../../plasma/desktop/shell/main.cpp:120
#41 0x00007f2238de276d in __libc_start_main (main=0x400640 <main(int, char**)>, argc=1, ubp_av=0x7fffb74bd508, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffb74bd4f8) at libc-start.c:226
#42 0x0000000000400671 in _start ()

Reported using DrKonqi