Version:            (using KDE 4.2.0)
OS:                Linux
Installed from:    Mandriva RPMs

The following may not be accurate, but at least I have a backtrace.

I was debugging a program that crashed. Apparently, a button remained in the taskbar, with no window associated with. I clicked on it thinking it was another window, and after a few clicks, plasma crashed.

Here is the backtrace:

Application : Espace de travail Plasma (plasma), signal SIGSEGV
[Current thread is 1 (Thread 0xb44456f0 (LWP 2934))]

Thread 3 (Thread 0xa891db90 (LWP 2935)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb581fb95 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i686/libpthread.so.0
#2  0xb7f1f18d in pthread_cond_wait () from /lib/i686/libc.so.6
#3  0xb689d9ab in QWaitCondition::wait (this=0x9c78a40, mutex=0x9c78a3c, time=4294967295) at thread/qwaitcondition_unix.cpp:82
#4  0xb58c054c in QHostInfoAgent::run (this=0x9c78a30) at kernel/qhostinfo.cpp:241
#5  0xb689c89f in QThreadPrivate::start (arg=0x9c78a30) at thread/qthread_unix.cpp:185
#6  0xb581c315 in start_thread () from /lib/i686/libpthread.so.0
#7  0xb7f11d4e in clone () from /lib/i686/libc.so.6

Thread 2 (Thread 0xa80d6b90 (LWP 2940)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb581fb95 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i686/libpthread.so.0
#2  0xb7f1f18d in pthread_cond_wait () from /lib/i686/libc.so.6
#3  0xb689d9ab in QWaitCondition::wait (this=0x98c29e0, mutex=0x98c29dc, time=4294967295) at thread/qwaitcondition_unix.cpp:82
#4  0xa8fa6e2e in RenderThread::run (this=0x98c29d4) at /usr/src/debug/kdebase-workspace-4.2.0/plasma/wallpapers/image/renderthread.cpp:91
#5  0xb689c89f in QThreadPrivate::start (arg=0x98c29d4) at thread/qthread_unix.cpp:185
#6  0xb581c315 in start_thread () from /lib/i686/libpthread.so.0
#7  0xb7f11d4e in clone () from /lib/i686/libc.so.6

Thread 1 (Thread 0xb44456f0 (LWP 2934)):
[KCrash Handler]
#6  QImage::scanLine (this=0xbff36738, i=0) at image/qimage.cpp:1751
#7  0xb6ca521b in QWidgetPrivate::setWindowIcon_sys (this=0xec535e8, forceReset=false) at kernel/qwidget_x11.cpp:1226
#8  0xb6c6e478 in QWidget::create (this=0xbff36864, window=0, initializeWindow=<value optimized out>, destroyOldWindow=<value optimized out>) at kernel/qwidget.cpp:1267
#9  0xb6c6a048 in QWidgetPrivate::createWinId (this=0xec535e8, winid=0) at kernel/qwidget.cpp:2014
#10 0xb6c6df36 in QWidget::createWinId (this=0xbff36864) at kernel/qwidget.cpp:2030
#11 0xb70127ed in QMenu::exec (this=0xbff36864, p=@0xbff36878, action=0x0) at widgets/qmenu.cpp:1932
#12 0xa8a718c8 in WindowTaskItem::contextMenuEvent (this=0xed84180, e=0xbff36dac) at /usr/src/debug/kdebase-workspace-4.2.0/plasma/applets/tasks/windowtaskitem.cpp:276
#13 0xb71c2f1b in QGraphicsItem::sceneEvent (this=0xed84188, event=0xbff36dac) at graphicsview/qgraphicsitem.cpp:3971
#14 0xb7208787 in QGraphicsWidget::sceneEvent (this=0xed84180, event=0xbff36dac) at graphicsview/qgraphicswidget.cpp:1016
#15 0xb71e1ee4 in QGraphicsScenePrivate::sendEvent (this=0x9709720, item=0xed84188, event=0xbff36dac) at graphicsview/qgraphicsscene.cpp:1024
#16 0xb71e8617 in QGraphicsScene::contextMenuEvent (this=0x979f8c8, contextMenuEvent=0xbff36dac) at graphicsview/qgraphicsscene.cpp:3101
#17 0xb71eb723 in QGraphicsScene::event (this=0x979f8c8, event=0xbff36dac) at graphicsview/qgraphicsscene.cpp:2943
#18 0xb6c15ffc in QApplicationPrivate::notify_helper (this=0x96f98e8, receiver=0x979f8c8, e=0xbff36dac) at kernel/qapplication.cpp:3803
#19 0xb6c1e255 in QApplication::notify (this=0x96dfaf0, receiver=0x979f8c8, e=0xbff36dac) at kernel/qapplication.cpp:3393
#20 0xb780be20 in KApplication::notify (this=0x96dfaf0, receiver=0x979f8c8, event=0xbff36dac) at /usr/src/debug/kdelibs-4.2.0/kdeui/kernel/kapplication.cpp:307
#21 0xb6995853 in QCoreApplication::notifyInternal (this=0x96dfaf0, receiver=0x979f8c8, event=0xbff36dac) at kernel/qcoreapplication.cpp:587
#22 0xb71f8678 in QGraphicsView::contextMenuEvent (this=0x9c95de8, event=0xbff37360) at ../../src/corelib/kernel/qcoreapplication.h:209
#23 0xb6c70d44 in QWidget::event (this=0x9c95de8, event=0xbff37360) at kernel/qwidget.cpp:7320
#24 0xb6fc5e85 in QFrame::event (this=0x9c95de8, e=0xbff37360) at widgets/qframe.cpp:651
#25 0xb70604c0 in QAbstractScrollArea::viewportEvent (this=0x9c95de8, e=0x0) at widgets/qabstractscrollarea.cpp:943
#26 0xb71fb588 in QGraphicsView::viewportEvent (this=0x9c95de8, event=0xbff37360) at graphicsview/qgraphicsview.cpp:2337
#27 0xb7062aa6 in QAbstractScrollAreaFilter::eventFilter (this=0x9c9f688, o=0x9c96818, e=0xbff37360) at widgets/qabstractscrollarea_p.h:96
#28 0xb69949ce in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x96f98e8, receiver=0x9c96818, event=0xbff37360) at kernel/qcoreapplication.cpp:694
#29 0xb6c15fcf in QApplicationPrivate::notify_helper (this=0x96f98e8, receiver=0x9c96818, e=0xbff37360) at kernel/qapplication.cpp:3799
#30 0xb6c1e797 in QApplication::notify (this=0x96dfaf0, receiver=0x9c96818, e=0xbff37360) at kernel/qapplication.cpp:3614
#31 0xb780be20 in KApplication::notify (this=0x96dfaf0, receiver=0x9c96818, event=0xbff37360) at /usr/src/debug/kdelibs-4.2.0/kdeui/kernel/kapplication.cpp:307
#32 0xb6995853 in QCoreApplication::notifyInternal (this=0x96dfaf0, receiver=0x9c96818, event=0xbff37360) at kernel/qcoreapplication.cpp:587
#33 0xb6c2140d in QCoreApplication::sendSpontaneousEvent (receiver=0x9c96818, event=0x0) at ../../src/corelib/kernel/qcoreapplication.h:212
#34 0xb6c8d852 in QETWidget::translateMouseEvent (this=0x9c95de8, event=0xbff378ec) at kernel/qapplication_x11.cpp:4118
#35 0xb6c8c580 in QApplication::x11ProcessEvent (this=0x96dfaf0, event=0xbff378ec) at kernel/qapplication_x11.cpp:3108
#36 0xb6cb5674 in x11EventSourceDispatch (s=0x970a4e8, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:142
#37 0xb56f47ca in IA__g_main_context_dispatch (context=0x96ffaa0) at gmain.c:2142
#38 0xb56f7ee8 in g_main_context_iterate (context=0x96ffaa0, block=1, dispatch=1, self=0x96fab40) at gmain.c:2776
#39 0xb56f80a8 in IA__g_main_context_iteration (context=0x96ffaa0, may_block=1) at gmain.c:2839
#40 0xb69c134a in QEventDispatcherGlib::processEvents (this=0x96f9a88, flags={i = -1074562408}) at kernel/qeventdispatcher_glib.cpp:319
#41 0xb6cb4dca in QGuiEventDispatcherGlib::processEvents (this=0x96f9a88, flags={i = -1074562360}) at kernel/qguieventdispatcher_glib.cpp:198
#42 0xb6993ec3 in QEventLoop::processEvents (this=0xbff37b40, flags={i = -1074562296}) at kernel/qeventloop.cpp:143
#43 0xb6994081 in QEventLoop::exec (this=0xbff37b40, flags={i = -1074562232}) at kernel/qeventloop.cpp:194
#44 0xb69967f2 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#45 0xb6c15e64 in QApplication::exec () at kernel/qapplication.cpp:3331
#46 0xb7fb36b1 in kdemain (argc=1, argv=0xbff37ce4) at /usr/src/debug/kdebase-workspace-4.2.0/plasma/shells/desktop/main.cpp:54
#47 0x0804854f in main (argc=) at /usr/src/debug/kdebase-workspace-4.2.0/build/plasma/shells/desktop/plasma_qgv_dummy.cpp:3