Application: kwin (4.8.90 (4.8.90))
KDE Platform Version: 4.8.90 (4.8.90)
Qt Version: 4.8.1
Operating System: Linux 3.2.0-26-generic-pae i686
Distribution: Ubuntu 12.04 LTS

-- Information about the crash:
- What I was doing when the application crashed:

I had been running a Konqueror Java applet which seemed to have left some hidden windows.  They showed up in alt-tab task list but not in the task bar.  When I alt-tabbed to them, no window appeared on the screen so I couldn't close them.

Howeverthere was also a Konqueror instance apaprently with no window title, just an icon.  I can't remember now if it showed up in the alt-tab list or only in the task bar, I hav a feeling it was the latter.  Eitehr way, when I selected that instance to close it, Kwin crashed immediately.

Not sure what the applet is, it's something supplied by my virtual hoster for VNC access to my virtual machine.  I will find out that and attempt to reproduce for other missing details, and append them later.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0xb1b2a740 (LWP 26717))]

Thread 3 (Thread 0xad56eb40 (LWP 26729)):
#0  0xb77be424 in __kernel_vsyscall ()
#1  0xb2acb96b in pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_wait.S:169
#2  0xb759b3dc in __pthread_cond_wait (cond=0xb67f1890, mutex=0xb67f1878) at forward.c:139
#3  0xb66ed029 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0xb67ec7a0) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#4  0xb66ed06f in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=0xb67ec7a0) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#5  0xb2ac7d4c in start_thread (arg=0xad56eb40) at pthread_create.c:308
#6  0xb758dace in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

Thread 2 (Thread 0xae1ffb40 (LWP 30190)):
#0  0xb2b0cdcd in __GI_clock_gettime (clock_id=1, tp=0xae1fefe8) at ../sysdeps/unix/clock_gettime.c:116
#1  0xb5f80315 in do_gettime (frac=0xae1fefe0, sec=0xae1fefd8) at tools/qelapsedtimer_unix.cpp:123
#2  qt_gettime () at tools/qelapsedtimer_unix.cpp:140
#3  0xb606a226 in QTimerInfoList::updateCurrentTime (this=0xad800b24) at kernel/qeventdispatcher_unix.cpp:343
#4  0xb606bc2b in QEventDispatcherUNIXPrivate::doSelect (this=0xad800488, flags=..., timeout=0x0) at kernel/qeventdispatcher_unix.cpp:186
#5  0xb606c1f4 in QEventDispatcherUNIX::processEvents (this=0xad80f540, flags=...) at kernel/qeventdispatcher_unix.cpp:926
#6  0xb603550d in QEventLoop::processEvents (this=0xae1ff240, flags=...) at kernel/qeventloop.cpp:149
#7  0xb60357a9 in QEventLoop::exec (this=0xae1ff240, flags=...) at kernel/qeventloop.cpp:204
#8  0xb5f1e94c in QThread::exec (this=0x996eb68) at thread/qthread.cpp:501
#9  0xb6012b5d in QInotifyFileSystemWatcherEngine::run (this=0x996eb68) at io/qfilesystemwatcher_inotify.cpp:248
#10 0xb5f21de0 in QThreadPrivate::start (arg=0x996eb68) at thread/qthread_unix.cpp:298
#11 0xb2ac7d4c in start_thread (arg=0xae1ffb40) at pthread_create.c:308
#12 0xb758dace in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

Thread 1 (Thread 0xb1b2a740 (LWP 26717)):
[KCrash Handler]
#7  KWin::TabBox::ClientModel::longestCaption (this=0x9654030) at ../../kwin/tabbox/clientmodel.cpp:96
#8  0xb776c7c0 in KWin::TabBox::DeclarativeView::showEvent (this=0x9946da8, event=0xbfacbc70) at ../../kwin/tabbox/declarative.cpp:169
#9  0xb557c659 in QWidget::event (this=0x9946da8, event=0xbfacbc70) at kernel/qwidget.cpp:8569
#10 0xb5999e45 in QFrame::event (this=0x9946da8, e=0xbfacbc70) at widgets/qframe.cpp:557
#11 0xb5a2e5d4 in QAbstractScrollArea::event (this=0x9946da8, e=0xbfacbc70) at widgets/qabstractscrollarea.cpp:996
#12 0xb5bf2cd8 in QGraphicsView::event (this=0x9946da8, event=0xbfacbc70) at graphicsview/qgraphicsview.cpp:2740
#13 0xb5521ed4 in notify_helper (e=0xbfacbc70, receiver=0x9946da8, this=0x95d9508) at kernel/qapplication.cpp:4559
#14 QApplicationPrivate::notify_helper (this=0x95d9508, receiver=0x9946da8, e=0xbfacbc70) at kernel/qapplication.cpp:4531
#15 0xb55273a2 in QApplication::notify (this=0x95d9508, receiver=0x9946da8, e=0xbfacbc70) at kernel/qapplication.cpp:4524
#16 0xb724b401 in KApplication::notify (this=0xbfacc634, receiver=0x9946da8, event=0xbfacbc70) at ../../kdeui/kernel/kapplication.cpp:311
#17 0xb76bca3f in notify (e=0xbfacbc70, o=0x9946da8, this=0xbfacc634) at ../../kwin/main.cpp:371
#18 KWin::Application::notify (this=0xbfacc634, o=0x9946da8, e=0xbfacbc70) at ../../kwin/main.cpp:367
#19 0xb603697e in QCoreApplication::notifyInternal (this=0xbfacc634, receiver=0x9946da8, event=0xbfacbc70) at kernel/qcoreapplication.cpp:876
#20 0xb557f28d in sendEvent (event=0xbfacbc70, receiver=0x9946da8) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#21 QWidgetPrivate::show_helper (this=0x9972bd0) at kernel/qwidget.cpp:7542
#22 0xb557f5c1 in QWidget::setVisible (this=0x9946da8, visible=true) at kernel/qwidget.cpp:7764
#23 0xb776e349 in show (this=0x9946da8) at /usr/include/qt4/QtGui/qwidget.h:494
#24 KWin::TabBox::TabBoxHandler::show (this=0x9641b80) at ../../kwin/tabbox/tabboxhandler.cpp:253
#25 0xb7763035 in show (this=0x965ccb8) at ../../kwin/tabbox/tabbox.cpp:660
#26 KWin::TabBox::TabBox::show (this=0x965ccb8) at ../../kwin/tabbox/tabbox.cpp:651
#27 0xb7766f97 in qt_static_metacall (_a=0xbfacbe20, _id=5, _o=0x965ccb8, _c=<optimized out>) at ./tabbox.moc:139
#28 KWin::TabBox::TabBox::qt_static_metacall (_o=0x965ccb8, _c=QMetaObject::InvokeMetaMethod, _id=5, _a=0xbfacbe20) at ./tabbox.moc:128
#29 0xb604d6b1 in QMetaObject::activate (sender=0x965ccd0, m=0xb61944d8, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3547
#30 0xb60a0625 in QTimer::timeout (this=0x965ccd0) at .moc/release-shared/moc_qtimer.cpp:148
#31 0xb6056566 in QTimer::timerEvent (this=0x965ccd0, e=0xbfacc34c) at kernel/qtimer.cpp:280
#32 0xb6051ac4 in QObject::event (this=0x965ccd0, e=0xbfacc34c) at kernel/qobject.cpp:1157
#33 0xb5521ed4 in notify_helper (e=0xbfacc34c, receiver=0x965ccd0, this=0x95d9508) at kernel/qapplication.cpp:4559
#34 QApplicationPrivate::notify_helper (this=0x95d9508, receiver=0x965ccd0, e=0xbfacc34c) at kernel/qapplication.cpp:4531
#35 0xb552730d in QApplication::notify (this=0xbfacc34c, receiver=0x965ccd0, e=0xbfacc34c) at kernel/qapplication.cpp:4288
#36 0xb724b401 in KApplication::notify (this=0xbfacc634, receiver=0x965ccd0, event=0xbfacc34c) at ../../kdeui/kernel/kapplication.cpp:311
#37 0xb76bca3f in notify (e=0xbfacc34c, o=0x965ccd0, this=0xbfacc634) at ../../kwin/main.cpp:371
#38 KWin::Application::notify (this=0xbfacc634, o=0x965ccd0, e=0xbfacc34c) at ../../kwin/main.cpp:367
#39 0xb603697e in QCoreApplication::notifyInternal (this=0xbfacc634, receiver=0x965ccd0, event=0xbfacc34c) at kernel/qcoreapplication.cpp:876
#40 0xb606b990 in sendEvent (event=0xbfacc34c, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#41 QTimerInfoList::activateTimers (this=0x95d9ec4) at kernel/qeventdispatcher_unix.cpp:611
#42 0xb606c207 in QEventDispatcherUNIX::processEvents (this=0x95d94e8, flags=...) at kernel/qeventdispatcher_unix.cpp:930
#43 0xb55dbb6e in QEventDispatcherX11::processEvents (this=0x95d94e8, flags=...) at kernel/qeventdispatcher_x11.cpp:152
#44 0xb603550d in QEventLoop::processEvents (this=0xbfacc594, flags=...) at kernel/qeventloop.cpp:149
#45 0xb60357a9 in QEventLoop::exec (this=0xbfacc594, flags=...) at kernel/qeventloop.cpp:204
#46 0xb603aeba in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#47 0xb551fa74 in QApplication::exec () at kernel/qapplication.cpp:3820
#48 0xb76bf8f6 in kdemain (argc=3, argv=0xbfacc8d4) at ../../kwin/main.cpp:545
#49 0x0804850b in main (argc=3, argv=0xbfacc8d4) at kwin_dummy.cpp:3

Reported using DrKonqi