Application: konqueror (4.3.74 (KDE 4.3.74 (KDE 4.4 >= 20091102)))
KDE Version: 4.3.74 (KDE 4.3.74 (KDE 4.4 >= 20091102)) (Compiled from sources)
Qt Version: 4.7.0
Operating System: Linux 2.6.30.5-43.fc11.x86_64 x86_64

What I was doing when the application crashed:
Konqueror DOM viewer crashes with Qt 4.6 trunk and KDE 4.4 trunk. Sometimes instantly, sometimes not.

 -- Backtrace:
Application: Konqueror (konqueror), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f4be8df9800 (LWP 24320))]

Thread 3 (Thread 0x7f4be14e9910 (LWP 24666)):
#0  0x0000003656a0b57d in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f4bea45b492 in QWaitConditionPrivate::wait (time=<value optimized out>, this=<value optimized out>) at thread/qwaitcondition_unix.cpp:85
#2  QWaitCondition::wait (time=<value optimized out>, this=<value optimized out>) at thread/qwaitcondition_unix.cpp:159
#3  0x00007f4bea450ba1 in QThreadPoolThread::run (this=0x2638d50) at concurrent/qthreadpool.cpp:140
#4  0x00007f4bea45a565 in QThreadPrivate::start (arg=0x2638d50) at thread/qthread_unix.cpp:244
#5  0x0000003656a0686a in start_thread () from /lib64/libpthread.so.0
#6  0x0000003655ede3bd in clone () from /lib64/libc.so.6
#7  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f4be0ae8910 (LWP 24671)):
#0  0x0000003656a0b57d in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f4bea45b492 in QWaitConditionPrivate::wait (time=<value optimized out>, this=<value optimized out>) at thread/qwaitcondition_unix.cpp:85
#2  QWaitCondition::wait (time=<value optimized out>, this=<value optimized out>) at thread/qwaitcondition_unix.cpp:159
#3  0x00007f4bea450ba1 in QThreadPoolThread::run (this=0x26e9590) at concurrent/qthreadpool.cpp:140
#4  0x00007f4bea45a565 in QThreadPrivate::start (arg=0x26e9590) at thread/qthread_unix.cpp:244
#5  0x0000003656a0686a in start_thread () from /lib64/libpthread.so.0
#6  0x0000003655ede3bd in clone () from /lib64/libc.so.6
#7  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f4be8df9800 (LWP 24320)):
[KCrash Handler]
#5  0x00007f4be9e9299d in QListData::size (this=<value optimized out>) at ../../include/QtCore/../../src/corelib/tools/qlist.h:90
#6  QList<QTreeWidgetItem*>::count (this=<value optimized out>) at ../../include/QtCore/../../src/corelib/tools/qlist.h:261
#7  QTreeModel::index (this=<value optimized out>) at itemviews/qtreewidget.cpp:241
#8  0x00007f4be9e95b03 in QTreeWidgetPrivate::index (column=<value optimized out>, item=<value optimized out>, this=<value optimized out>)
    at ../../include/QtGui/private/../../../src/gui/itemviews/qtreewidget_p.h:224
#9  QTreeWidget::setItemExpanded (column=<value optimized out>, item=<value optimized out>, this=<value optimized out>) at itemviews/qtreewidget.cpp:3126
#10 0x00007f4bd16bf63b in DOMTreeView::showRecursive (this=0x42e63d0, pNode=@0x7fff9c314190, node=@0x7fff9c3141b0, depth=0)
    at /home/thorgt/kde/src/extragear/base/konq-plugins/domtreeviewer/domtreeview.cpp:261
#11 0x00007f4bd16bfc52 in DOMTreeView::slotShowTree (this=0x42e63d0, pNode=<value optimized out>) at /home/thorgt/kde/src/extragear/base/konq-plugins/domtreeviewer/domtreeview.cpp:235
#12 0x00007f4bd16bff70 in DOMTreeView::connectToDocument (this=0x42e63d0) at /home/thorgt/kde/src/extragear/base/konq-plugins/domtreeviewer/domtreeview.cpp:906
#13 0x00007f4bd16c0559 in DOMTreeView::connectToPart (this=0x42e63d0) at /home/thorgt/kde/src/extragear/base/konq-plugins/domtreeviewer/domtreeview.cpp:869
#14 0x00007f4bd16c05b9 in DOMTreeView::slotSetHtmlPartDelayed (this=0x7fff9c313fd0) at /home/thorgt/kde/src/extragear/base/konq-plugins/domtreeviewer/domtreeview.cpp:927
#15 0x00007f4bd16c094e in DOMTreeView::qt_metacall (this=0x42e63d0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff9c314560)
    at /home/thorgt/kde/build/extragear/base/konq-plugins/domtreeviewer/domtreeview.moc:162
#16 0x00007f4bea55f2b3 in QMetaObject::activate (sender=0x40bdf10, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3391
#17 0x00007f4bea56670f in QSingleShotTimer::timerEvent (this=0x40bdf10) at kernel/qtimer.cpp:308
#18 0x00007f4bea55bb9e in QObject::event (this=0x40bdf10, e=0x7fff9c314c20) at kernel/qobject.cpp:1202
#19 0x00007f4be992f11c in QApplicationPrivate::notify_helper (this=0x1c4bdd0, receiver=0x40bdf10, e=0x7fff9c314c20) at kernel/qapplication.cpp:4250
#20 0x00007f4be993571d in QApplication::notify (this=0x7fff9c315170, receiver=0x40bdf10, e=0x7fff9c314c20) at kernel/qapplication.cpp:4139
#21 0x00007f4beb3b38ee in KApplication::notify (this=0x7fff9c315170, receiver=0x40bdf10, event=0x7fff9c314c20) at /home/thorgt/kde/src/KDE/kdelibs/kdeui/kernel/kapplication.cpp:302
#22 0x00007f4bea54c3cc in QCoreApplication::notifyInternal (this=0x7fff9c315170, receiver=0x40bdf10, event=0x7fff9c314c20) at kernel/qcoreapplication.cpp:704
#23 0x00007f4bea578b92 in QCoreApplication::sendEvent (event=<value optimized out>, receiver=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#24 QTimerInfoList::activateTimers (event=<value optimized out>, receiver=<value optimized out>) at kernel/qeventdispatcher_unix.cpp:603
#25 0x00007f4bea5757f8 in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:184
#26 idleTimerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:231
#27 0x0000003657a3790e in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#28 0x0000003657a3b0e8 in ?? () from /lib64/libglib-2.0.so.0
#29 0x0000003657a3b20a in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#30 0x00007f4bea5754c3 in QEventDispatcherGlib::processEvents (this=0x1c2ff60, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:407
#31 0x00007f4be99d3f7e in QGuiEventDispatcherGlib::processEvents (this=0x7fff9c313fd0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#32 0x00007f4bea54ad12 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 36}) at kernel/qeventloop.cpp:149
#33 0x00007f4bea54b0ec in QEventLoop::exec (this=0x7fff9c314ec0, flags={i = 0}) at kernel/qeventloop.cpp:201
#34 0x00007f4bea54eddb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#35 0x00007f4becbba867 in kdemain (argc=<value optimized out>, argv=<value optimized out>) at /home/thorgt/kde/src/KDE/kdebase/apps/konqueror/src/konqmain.cpp:257
#36 0x0000003655e1ea2d in __libc_start_main () from /lib64/libc.so.6
#37 0x0000000000400789 in _start ()

Reported using DrKonqi