Application: plasma-desktop (0.4)
KDE Platform Version: 4.5.85 (4.6 Beta2)
Qt Version: 4.7.0
Operating System: Linux 2.6.35-23-generic x86_64
Distribution: Ubuntu 10.10

-- Information about the crash:
Sometimes when I start up the KDE desktop, plasma-desktop will crash and leave me with a black screen.  I've found that if I delete the plasma config file plasma-desktop-appletsrc and restart plasma-desktop the desktop returns.  However if I do not, plasma-desktop will not start.  I will attach the config file that I had when it crashed to the bug report.

The crash can be reproduced some of the time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f6dcdd45780 (LWP 1666))]

Thread 4 (Thread 0x7f6da6ed5710 (LWP 1686)):
#0  0x00007f6dc2b50665 in __pthread_mutex_lock (mutex=0x3388448) at pthread_mutex_lock.c:61
#1  0x00007f6dc2496a61 in g_main_context_query () from /lib/libglib-2.0.so.0
#2  0x00007f6dc249befc in ?? () from /lib/libglib-2.0.so.0
#3  0x00007f6dc249c45c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#4  0x00007f6dca9ce1e6 in QEventDispatcherGlib::processEvents (this=0x32d84b0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:417
#5  0x00007f6dca9a0a02 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#6  0x00007f6dca9a0dec in QEventLoop::exec (this=0x7f6da6ed4d90, flags=) at kernel/qeventloop.cpp:201
#7  0x00007f6dca8ab2fd in QThread::exec (this=<value optimized out>) at thread/qthread.cpp:490
#8  0x00007f6dca9805f8 in QInotifyFileSystemWatcherEngine::run (this=0x3383770) at io/qfilesystemwatcher_inotify.cpp:248
#9  0x00007f6dca8ae27e in QThreadPrivate::start (arg=0x3383770) at thread/qthread_unix.cpp:266
#10 0x00007f6dc2b4e971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#11 0x00007f6dcd65394d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7f6da66d4710 (LWP 1687)):
#0  0xffffffffff60017b in ?? ()
#1  0x00007f6da66d3a90 in ?? ()
#2  0x00007fff4475b852 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Thread 2 (Thread 0x7f6da4001710 (LWP 1688)):
#0  0x00007f6dc2b51c9d in __pthread_mutex_unlock_usercnt (mutex=0x34cea28) at pthread_mutex_unlock.c:52
#1  __pthread_mutex_unlock (mutex=0x34cea28) at pthread_mutex_unlock.c:290
#2  0x00007f6dc249ba05 in g_main_context_prepare () from /lib/libglib-2.0.so.0
#3  0x00007f6dc249be78 in ?? () from /lib/libglib-2.0.so.0
#4  0x00007f6dc249c45c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#5  0x00007f6dca9ce1e6 in QEventDispatcherGlib::processEvents (this=0x3283c50, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:417
#6  0x00007f6dca9a0a02 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#7  0x00007f6dca9a0dec in QEventLoop::exec (this=0x7f6da4000d90, flags=) at kernel/qeventloop.cpp:201
#8  0x00007f6dca8ab2fd in QThread::exec (this=<value optimized out>) at thread/qthread.cpp:490
#9  0x00007f6dca9805f8 in QInotifyFileSystemWatcherEngine::run (this=0x343fbc0) at io/qfilesystemwatcher_inotify.cpp:248
#10 0x00007f6dca8ae27e in QThreadPrivate::start (arg=0x343fbc0) at thread/qthread_unix.cpp:266
#11 0x00007f6dc2b4e971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#12 0x00007f6dcd65394d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#13 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f6dcdd45780 (LWP 1666)):
[KCrash Handler]
#6  QGraphicsLayoutItem::isLayout (this=0x34) at graphicsview/qgraphicslayoutitem.cpp:804
#7  0x00007f6dca33f92a in QGraphicsLayoutPrivate::addChildLayoutItem (this=0x35c9f40, layoutItem=0x35c9cf0) at graphicsview/qgraphicslayout_p.cpp:151
#8  0x00007f6dca341aa4 in QGraphicsLinearLayout::insertItem (this=0x33e7120, index=0, item=0x35c9cf0) at graphicsview/qgraphicslinearlayout.cpp:278
#9  0x00007f6dcd18c489 in Plasma::Extender::itemAddedEvent (this=0x35b4c10, item=0x35c9cd0, pos=<value optimized out>) at ../../plasma/extenders/extender.cpp:497
#10 0x00007f6dcd18921c in Plasma::ExtenderPrivate::delayItemAddedEvent (this=0x35b4300) at ../../plasma/extenders/extender.cpp:805
#11 0x00007f6dcd18d722 in Plasma::Extender::qt_metacall (this=0x35b4c10, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x3363b10) at ./extender.moc:105
#12 0x00007f6dca9b3bde in QObject::event (this=0x35b4c10, e=0x34) at kernel/qobject.cpp:1219
#13 0x00007f6dca38414b in QGraphicsWidget::event (this=0x35b4c10, event=0x3528680) at graphicsview/qgraphicswidget.cpp:1405
#14 0x00007f6dc9d08fdc in QApplicationPrivate::notify_helper (this=0x25b8260, receiver=0x35b4c10, e=0x3528680) at kernel/qapplication.cpp:4396
#15 0x00007f6dc9d0eaed in QApplication::notify (this=0x258a3e0, receiver=0x35b4c10, e=0x3528680) at kernel/qapplication.cpp:4277
#16 0x00007f6dcb6a1f36 in KApplication::notify (this=0x258a3e0, receiver=0x35b4c10, event=0x3528680) at ../../kdeui/kernel/kapplication.cpp:311
#17 0x00007f6dca9a1cdc in QCoreApplication::notifyInternal (this=0x258a3e0, receiver=0x35b4c10, event=0x3528680) at kernel/qcoreapplication.cpp:732
#18 0x00007f6dca9a4c22 in sendEvent (receiver=0x0, event_type=<value optimized out>, data=0x255bba0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#19 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=<value optimized out>, data=0x255bba0) at kernel/qcoreapplication.cpp:1373
#20 0x00007f6dca9ce653 in sendPostedEvents (s=0x25bb810) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#21 postEventSourceDispatch (s=0x25bb810) at kernel/qeventdispatcher_glib.cpp:277
#22 0x00007f6dc2498342 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#23 0x00007f6dc249c2a8 in ?? () from /lib/libglib-2.0.so.0
#24 0x00007f6dc249c45c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#25 0x00007f6dca9ce193 in QEventDispatcherGlib::processEvents (this=0x255b250, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:415
#26 0x00007f6dc9dbba4e in QGuiEventDispatcherGlib::processEvents (this=0x34, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#27 0x00007f6dca9a0a02 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#28 0x00007f6dca9a0dec in QEventLoop::exec (this=0x7fff44715650, flags=) at kernel/qeventloop.cpp:201
#29 0x00007f6dca9a4ebb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1009
#30 0x00007f6dcd931743 in kdemain () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#31 0x00007f6dcd58bd8e in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fff44715a28) at libc-start.c:226
#32 0x0000000000400669 in _start ()

Possible duplicates by query: bug 257188, bug 256245.

Reported using DrKonqi