Application: plasma-desktop (4.11.1)
KDE Platform Version: 4.11.1
Qt Version: 4.8.5
Operating System: Linux 3.10.10-1-ARCH x86_64
Distribution (Platform): Archlinux Packages

-- Information about the crash:
- What I was doing when the application crashed:
Trying to switch over to non-grouped windows. I had tried to ungroup through settings before: http://forum.kde.org/viewtopic.php?f=83&t=98489 albeit KDE4 still groups similar tasks. So I decided to right click on leafpad > More Action > Do not allow this program to be grouped.

- Unusual behavior I noticed:
plasma-desktop crashed, kicker panel (I think that's what it was called) disappeared and I immediately lost my personalised background (background went to solid black). My other programs such as Dolphin and Gkrellm were still running (visible) but I cannot see other programs that was on the kicker panel.

Although after Crash Reporting Assistant loaded up I got plasma-desktop reloaded. I have tried grouping leafpad programs together but plasma-desktop crashed (again). After plasma-desktop came back, I tried ungrouping leafpad programs and same thing (plasma-desktop crashed). I'd say the occurance of this bug to appear would be always.

- Custom settings of the application:
None that I am aware of. leafpad is not part of KDE suite but it has become my GUI text editor of choice. I only had two instances which made KDE group them (along with other tasks that I did not want grouping to occur in any of them).

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fe928508780 (LWP 4035))]

Thread 4 (Thread 0x7fe903330700 (LWP 4036)):
#0  0x00007fe926dd603f in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0
#1  0x00007fe9132c7fcb in ?? () from /usr/lib/libQtScript.so.4
#2  0x00007fe9132c8009 in ?? () from /usr/lib/libQtScript.so.4
#3  0x00007fe926dd20a2 in start_thread () from /usr/lib/libpthread.so.0
#4  0x00007fe925b56a2d in clone () from /usr/lib/libc.so.6

Thread 3 (Thread 0x7fe877db5700 (LWP 4038)):
#0  0x00007fe922cabe6a in ?? () from /usr/lib/libglib-2.0.so.0
#1  0x00007fe922cac119 in g_mutex_lock () from /usr/lib/libglib-2.0.so.0
#2  0x00007fe922c6c5f7 in g_main_context_prepare () from /usr/lib/libglib-2.0.so.0
#3  0x00007fe922c6cfa3 in ?? () from /usr/lib/libglib-2.0.so.0
#4  0x00007fe922c6d18c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#5  0x00007fe92718fb46 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#6  0x00007fe927161b1f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#7  0x00007fe927161e15 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#8  0x00007fe9270606ef in QThread::exec() () from /usr/lib/libQtCore.so.4
#9  0x00007fe9271432c3 in ?? () from /usr/lib/libQtCore.so.4
#10 0x00007fe927062d8f in ?? () from /usr/lib/libQtCore.so.4
#11 0x00007fe926dd20a2 in start_thread () from /usr/lib/libpthread.so.0
#12 0x00007fe925b56a2d in clone () from /usr/lib/libc.so.6

Thread 2 (Thread 0x7fe876d2a700 (LWP 4039)):
#0  0x00007fe926dd4379 in pthread_mutex_lock () from /usr/lib/libpthread.so.0
#1  0x00007fe922cac121 in g_mutex_lock () from /usr/lib/libglib-2.0.so.0
#2  0x00007fe922c6c318 in g_main_context_release () from /usr/lib/libglib-2.0.so.0
#3  0x00007fe922c6d031 in ?? () from /usr/lib/libglib-2.0.so.0
#4  0x00007fe922c6d18c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#5  0x00007fe92718fb46 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#6  0x00007fe927161b1f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#7  0x00007fe927161e15 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#8  0x00007fe9270606ef in QThread::exec() () from /usr/lib/libQtCore.so.4
#9  0x00007fe9271432c3 in ?? () from /usr/lib/libQtCore.so.4
#10 0x00007fe927062d8f in ?? () from /usr/lib/libQtCore.so.4
#11 0x00007fe926dd20a2 in start_thread () from /usr/lib/libpthread.so.0
#12 0x00007fe925b56a2d in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7fe928508780 (LWP 4035)):
[KCrash Handler]
#5  0x00007fe926884b67 in QGraphicsItem::ungrabMouse() () from /usr/lib/libQtGui.so.4
#6  0x00007fe9268b1bdf in ?? () from /usr/lib/libQtGui.so.4
#7  0x00007fe9268b4cfd in ?? () from /usr/lib/libQtGui.so.4
#8  0x00007fe9268bda26 in QGraphicsScene::mouseMoveEvent(QGraphicsSceneMouseEvent*) () from /usr/lib/libQtGui.so.4
#9  0x00007fe9268c995c in QGraphicsScene::event(QEvent*) () from /usr/lib/libQtGui.so.4
#10 0x00007fe9262e912c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#11 0x00007fe9262ef6f0 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#12 0x00007fe927f1372a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#13 0x00007fe927162ebd in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#14 0x00007fe9268debdc in QGraphicsViewPrivate::mouseMoveEventHandler(QMouseEvent*) () from /usr/lib/libQtGui.so.4
#15 0x00007fe9268dfaea in QGraphicsView::mouseMoveEvent(QMouseEvent*) () from /usr/lib/libQtGui.so.4
#16 0x00007fe9263387a5 in QWidget::event(QEvent*) () from /usr/lib/libQtGui.so.4
#17 0x00007fe9266d58ee in QFrame::event(QEvent*) () from /usr/lib/libQtGui.so.4
#18 0x00007fe9268e1139 in QGraphicsView::viewportEvent(QEvent*) () from /usr/lib/libQtGui.so.4
#19 0x00007fe927163026 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#20 0x00007fe9262e910c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#21 0x00007fe9262ef82d in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#22 0x00007fe927f1372a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#23 0x00007fe927162ebd in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#24 0x00007fe9262eefe3 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib/libQtGui.so.4
#25 0x00007fe926360bfb in ?? () from /usr/lib/libQtGui.so.4
#26 0x00007fe92635f66c in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/libQtGui.so.4
#27 0x00007fe9263861b2 in ?? () from /usr/lib/libQtGui.so.4
#28 0x00007fe922c6cd96 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#29 0x00007fe922c6d0e8 in ?? () from /usr/lib/libglib-2.0.so.0
#30 0x00007fe922c6d18c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#31 0x00007fe92718fb25 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#32 0x00007fe926386266 in ?? () from /usr/lib/libQtGui.so.4
#33 0x00007fe927161b1f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#34 0x00007fe927161e15 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#35 0x00007fe927166f4b in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#36 0x00007fe90c6b62cc in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#37 0x0000000000408069 in _start ()

Possible duplicates by query: bug 324844.

Reported using DrKonqi