Application: kwin (4.4.4 (KDE 4.4.4))
KDE Platform Version: 4.4.4 (KDE 4.4.4)
Qt Version: 4.6.3
Operating System: Linux 2.6.34-ARCH i686
Distribution (Platform): Archlinux Packages

-- Information about the crash:
How to Reproduce:
1. Enable compositing and enable "Cover switch" and "Slow(er)" animation effects
2. Press Alt+F1 (we can see kickoff menu)
3. Now press Alt+Tab (and switch and *hold* to kickoff-menu which is labelled "plasma-desktop")
4. "As soon as we release the mouse button" continuously (two or three times) click on the the "Cover Switched Kick-off menu" (click on the zoomed-down kickoff menu, the next moment before it recovers/exits the cover switch)
5. plasma desktop crashes.

Unexpected Behavior:
The kickoff menu is shown in 'alt+tab cover switch menu' as "plasma-desktop", and clicking the menu before 'exiting cover switch mode' crashes plasma-desktop


Expected Behavior:

1. Other applications/windows do not crash when clicked while the cover effects is still running on, as soon as the alt+tab cover switch is done.

thanks.

The crash can be reproduced every time.

 -- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
[KCrash Handler]
#6  0xb6e2fda3 in QList<KWin::WindowQuad>::free(QListData::Data*) () from /usr/lib/libkwineffects.so.1
#7  0xb6e33f70 in KWin::WindowPaintData::WindowPaintData(KWin::EffectWindow*) () from /usr/lib/libkwineffects.so.1
#8  0xb042e930 in KWin::CoverSwitchEffect::paintFrontWindow(KWin::EffectWindow*, int, int, int, bool) () from /usr/lib/kde4/kwin4_effect_builtins.so
#9  0xb042ef43 in KWin::CoverSwitchEffect::paintScene(KWin::EffectWindow*, QList<KWin::EffectWindow*> const&, QList<KWin::EffectWindow*> const&, bool) () from /usr/lib/kde4/kwin4_effect_builtins.so
#10 0xb0430112 in KWin::CoverSwitchEffect::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/kde4/kwin4_effect_builtins.so
#11 0xb76b1b52 in KWin::EffectsHandlerImpl::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkdeinit4_kwin.so
#12 0xb6e2fc96 in KWin::Effect::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkwineffects.so.1
#13 0xb76b1b52 in KWin::EffectsHandlerImpl::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkdeinit4_kwin.so
#14 0xb6e2fc96 in KWin::Effect::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkwineffects.so.1
#15 0xb76b1b52 in KWin::EffectsHandlerImpl::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkdeinit4_kwin.so
#16 0xb6e2fc96 in KWin::Effect::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkwineffects.so.1
#17 0xb76b1b52 in KWin::EffectsHandlerImpl::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkdeinit4_kwin.so
#18 0xb6e2fc96 in KWin::Effect::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkwineffects.so.1
#19 0xb76b1b52 in KWin::EffectsHandlerImpl::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkdeinit4_kwin.so
#20 0xb6e2fc96 in KWin::Effect::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkwineffects.so.1
#21 0xb76b1b52 in KWin::EffectsHandlerImpl::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkdeinit4_kwin.so
#22 0xb042b820 in KWin::ZoomEffect::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/kde4/kwin4_effect_builtins.so
#23 0xb76b1b52 in KWin::EffectsHandlerImpl::paintScreen(int, QRegion, KWin::ScreenPaintData&) () from /usr/lib/libkdeinit4_kwin.so
#24 0xb769d174 in KWin::Scene::paintScreen(int*, QRegion*) () from /usr/lib/libkdeinit4_kwin.so
#25 0xb76ac4c2 in KWin::SceneOpenGL::paint(QRegion, QList<KWin::Toplevel*>) () from /usr/lib/libkdeinit4_kwin.so
#26 0xb7696a51 in KWin::Workspace::performCompositing() () from /usr/lib/libkdeinit4_kwin.so
#27 0xb7614f96 in KWin::Workspace::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdeinit4_kwin.so
#28 0xb5df2eba in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#29 0xb5e01f9b in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#30 0xb5e4c567 in QTimer::timeout() () from /usr/lib/libQtCore.so.4
#31 0xb5e0709e in QTimer::timerEvent(QTimerEvent*) () from /usr/lib/libQtCore.so.4
#32 0xb5dff644 in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#33 0xb60a7f14 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#34 0xb60ac0fe in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#35 0xb72ef24a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#36 0xb762f60f in KWin::Application::notify(QObject*, QEvent*) () from /usr/lib/libkdeinit4_kwin.so
#37 0xb5dececb in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#38 0xb5e1a80e in ?? () from /usr/lib/libQtCore.so.4
#39 0xb5e177b7 in ?? () from /usr/lib/libQtCore.so.4
#40 0xb2cfef72 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#41 0xb2cff750 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#42 0xb2cffa04 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#43 0xb5e17e7c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#44 0xb61541b5 in ?? () from /usr/lib/libQtGui.so.4
#45 0xb5dec119 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#46 0xb5dec38a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#47 0xb5df0c6f in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#48 0xb60a5637 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#49 0xb7631a37 in kdemain () from /usr/lib/libkdeinit4_kwin.so
#50 0x0804853b in _start ()

Reported using DrKonqi