Application: kwin_x11 (5.0.0)
 (Compiled from sources)
Qt Version: 5.3.1
Operating System: Linux 3.14-2-amd64 x86_64
Distribution: Debian GNU/Linux testing (jessie)

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

Starting Plasma 5 (every session start in the last few days, crashes a few times in a row - usually two)
Sometimes when opening yakuake, mplayer, etc.

- Custom settings of the application:

Happened both with opengl 3.1 and 3.0
Decorations: Oxygen
Sources updated yesterday (the issue was here even before that)
Decoration border set to: No Border


The crash can be reproduced often

.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f81397fd7c0 (LWP 1242))]

Thread 1 (Thread 0x7f81397fd7c0 (LWP 1242)):
[KCrash Handler]
#6  0x00007f8138f683c6 in KCommonDecoration::isActive (this=0x12f52d0) at /opt/kf5/src/kde/workspace/kwin/libkdecorations/kcommondecoration.cpp:1201
#7  0x00007f811a1d2049 in Oxygen::SizeGrip::paintEvent (this=0x12f8740) at /opt/kf5/src/kde/workspace/oxygen/kwin-decoration/oxygensizegrip.cpp:131
#8  0x00007f8131390978 in QWidget::event(QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#9  0x00007f8131354edc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#10 0x00007f813135a13e in QApplication::notify(QObject*, QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#11 0x00007f813921dc09 in KWin::Application::notify (this=0x7fff5f161f40, o=0x12f8740, e=0x7fff5f1617c0) at /opt/kf5/src/kde/workspace/kwin/main.cpp:344
#12 0x00007f813069dcd3 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Core.so.5
#13 0x00007f813138b4cd in QWidgetPrivate::drawWidget(QPaintDevice*, QRegion const&, QPoint const&, int, QPainter*, QWidgetBackingStore*) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#14 0x00007f81313612f9 in QWidgetBackingStore::doSync() () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#15 0x00007f8131361d9e in QWidgetBackingStore::sync(QWidget*, QRegion const&) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#16 0x00007f81313b0593 in QWidgetWindow::event(QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#17 0x00007f8131354edc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#18 0x00007f813135a13e in QApplication::notify(QObject*, QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Widgets.so.5
#19 0x00007f813921dc09 in KWin::Application::notify (this=0x7fff5f161f40, o=0x12facd0, e=0x7fff5f161d40) at /opt/kf5/src/kde/workspace/kwin/main.cpp:344
#20 0x00007f813069dcd3 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Core.so.5
#21 0x00007f8130be1ffc in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Gui.so.5
#22 0x00007f8130be2b75 in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) () from /opt/qt/5.3/qtbase/lib/libQt5Gui.so.5
#23 0x00007f8130bc957f in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /opt/qt/5.3/qtbase/lib/libQt5Gui.so.5
#24 0x00007f812518c3b6 in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /opt/qt/5.3/qtbase/plugins/platforms/libqxcb.so
#25 0x00007f813069b832 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /opt/qt/5.3/qtbase/lib/libQt5Core.so.5
#26 0x00007f81306a2e8d in QCoreApplication::exec() () from /opt/qt/5.3/qtbase/lib/libQt5Core.so.5
#27 0x00007f813921f32f in kdemain (argc=1, argv=0x7fff5f1625a8) at /opt/kf5/src/kde/workspace/kwin/main.cpp:554
#28 0x0000000000400ce8 in main (argc=1, argv=0x7fff5f1625a8) at /opt/kf5/build/kde/workspace/kwin/kwin_dummy.cpp:3