Application: kwin_x11 (5.2.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-12-generic x86_64
Distribution: Ubuntu Vivid Vervet (development branch)

-- Information about the crash:
I first tried to unplug monitor by pulling the HDMI cable. Nothing happened. Then I plugged the cable back in, and went to screen settings to enable laptop screen and disable external screen. I accepted and after that I pulled the cable again. Then kWin crached...

-- 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 0x7f1192a5d800 (LWP 1480))]

Thread 3 (Thread 0x7f1174949700 (LWP 1515)):
#0  0x00007f119252e743 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f1190d7a101 in qt_safe_select (nfds=18, fdread=fdread@entry=0x7f116c000a78, fdwrite=fdwrite@entry=0x7f116c000d08, fdexcept=fdexcept@entry=0x7f116c000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007f1190d7bcd2 in select (timeout=0x0, exceptfds=0x7f116c000f98, writefds=0x7f116c000d08, readfds=0x7f116c000a78, nfds=<optimized out>, this=0x7f116c0008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f116c0008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007f1190d7c275 in QEventDispatcherUNIX::processEvents (this=0x7f116c0008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007f1190d233e2 in QEventLoop::exec (this=this@entry=0x7f1174948da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f1190ae2b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f118a997f45 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f1190ae7b0e in QThreadPrivate::start (arg=0x16d76b0) at thread/qthread_unix.cpp:337
#9  0x00007f1189b646aa in start_thread (arg=0x7f1174949700) at pthread_create.c:333
#10 0x00007f1192537eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f115ffff700 (LWP 1540)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f118f8ec644 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f118f8ec689 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f1189b646aa in start_thread (arg=0x7f115ffff700) at pthread_create.c:333
#4  0x00007f1192537eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f1192a5d800 (LWP 1480)):
[KCrash Handler]
#6  QScreen::handle (this=0x0) at kernel/qscreen.cpp:85
#7  0x00007f117d7a6545 in QXcbWindow::QXcbWindow (this=0x24a7de0, window=0x2701800) at qxcbwindow.cpp:260
#8  0x00007f117d7935c1 in QXcbIntegration::createPlatformWindow (this=<optimized out>, window=0x2701800) at qxcbintegration.cpp:194
#9  0x00007f1191077786 in QWindowPrivate::create (this=0x27012f0, recursive=recursive@entry=false) at kernel/qwindow.cpp:395
#10 0x00007f119107797b in QWindow::create (this=this@entry=0x2701800) at kernel/qwindow.cpp:539
#11 0x00007f1191077b28 in QWindow::winId (this=0x2701800) at kernel/qwindow.cpp:558
#12 0x00007f1192111c9f in KWin::AbstractThumbnailItem::findParentEffectWindow (this=0x2d74090) at ../thumbnailitem.cpp:79
#13 0x00007f1192111e69 in KWin::AbstractThumbnailItem::effectWindowAdded (this=0x2d74090) at ../thumbnailitem.cpp:90
#14 0x00007f119219c125 in KWin::AbstractThumbnailItem::qt_static_metacall (_o=0x0, _c=QMetaObject::ResetProperty, _id=45054944, _a=0x7f11927f5c00 <main_arena>) at moc_thumbnailitem.cpp:130
#15 0x00007f1190d569c9 in QMetaObject::activate (sender=0x238ab00, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=5, argv=argv@entry=0x7ffca8a58df0) at kernel/qobject.cpp:3716
#16 0x00007f1190d57057 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7f1190514ac0 <KWin::EffectsHandler::staticMetaObject>, local_signal_index=local_signal_index@entry=5, argv=argv@entry=0x7ffca8a58df0) at kernel/qobject.cpp:3582
#17 0x00007f1190305fb2 in KWin::EffectsHandler::windowAdded (this=<optimized out>, _t1=0x2062d20) at moc_kwineffects.cpp:1195
#18 0x00007f1190d5635a in call (a=0x7ffca8a58f30, r=0x238ab00, this=0x25c3060) at ../../include/QtCore/../../src/corelib/kernel/qobject_impl.h:124
#19 QMetaObject::activate (sender=sender@entry=0x2c34940, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=7, argv=argv@entry=0x7ffca8a58f30) at kernel/qobject.cpp:3702
#20 0x00007f1190d57057 in QMetaObject::activate (sender=sender@entry=0x2c34940, m=m@entry=0x7f11924252e0 <KWin::Toplevel::staticMetaObject>, local_signal_index=local_signal_index@entry=7, argv=argv@entry=0x7ffca8a58f30) at kernel/qobject.cpp:3582
#21 0x00007f1192196fc2 in KWin::Toplevel::windowShown (this=this@entry=0x2c34940, _t1=_t1@entry=0x2c34940) at moc_toplevel.cpp:656
#22 0x00007f11920ddddf in KWin::Toplevel::setReadyForPainting (this=this@entry=0x2c34940) at ../toplevel.cpp:245
#23 0x00007f119209032f in KWin::Client::syncEvent (this=0x2c34940, e=<optimized out>) at ../events.cpp:1561
#24 0x00007f1192093301 in KWin::Workspace::workspaceEvent (this=0x156b4c0, e=0x7f1178001ec0) at ../events.cpp:556
#25 0x00007f1190d22510 in QAbstractEventDispatcher::filterNativeEvent (this=this@entry=0x1500660, eventType=..., message=message@entry=0x7f1178001ec0, result=result@entry=0x7ffca8a590c8) at kernel/qabstracteventdispatcher.cpp:460
#26 0x00007f117d79102d in QXcbConnection::handleXcbEvent (this=this@entry=0x14d1ad0, event=event@entry=0x7f1178001ec0) at qxcbconnection.cpp:863
#27 0x00007f117d7924bb in QXcbConnection::processXcbEvents (this=0x14d1ad0) at qxcbconnection.cpp:1303
#28 0x00007f1190d5773a in QObject::event (this=0x14d1ad0, e=<optimized out>) at kernel/qobject.cpp:1245
#29 0x00007f119162fb2c in QApplicationPrivate::notify_helper (this=0x14cad40, receiver=0x14d1ad0, e=0x7f1178002080) at kernel/qapplication.cpp:3720
#30 0x00007f1191635000 in QApplication::notify (this=0x7ffca8a597b0, receiver=0x14d1ad0, e=0x7f1178002080) at kernel/qapplication.cpp:3503
#31 0x00007f1190d25c2b in QCoreApplication::notifyInternal (this=0x7ffca8a597b0, receiver=0x14d1ad0, event=event@entry=0x7f1178002080) at kernel/qcoreapplication.cpp:935
#32 0x00007f1190d27c9b in sendEvent (event=0x7f1178002080, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#33 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x14bb2f0) at kernel/qcoreapplication.cpp:1552
#34 0x00007f1190d7c112 in QEventDispatcherUNIX::processEvents (this=0x1500660, flags=flags@entry=...) at kernel/qeventdispatcher_unix.cpp:579
#35 0x00007f117d7e896d in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
#36 0x00007f1190d233e2 in QEventLoop::exec (this=this@entry=0x7ffca8a596d0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#37 0x00007f1190d2b02c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#38 0x00007f119106a31c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#39 0x00007f119162b7a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#40 0x00007f11927ff8c3 in kdemain (argc=1, argv=0x7ffca8a59908) at ../main_x11.cpp:294
#41 0x00007f1192451a40 in __libc_start_main (main=0x400790 <main(int, char**)>, argc=1, argv=0x7ffca8a59908, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffca8a598f8) at libc-start.c:289
#42 0x00000000004007c9 in _start ()

Reported using DrKonqi