Application: kwin_x11 (5.2.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-15-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
- What I was doing when the application crashed:
Using the Display Configuration tool in System Settings, disabled one output, enabled another and then applied.  The behaviour is the same whether I'm switching to external display or back to internal laptop screen.

I listed the reproducibility as "sometimes" but I think it's probably always.

- Unusual behavior I noticed:
KWin crashes (initiating the bug report tool) and also the displaid screen resolution is not correct until KWin is restarted.  Some areas of the screen are corrupted whilst other areas display part of what was formerly on the other screen.

The crash can be reproduced sometimes.

-- 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 0x7f4b52f5c800 (LWP 1595))]

Thread 4 (Thread 0x7f4b35432700 (LWP 1646)):
#0  0x00007f4b52a25743 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f4b5126f101 in qt_safe_select (nfds=16, fdread=fdread@entry=0x7f4b2c000a78, fdwrite=fdwrite@entry=0x7f4b2c000d08, fdexcept=fdexcept@entry=0x7f4b2c000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007f4b51270cd2 in select (timeout=0x0, exceptfds=0x7f4b2c000f98, writefds=0x7f4b2c000d08, readfds=0x7f4b2c000a78, nfds=<optimized out>, this=0x7f4b2c0008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f4b2c0008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007f4b51271275 in QEventDispatcherUNIX::processEvents (this=0x7f4b2c0008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007f4b512183e2 in QEventLoop::exec (this=this@entry=0x7f4b35431da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f4b50fd7b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f4b4ae8af65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f4b50fdcb0e in QThreadPrivate::start (arg=0x1c1ada0) at thread/qthread_unix.cpp:337
#9  0x00007f4b4a0576aa in start_thread (arg=0x7f4b35432700) at pthread_create.c:333
#10 0x00007f4b52a2eeed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f4b24d52700 (LWP 1658)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f4b4fde1644 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f4b4fde1689 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f4b4a0576aa in start_thread (arg=0x7f4b24d52700) at pthread_create.c:333
#4  0x00007f4b52a2eeed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f4b36677700 (LWP 10723)):
#0  0x00007f4b52a25743 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f4b5126f101 in qt_safe_select (nfds=12, fdread=fdread@entry=0x7f4b30000a78, fdwrite=fdwrite@entry=0x7f4b30000d08, fdexcept=fdexcept@entry=0x7f4b30000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007f4b51270cd2 in select (timeout=0x0, exceptfds=0x7f4b30000f98, writefds=0x7f4b30000d08, readfds=0x7f4b30000a78, nfds=<optimized out>, this=0x7f4b300008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7f4b300008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007f4b51271275 in QEventDispatcherUNIX::processEvents (this=0x7f4b300008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007f4b512183e2 in QEventLoop::exec (this=this@entry=0x7f4b36676da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f4b50fd7b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f4b4ae8af65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007f4b50fdcb0e in QThreadPrivate::start (arg=0x2892c50) at thread/qthread_unix.cpp:337
#9  0x00007f4b4a0576aa in start_thread (arg=0x7f4b36677700) at pthread_create.c:333
#10 0x00007f4b52a2eeed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f4b52f5c800 (LWP 1595)):
[KCrash Handler]
#6  QScreen::handle (this=0x0) at kernel/qscreen.cpp:85
#7  0x00007f4b3de06545 in QXcbWindow::QXcbWindow (this=0x28a4070, window=0x2c2a180) at qxcbwindow.cpp:260
#8  0x00007f4b3ddf35c1 in QXcbIntegration::createPlatformWindow (this=<optimized out>, window=0x2c2a180) at qxcbintegration.cpp:194
#9  0x00007f4b5156c786 in QWindowPrivate::create (this=0x2c2b610, recursive=recursive@entry=false) at kernel/qwindow.cpp:395
#10 0x00007f4b5156c97b in QWindow::create (this=this@entry=0x2c2a180) at kernel/qwindow.cpp:539
#11 0x00007f4b5156cb28 in QWindow::winId (this=0x2c2a180) at kernel/qwindow.cpp:558
#12 0x00007f4b52608c9f in KWin::AbstractThumbnailItem::findParentEffectWindow (this=0x2dd7bc0) at ../thumbnailitem.cpp:79
#13 0x00007f4b52608e69 in KWin::AbstractThumbnailItem::effectWindowAdded (this=0x2dd7bc0) at ../thumbnailitem.cpp:90
#14 0x00007f4b52693125 in KWin::AbstractThumbnailItem::qt_static_metacall (_o=0x0, _c=QMetaObject::ResetProperty, _id=28273744, _a=0x7f4b52cecc00 <main_arena>) at moc_thumbnailitem.cpp:130
#15 0x00007f4b5124b9c9 in QMetaObject::activate (sender=0x2249590, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=5, argv=argv@entry=0x7ffec7104cd0) at kernel/qobject.cpp:3716
#16 0x00007f4b5124c057 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7f4b50a09ac0 <KWin::EffectsHandler::staticMetaObject>, local_signal_index=local_signal_index@entry=5, argv=argv@entry=0x7ffec7104cd0) at kernel/qobject.cpp:3582
#17 0x00007f4b507fafb2 in KWin::EffectsHandler::windowAdded (this=<optimized out>, _t1=0x2fa70f0) at moc_kwineffects.cpp:1195
#18 0x00007f4b5124b35a in call (a=0x7ffec7104e10, r=0x2249590, this=0x2e21bc0) at ../../include/QtCore/../../src/corelib/kernel/qobject_impl.h:124
#19 QMetaObject::activate (sender=sender@entry=0x2f32e70, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=7, argv=argv@entry=0x7ffec7104e10) at kernel/qobject.cpp:3702
#20 0x00007f4b5124c057 in QMetaObject::activate (sender=sender@entry=0x2f32e70, m=m@entry=0x7f4b5291c2e0 <KWin::Toplevel::staticMetaObject>, local_signal_index=local_signal_index@entry=7, argv=argv@entry=0x7ffec7104e10) at kernel/qobject.cpp:3582
#21 0x00007f4b5268dfc2 in KWin::Toplevel::windowShown (this=this@entry=0x2f32e70, _t1=_t1@entry=0x2f32e70) at moc_toplevel.cpp:656
#22 0x00007f4b525d4ddf in KWin::Toplevel::setReadyForPainting (this=this@entry=0x2f32e70) at ../toplevel.cpp:245
#23 0x00007f4b5258732f in KWin::Client::syncEvent (this=0x2f32e70, e=<optimized out>) at ../events.cpp:1561
#24 0x00007f4b5258a301 in KWin::Workspace::workspaceEvent (this=0x1ae89a0, e=0x7f4b38003fc0) at ../events.cpp:556
#25 0x00007f4b51217510 in QAbstractEventDispatcher::filterNativeEvent (this=this@entry=0x1a68260, eventType=..., message=message@entry=0x7f4b38003fc0, result=result@entry=0x7ffec7104fa8) at kernel/qabstracteventdispatcher.cpp:460
#26 0x00007f4b3ddf102d in QXcbConnection::handleXcbEvent (this=this@entry=0x1a34b10, event=event@entry=0x7f4b38003fc0) at qxcbconnection.cpp:863
#27 0x00007f4b3ddf24bb in QXcbConnection::processXcbEvents (this=0x1a34b10) at qxcbconnection.cpp:1303
#28 0x00007f4b5124c73a in QObject::event (this=0x1a34b10, e=<optimized out>) at kernel/qobject.cpp:1245
#29 0x00007f4b51b24b2c in QApplicationPrivate::notify_helper (this=0x1a2de30, receiver=0x1a34b10, e=0x7f4b38007a90) at kernel/qapplication.cpp:3720
#30 0x00007f4b51b2a000 in QApplication::notify (this=0x7ffec7105690, receiver=0x1a34b10, e=0x7f4b38007a90) at kernel/qapplication.cpp:3503
#31 0x00007f4b5121ac2b in QCoreApplication::notifyInternal (this=0x7ffec7105690, receiver=0x1a34b10, event=event@entry=0x7f4b38007a90) at kernel/qcoreapplication.cpp:935
#32 0x00007f4b5121cc9b in sendEvent (event=0x7f4b38007a90, 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=0x1a1e2f0) at kernel/qcoreapplication.cpp:1552
#34 0x00007f4b51271112 in QEventDispatcherUNIX::processEvents (this=0x1a68260, flags=flags@entry=...) at kernel/qeventdispatcher_unix.cpp:579
#35 0x00007f4b3de4896d in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
#36 0x00007f4b512183e2 in QEventLoop::exec (this=this@entry=0x7ffec71055b0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#37 0x00007f4b5122002c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#38 0x00007f4b5155f31c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#39 0x00007f4b51b207a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#40 0x00007f4b52cf68c3 in kdemain (argc=1, argv=0x7ffec71057e8) at ../main_x11.cpp:294
#41 0x00007f4b52948a40 in __libc_start_main (main=0x400790 <main(int, char**)>, argc=1, argv=0x7ffec71057e8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffec71057d8) at libc-start.c:289
#42 0x00000000004007c9 in _start ()

Reported using DrKonqi