Bug 349174

Application: kwin_x11 (5.2.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-20-generic x86_64
Distribution: Ubuntu 15.04

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

I was using Konsole and wanted to switch to Firefox with the <Alt>+<Tab> and KWin crashed.

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 0x7fb3d849f800 (LWP 1359))]

Thread 3 (Thread 0x7fb3baffd700 (LWP 1389)):
#0  0x00007fb3d7f62743 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fb3d67ac101 in qt_safe_select (nfds=16, fdread=fdread@entry=0x7fb3b0000a78, fdwrite=fdwrite@entry=0x7fb3b0000d08, fdexcept=fdexcept@entry=0x7fb3b0000f98, orig_timeout=orig_timeout@entry=0x0) at kernel/qcore_unix.cpp:75
#2  0x00007fb3d67adcd2 in select (timeout=0x0, exceptfds=0x7fb3b0000f98, writefds=0x7fb3b0000d08, readfds=0x7fb3b0000a78, nfds=<optimized out>, this=0x7fb3b00008c0) at kernel/qeventdispatcher_unix.cpp:320
#3  QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7fb3b00008e0, flags=..., flags@entry=..., timeout=timeout@entry=0x0) at kernel/qeventdispatcher_unix.cpp:196
#4  0x00007fb3d67ae275 in QEventDispatcherUNIX::processEvents (this=0x7fb3b00008c0, flags=...) at kernel/qeventdispatcher_unix.cpp:607
#5  0x00007fb3d67553e2 in QEventLoop::exec (this=this@entry=0x7fb3baffcda0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fb3d6514b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007fb3d03c7f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8  0x00007fb3d6519b0e in QThreadPrivate::start (arg=0xdfd270) at thread/qthread_unix.cpp:337
#9  0x00007fb3cf5946aa in start_thread (arg=0x7fb3baffd700) at pthread_create.c:333
#10 0x00007fb3d7f6beed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fb3ab7fe700 (LWP 1411)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fb3d531e644 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007fb3d531e689 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007fb3cf5946aa in start_thread (arg=0x7fb3ab7fe700) at pthread_create.c:333
#4  0x00007fb3d7f6beed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fb3d849f800 (LWP 1359)):
[KCrash Handler]
#6  QScreen::handle (this=0x0) at kernel/qscreen.cpp:85
#7  0x00007fb3c31cf545 in QXcbWindow::QXcbWindow (this=0x20f5220, window=0x1c26480) at qxcbwindow.cpp:260
#8  0x00007fb3c31bc5c1 in QXcbIntegration::createPlatformWindow (this=<optimized out>, window=0x1c26480) at qxcbintegration.cpp:194
#9  0x00007fb3d6aa9786 in QWindowPrivate::create (this=0x1bb32f0, recursive=recursive@entry=false) at kernel/qwindow.cpp:395
#10 0x00007fb3d6aa997b in QWindow::create (this=this@entry=0x1c26480) at kernel/qwindow.cpp:539
#11 0x00007fb3d6aa9b28 in QWindow::winId (this=0x1c26480) at kernel/qwindow.cpp:558
#12 0x00007fb3213b7b50 in PlasmaQuick::DialogPrivate::updateInputShape (this=0x1bb4800) at ../../../src/plasmaquick/dialog.cpp:542
#13 0x00007fb3d67889c9 in QMetaObject::activate (sender=sender@entry=0x1c26480, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=12, argv=argv@entry=0x7fff7b803940) at kernel/qobject.cpp:3716
#14 0x00007fb3d6789057 in QMetaObject::activate (sender=sender@entry=0x1c26480, m=m@entry=0x7fb3d6ef0b80 <QWindow::staticMetaObject>, local_signal_index=local_signal_index@entry=12, argv=argv@entry=0x7fff7b803940) at kernel/qobject.cpp:3582
#15 0x00007fb3d6aa91c2 in QWindow::visibleChanged (this=this@entry=0x1c26480, _t1=_t1@entry=true) at .moc/moc_qwindow.cpp:710
#16 0x00007fb3d6aac4b7 in QWindow::setVisible (this=this@entry=0x1c26480, visible=visible@entry=true) at kernel/qwindow.cpp:471
#17 0x00007fb3213b7a00 in PlasmaQuick::Dialog::setVisible (this=this@entry=0x1c26480, visible=<optimized out>) at ../../../src/plasmaquick/dialog.cpp:1225
#18 0x00007fb3213bc05a in PlasmaQuick::Dialog::qt_metacall (this=0x1c26480, _c=QMetaObject::WriteProperty, _id=9, _a=0x7fff7b803ab0) at ./moc_dialog.cpp:376
#19 0x00007fb3d033fb7f in QQmlPropertyPrivate::write(QObject*, QQmlPropertyData const&, QVariant const&, QQmlContextData*, QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#20 0x00007fb3d03415fb in QQmlPropertyPrivate::writeValueProperty(QObject*, QQmlPropertyData const&, QVariant const&, QQmlContextData*, QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#21 0x00007fb3d0341d31 in QQmlPropertyPrivate::writeBinding(QObject*, QQmlPropertyData const&, QQmlContextData*, QQmlJavaScriptExpression*, QV4::ValueRef, bool, QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#22 0x00007fb3d03b651c in QQmlBinding::update(QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#23 0x00007fb3d03b6c7e in QQmlBinding::expressionChanged(QQmlJavaScriptExpression*) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#24 0x00007fb3d0390497 in QQmlNotifier::emitNotify(QQmlNotifierEndpoint*, void**) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#25 0x00007fb3d032d10c in QQmlData::signalEmitted(QAbstractDeclarativeData*, QObject*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#26 0x00007fb3d6788141 in QMetaObject::activate (sender=0xe33710, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3603
#27 0x00007fb3d6789057 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7fb3d7e593e0 <KWin::TabBox::SwitcherItem::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3582
#28 0x00007fb3d7bca750 in KWin::TabBox::SwitcherItem::visibleChanged (this=<optimized out>) at moc_switcheritem.cpp:244
#29 0x00007fb3d7babd6f in KWin::TabBox::SwitcherItem::setVisible (this=<optimized out>, visible=visible@entry=true) at ../tabbox/switcheritem.cpp:75
#30 0x00007fb3d7baf501 in KWin::TabBox::TabBoxHandlerPrivate::show (this=<optimized out>) at ../tabbox/tabboxhandler.cpp:333
#31 0x00007fb3d7baf6c9 in KWin::TabBox::TabBoxHandler::show (this=0xcd4860) at ../tabbox/tabboxhandler.cpp:371
#32 0x00007fb3d7ba1b57 in KWin::TabBox::TabBox::show (this=<optimized out>) at ../tabbox/tabbox.cpp:725
#33 0x00007fb3d7bcc065 in KWin::TabBox::TabBox::qt_static_metacall (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at moc_tabbox.cpp:174
#34 0x00007fb3d67889c9 in QMetaObject::activate (sender=sender@entry=0xcce028, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3716
#35 0x00007fb3d6789057 in QMetaObject::activate (sender=sender@entry=0xcce028, m=m@entry=0x7fb3d69b2580 <QTimer::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3582
#36 0x00007fb3d6808610 in QTimer::timeout (this=this@entry=0xcce028) at .moc/moc_qtimer.cpp:192
#37 0x00007fb3d6796918 in QTimer::timerEvent (this=0xcce028, e=<optimized out>) at kernel/qtimer.cpp:247
#38 0x00007fb3d67896f3 in QObject::event (this=0xcce028, e=<optimized out>) at kernel/qobject.cpp:1267
#39 0x00007fb3d7061b2c in QApplicationPrivate::notify_helper (this=0xc51e50, receiver=0xcce028, e=0x7fff7b804490) at kernel/qapplication.cpp:3720
#40 0x00007fb3d7067000 in QApplication::notify (this=0x7fff7b8046d0, receiver=0xcce028, e=0x7fff7b804490) at kernel/qapplication.cpp:3503
#41 0x00007fb3d6757c2b in QCoreApplication::notifyInternal (this=0x7fff7b8046d0, receiver=0xcce028, event=event@entry=0x7fff7b804490) at kernel/qcoreapplication.cpp:935
#42 0x00007fb3d67afae5 in sendEvent (event=0x7fff7b804490, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#43 QTimerInfoList::activateTimers (this=0xc874a8) at kernel/qtimerinfo_unix.cpp:635
#44 0x00007fb3d67ad6a0 in QEventDispatcherUNIX::activateTimers (this=this@entry=0xc81400) at kernel/qeventdispatcher_unix.cpp:549
#45 0x00007fb3d67ae243 in QEventDispatcherUNIX::processEvents (this=0xc81400, flags=flags@entry=...) at kernel/qeventdispatcher_unix.cpp:611
#46 0x00007fb3c321196d in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
#47 0x00007fb3d67553e2 in QEventLoop::exec (this=this@entry=0x7fff7b8045f0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#48 0x00007fb3d675d02c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#49 0x00007fb3d6a9c31c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#50 0x00007fb3d705d7a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#51 0x00007fb3d82338c3 in kdemain (argc=1, argv=0x7fff7b804828) at ../main_x11.cpp:294
#52 0x00007fb3d7e85a40 in __libc_start_main (main=0x400790 <main(int, char**)>, argc=3, argv=0x7fff7b804828, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff7b804818) at libc-start.c:289
#53 0x00000000004007c9 in _start ()

Reported using DrKonqi