Application: kwin_x11 (5.12.3)

Qt Version: 5.10.1
Frameworks Version: 5.44.0
Operating System: Linux 4.16.0-0.rc5.git0.2.fc28.x86_64 x86_64
Distribution: "Fedora release 28 (Twenty Eight)"

-- Information about the crash:
- What I was doing when the application crashed:
hit the top-left corner multiple times. looks like a race condition.

- Custom settings of the application:
kwin_x11, kwin-5.12.3-2.fc28.x86_64 (fedora beta)

The crash can be reproduced sometimes.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f90b1412940 (LWP 20710))]

Thread 5 (Thread 0x7f90790dc700 (LWP 20749)):
#0  0x00007f90a77dda46 in ppoll () at /lib64/libc.so.6
#1  0x00007f90a86a5e55 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /lib64/libQt5Core.so.5
#2  0x00007f90a86a7159 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#3  0x00007f90a865812b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#4  0x00007f90a84a69c6 in QThread::exec() () at /lib64/libQt5Core.so.5
#5  0x00007f90af60d489 in QQmlThreadPrivate::run() () at /lib64/libQt5Qml.so.5
#6  0x00007f90a84ab11d in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#7  0x00007f90aa92a564 in start_thread () at /lib64/libpthread.so.0
#8  0x00007f90a77e833f in clone () at /lib64/libc.so.6

Thread 4 (Thread 0x7f9067fff700 (LWP 20722)):
#0  0x00007f90aa9304fc in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f90b06829f8 in QTWTF::TCMalloc_PageHeap::scavengerThread() () at /lib64/libQt5Script.so.5
#2  0x00007f90b0682a63 in  () at /lib64/libQt5Script.so.5
#3  0x00007f90aa92a564 in start_thread () at /lib64/libpthread.so.0
#4  0x00007f90a77e833f in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7f907b7cb700 (LWP 20719)):
#0  0x00007f90a77dda46 in ppoll () at /lib64/libc.so.6
#1  0x00007f90a86a5e55 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /lib64/libQt5Core.so.5
#2  0x00007f90a86a7159 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#3  0x00007f90a865812b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#4  0x00007f90a84a69c6 in QThread::exec() () at /lib64/libQt5Core.so.5
#5  0x00007f90af60d489 in QQmlThreadPrivate::run() () at /lib64/libQt5Qml.so.5
#6  0x00007f90a84ab11d in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#7  0x00007f90aa92a564 in start_thread () at /lib64/libpthread.so.0
#8  0x00007f90a77e833f in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7f908a22b700 (LWP 20715)):
#0  0x00007f90a77dda46 in ppoll () at /lib64/libc.so.6
#1  0x00007f90a86a5e55 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /lib64/libQt5Core.so.5
#2  0x00007f90a86a7159 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#3  0x00007f90a865812b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#4  0x00007f90a84a69c6 in QThread::exec() () at /lib64/libQt5Core.so.5
#5  0x00007f90b14d2299 in QDBusConnectionManager::run() () at /lib64/libQt5DBus.so.5
#6  0x00007f90a84ab11d in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#7  0x00007f90aa92a564 in start_thread () at /lib64/libpthread.so.0
#8  0x00007f90a77e833f in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7f90b1412940 (LWP 20710)):
[KCrash Handler]
#6  0x00007f90b0defefc in QVector<int>::contains(int const&) const [clone .isra.139] () at /lib64/libkwin.so.5
#7  0x00007f90b0df4016 in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) () at /lib64/libkwin.so.5
#8  0x00007f90a8656c2c in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /lib64/libQt5Core.so.5
#9  0x00007f908c99ac84 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /lib64/libQt5XcbQpa.so.5
#10 0x00007f908c99b843 in QXcbConnection::processXcbEvents() () at /lib64/libQt5XcbQpa.so.5
#11 0x00007f90a8682a26 in QObject::event(QEvent*) () at /lib64/libQt5Core.so.5
#12 0x00007f90a8f20e95 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib64/libQt5Widgets.so.5
#13 0x00007f90a8f2883a in QApplication::notify(QObject*, QEvent*) () at /lib64/libQt5Widgets.so.5
#14 0x00007f90a8659376 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /lib64/libQt5Core.so.5
#15 0x00007f90a865c09b in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib64/libQt5Core.so.5
#16 0x00007f90a86a6fcf in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#17 0x00007f908ca27321 in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5XcbQpa.so.5
#18 0x00007f90a865812b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#19 0x00007f90a86605b6 in QCoreApplication::exec() () at /lib64/libQt5Core.so.5
#20 0x00007f90b11e193f in kdemain () at /lib64/libkdeinit5_kwin_x11.so
#21 0x00007f90a77111bb in __libc_start_main () at /lib64/libc.so.6
#22 0x000055afee40ecda in _start ()

Possible duplicates by query: bug 390247, bug 389936, bug 389542, bug 389201, bug 387289.

Reported using DrKonqi