Application: kwin_x11 (5.14.5)

Qt Version: 5.12.1
Frameworks Version: 5.54.0
Operating System: Linux 4.19.20-1-MANJARO x86_64
Distribution: "Arch Linux"

-- Information about the crash:
it happens when close all windows and try to open launcher

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fb53826e840 (LWP 1403))]

Thread 7 (Thread 0x7fb534f2b700 (LWP 1463)):
#0  0x00007fb5410bfd16 in ppoll () at /usr/lib/libc.so.6
#1  0x00007fb53fc66bab in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007fb53fc6808b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007fb53fc13b2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fb53fa57569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007fb53fa5896c in  () at /usr/lib/libQt5Core.so.5
#6  0x00007fb53ea38a9d in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007fb5410cab23 in clone () at /usr/lib/libc.so.6

Thread 6 (Thread 0x7fb516f3a700 (LWP 1417)):
#0  0x00007fb53ea3eafc in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fb53f54228c in  () at /usr/lib/libQt5Script.so.5
#2  0x00007fb53f5422a9 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007fb53ea38a9d in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007fb5410cab23 in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7fb5254cd700 (LWP 1415)):
#0  0x00007fb53ea3eafc in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fb525aa7c84 in  () at /usr/lib/dri/i965_dri.so
#2  0x00007fb525aa79a8 in  () at /usr/lib/dri/i965_dri.so
#3  0x00007fb53ea38a9d in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007fb5410cab23 in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7fb527fff700 (LWP 1413)):
#0  0x00007fb5410bfd16 in ppoll () at /usr/lib/libc.so.6
#1  0x00007fb53fc66bab in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007fb53fc6808b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007fb53fc13b2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fb53fa57569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007fb53e1f6969 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007fb53fa5896c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007fb53ea38a9d in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007fb5410cab23 in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7fb5366fe700 (LWP 1407)):
#0  0x00007fb5410bfd16 in ppoll () at /usr/lib/libc.so.6
#1  0x00007fb53fc66bab in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007fb53fc6808b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007fb53fc13b2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fb53fa57569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007fb53dc5bba6 in  () at /usr/lib/libQt5DBus.so.5
#6  0x00007fb53fa5896c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007fb53ea38a9d in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007fb5410cab23 in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7fb53770f700 (LWP 1405)):
#0  0x00007fb5410bfc21 in poll () at /usr/lib/libc.so.6
#1  0x00007fb53f97c630 in  () at /usr/lib/libxcb.so.1
#2  0x00007fb53f97e2db in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007fb537a1a949 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007fb53fa5896c in  () at /usr/lib/libQt5Core.so.5
#5  0x00007fb53ea38a9d in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007fb5410cab23 in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7fb53826e840 (LWP 1403)):
[KCrash Handler]
#6  0x00007fb540e0c8f2 in KWin::Workspace::clientArea(KWin::clientAreaOption, int, int) const () at /usr/lib/libkwin.so.5
#7  0x00007fb540df6c60 in KWin::Client::manage(unsigned int, bool) () at /usr/lib/libkwin.so.5
#8  0x00007fb540d661e0 in KWin::Workspace::createClient(unsigned int, bool) () at /usr/lib/libkwin.so.5
#9  0x00007fb540de25a8 in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) () at /usr/lib/libkwin.so.5
#10 0x00007fb53fc1295f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /usr/lib/libQt5Core.so.5
#11 0x00007fb5379efa92 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /usr/lib/libQt5XcbQpa.so.5
#12 0x00007fb5379f082e in QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5XcbQpa.so.5
#13 0x00007fb537a1bcce in  () at /usr/lib/libQt5XcbQpa.so.5
#14 0x00007fb53fc13b2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#15 0x00007fb53fc1be36 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#16 0x00007fb54119cb26 in kdemain () at /usr/lib/libkdeinit5_kwin_x11.so
#17 0x00007fb540ff3223 in __libc_start_main () at /usr/lib/libc.so.6
#18 0x000055b2cda5c05e in _start ()
[Inferior 1 (process 1403) detached]

Possible duplicates by query: bug 404090, bug 400977, bug 390247.

Reported using DrKonqi