Application: kwin_x11 (5.16.3)

Qt Version: 5.12.2
Frameworks Version: 5.59.0
Operating System: Linux 5.0.0-21-generic x86_64
Distribution: Ubuntu 19.04

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

i close virtual display, then system write that kwin crashes

-- 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 0x7f04c1aa9880 (LWP 13904))]

Thread 7 (Thread 0x7f0429b6c700 (LWP 13731)):
#0  0x00007f04c99e7826 in __GI_ppoll (fds=0x7f041c003918, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f04c8554041 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f04c85554b9 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f04c85035bb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f04c834e2c6 in QThread::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f04c6cabef5 in  () at /lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007f04c834f612 in  () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f04c74ef182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#8  0x00007f04c99f3b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7f0422209700 (LWP 14443)):
#0  0x00007f04c74f53bb in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55a4122abb28) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f04c74f53bb in __pthread_cond_wait_common (abstime=0x0, mutex=0x55a4122abad8, cond=0x55a4122abb00) at pthread_cond_wait.c:502
#2  0x00007f04c74f53bb in __pthread_cond_wait (cond=0x55a4122abb00, mutex=0x55a4122abad8) at pthread_cond_wait.c:655
#3  0x00007f04227a436b in  () at /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007f04227a40d7 in  () at /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007f04c74ef182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007f04c99f3b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7f04b8a9e700 (LWP 14201)):
#0  0x00007f04c74f53bb in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7f04c7ee5fb8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f04c74f53bb in __pthread_cond_wait_common (abstime=0x0, mutex=0x7f04c7ee5f68, cond=0x7f04c7ee5f90) at pthread_cond_wait.c:502
#2  0x00007f04c74f53bb in __pthread_cond_wait (cond=0x7f04c7ee5f90, mutex=0x7f04c7ee5f68) at pthread_cond_wait.c:655
#3  0x00007f04c7defeca in  () at /lib/x86_64-linux-gnu/libQt5Script.so.5
#4  0x00007f04c7defee9 in  () at /lib/x86_64-linux-gnu/libQt5Script.so.5
#5  0x00007f04c74ef182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007f04c99f3b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7f04b9d01700 (LWP 14061)):
#0  0x00007f04c99e7826 in __GI_ppoll (fds=0x7f04b0000d28, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f04c8554041 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f04c85554b9 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f04c85035bb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f04c834e2c6 in QThread::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f04c6cabef5 in  () at /lib/x86_64-linux-gnu/libQt5Qml.so.5
#6  0x00007f04c834f612 in  () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f04c74ef182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#8  0x00007f04c99f3b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f04bbf59700 (LWP 13933)):
#0  0x00007f04c99e7826 in __GI_ppoll (fds=0x7f04b400b1d8, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1  0x00007f04c8554041 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007f04c85554b9 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007f04c85035bb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f04c834e2c6 in QThread::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f04c6708565 in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#6  0x00007f04c834f612 in  () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f04c74ef182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#8  0x00007f04c99f3b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f04c0eb0700 (LWP 13918)):
#0  0x00007f04c99e7729 in __GI___poll (fds=0x7f04c0eafc28, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f04c8274917 in  () at /lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f04c827653a in xcb_wait_for_event () at /lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f04c13cf6a8 in  () at /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007f04c834f612 in  () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f04c74ef182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007f04c99f3b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f04c1aa9880 (LWP 13904)):
[KCrash Handler]
#6  0x00007f04c970072f in KWin::Workspace::clientArea(KWin::clientAreaOption, int, int) const () at /lib/x86_64-linux-gnu/libkwin.so.5
#7  0x00007f04c970a413 in KWin::AbstractClient::checkWorkspacePosition(QRect, int, QRect) () at /lib/x86_64-linux-gnu/libkwin.so.5
#8  0x00007f04c964b041 in KWin::Workspace::sendClientToDesktop(KWin::AbstractClient*, int, bool) () at /lib/x86_64-linux-gnu/libkwin.so.5
#9  0x00007f04c964b58e in  () at /lib/x86_64-linux-gnu/libkwin.so.5
#10 0x00007f04c852e563 in QMetaObject::activate(QObject*, int, int, void**) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#11 0x00007f04c9806e22 in KWin::VirtualDesktopManager::desktopRemoved(KWin::VirtualDesktop*) () at /lib/x86_64-linux-gnu/libkwin.so.5
#12 0x00007f04c9759688 in KWin::VirtualDesktopManager::removeVirtualDesktop(QByteArray const&) () at /lib/x86_64-linux-gnu/libkwin.so.5
#13 0x00007f04c965b410 in  () at /lib/x86_64-linux-gnu/libkwin.so.5
#14 0x00007f04c9800751 in  () at /lib/x86_64-linux-gnu/libkwin.so.5
#15 0x00007f04c9800e4b in  () at /lib/x86_64-linux-gnu/libkwin.so.5
#16 0x00007f04c6713dba in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#17 0x00007f04c6717b89 in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#18 0x00007f04c67181d6 in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#19 0x00007f04c671a90e in  () at /lib/x86_64-linux-gnu/libQt5DBus.so.5
#20 0x00007f04c852eca2 in QObject::event(QEvent*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#21 0x00007f04c8ecc551 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#22 0x00007f04c8ed3930 in QApplication::notify(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#23 0x00007f04c85048e9 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x00007f04c8507927 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#25 0x00007f04c855532b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#26 0x00007f04c13d0a0e in  () at /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#27 0x00007f04c85035bb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#28 0x00007f04c850b5e2 in QCoreApplication::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5
#29 0x00007f04c9acadf8 in kdemain () at /lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so
#30 0x00007f04c98fcb6b in __libc_start_main (main=0x55a410e38050, argc=3, argv=0x7ffeaa0cdc78, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffeaa0cdc68) at ../csu/libc-start.c:308
#31 0x000055a410e3808a in _start ()
[Inferior 1 (process 13904) detached]

Reported using DrKonqi