Application: kwin_x11 (5.11.3)

Qt Version: 5.9.3
Frameworks Version: 5.40.0
Operating System: Linux 4.13.12-1-ARCH x86_64
Distribution (Platform): Archlinux Packages

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

1) Press and <Alt> + <Tab> to open the application switcher.
2) Let go of <Tab>, but keep holding <Alt>.
3) Press <Esc> to close the application switcher.
4) Kwin crashes.

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 0x7f1e9fa20840 (LWP 18821))]

Thread 6 (Thread 0x7f1e61a97700 (LWP 18835)):
#0  0x00007f1e9834b38d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f1e9b8feef7 in  () at /usr/lib/libQt5Script.so.5
#2  0x00007f1e9b8fef39 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007f1e9834508a in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f1e9f3b547f in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7f1e62c9e700 (LWP 18833)):
#0  0x00007f1e9834b38d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f1e6c739ddc in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#2  0x00007f1e6c739ce8 in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#3  0x00007f1e9834508a in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f1e9f3b547f in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7f1e6349f700 (LWP 18832)):
#0  0x00007f1e9834b38d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f1e6c739ddc in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#2  0x00007f1e6c739ce8 in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#3  0x00007f1e9834508a in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f1e9f3b547f in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7f1e7cdae700 (LWP 18830)):
#0  0x00007f1e9f3ab076 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f1e9c9e0d23 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f1e9c9e24bf in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f1e9c98899b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f1e9c7a127e in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f1e96e4ccf9 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007f1e9c7a61cb in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f1e9834508a in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f1e9f3b547f in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7f1e7fb59700 (LWP 18827)):
#0  0x00007f1e9f3ab076 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f1e9c9e0d23 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f1e9c9e24bf in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f1e9c98899b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f1e9c7a127e in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f1e95fee376 in  () at /usr/lib/libQt5DBus.so.5
#6  0x00007f1e9c7a61cb in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f1e9834508a in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f1e9f3b547f in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7f1e9fa20840 (LWP 18821)):
[KCrash Handler]
#5  0x00007f1e6ca7a664 in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#6  0x00007f1e6c85e61c in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#7  0x00007f1e6c641200 in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#8  0x00007f1e6c604ad8 in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#9  0x00007f1e6c60525f in  () at /usr/lib/xorg/modules/dri/r600_dri.so
#10 0x00007f1e974f87d7 in QSGBatchRenderer::Renderer::renderMergedBatch(QSGBatchRenderer::Batch const*) () at /usr/lib/libQt5Quick.so.5
#11 0x00007f1e974f9a76 in QSGBatchRenderer::Renderer::renderBatches() () at /usr/lib/libQt5Quick.so.5
#12 0x00007f1e974ff2ee in QSGBatchRenderer::Renderer::render() () at /usr/lib/libQt5Quick.so.5
#13 0x00007f1e974ef922 in QSGRenderer::renderScene(QSGBindable const&) () at /usr/lib/libQt5Quick.so.5
#14 0x00007f1e974efdec in QSGRenderer::renderScene(unsigned int) () at /usr/lib/libQt5Quick.so.5
#15 0x00007f1e9752afc0 in QSGDefaultRenderContext::renderNextFrame(QSGRenderer*, unsigned int) () at /usr/lib/libQt5Quick.so.5
#16 0x00007f1e975898a0 in QQuickWindowPrivate::renderSceneGraph(QSize const&) () at /usr/lib/libQt5Quick.so.5
#17 0x00007f1e9751d118 in  () at /usr/lib/libQt5Quick.so.5
#18 0x00007f1e97593f36 in QQuickWindow::event(QEvent*) () at /usr/lib/libQt5Quick.so.5
#19 0x00007f1dd0ab20f4 in PlasmaQuick::Dialog::event(QEvent*) () at /usr/lib/libKF5PlasmaQuick.so.5
#20 0x00007f1e9d6a7f5c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#21 0x00007f1e9d6afa36 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#22 0x00007f1e9c98a570 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#23 0x00007f1e9cef54d3 in QWindowPrivate::deliverUpdateRequest() () at /usr/lib/libQt5Gui.so.5
#24 0x00007f1e9cef59fb in QWindow::event(QEvent*) () at /usr/lib/libQt5Gui.so.5
#25 0x00007f1e97593ed6 in QQuickWindow::event(QEvent*) () at /usr/lib/libQt5Quick.so.5
#26 0x00007f1dd0ab20f4 in PlasmaQuick::Dialog::event(QEvent*) () at /usr/lib/libKF5PlasmaQuick.so.5
#27 0x00007f1e9d6a7f5c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#28 0x00007f1e9d6afa36 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#29 0x00007f1e9c98a570 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#30 0x00007f1e9c9e4628 in QTimerInfoList::activateTimers() () at /usr/lib/libQt5Core.so.5
#31 0x00007f1e9c9e2724 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#32 0x00007f1e871bface in  () at /usr/lib/libQt5XcbQpa.so.5
#33 0x00007f1e9c98899b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#34 0x00007f1e9c9919e8 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#35 0x00007f1e9f67f6e3 in kdemain () at /usr/lib/libkdeinit5_kwin_x11.so
#36 0x00007f1e9f2dff6a in __libc_start_main () at /usr/lib/libc.so.6
#37 0x0000560f28a947aa in _start ()

Reported using DrKonqi