Bug 430835

Summary: Crashes and display issues with mixed non-hiDPI / hiDPI multi-screen setup on wayland
Product: [Plasma] plasmashell Reporter: Leonard Lausen <leonard>
Component: generic-multiscreenAssignee: Aleix Pol <aleixpol>
Status: RESOLVED WORKSFORME    
Severity: normal CC: leonard, nate, plasma-bugs-null
Priority: NOR Keywords: wayland-only
Version First Reported In: 5.21.2   
Target Milestone: 1.0   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: desktop background issue when system tray on FHD screen
desktop background issue when system tray on FHD screen resolved after right click
system-tray and layout issue when system tray on 4K screen

Description Leonard Lausen 2020-12-26 18:57:50 UTC 
SUMMARY In Wayland Sessions, if the system tray was moved to an external screen, the plasma session and many KDE Applications will crash upon removal of the external screen. The crash occurs during a call to QMessageLogger.

STEPS TO REPRODUCE
1. Start a KDE Wayland Session
2. Add a second screen
3. Right click on the system tray and "Edit Panel"
4. Drag panel to the new screen and position it there
5. Disconnect second screen
6. Observe crash
7. Reconnect second srceen
8. Observe that plasmashell will start again

OBSERVED RESULT
plasmashell crashes. System tray disappears, tens of Dr Konqi windows show up for various KDE Background daemons.

EXPECTED RESULT
Panel moves to remaining screen.
No crash

SOFTWARE/OS VERSIONS
Operating System: Gentoo Linux
KDE Plasma Version: 5.20.4
KDE Frameworks Version: 5.77.0
Qt Version: 5.15.2
Kernel Version: 5.10.2-gentoo
OS Type: 64-bit
Processors: 4 × Intel® Core™ i7-7500U CPU @ 2.70GHz
Memory: 15.4 GiB of RAM
Graphics Processor: Mesa DRI Intel® HD Graphics 620

ADDITIONAL INFORMATION
Exemplar backtrace (all the backtraces look similar):

Application: KOrganizer Reminder Daemon (korgac), signal: Aborted

[KCrash Handler]
#4  0x00007fb88a5cddd1 in raise () from /lib64/libc.so.6
#5  0x00007fb88a5b7536 in abort () from /lib64/libc.so.6
#6  0x00007fb88aa69c97 in QMessageLogger::fatal(char const*, ...) const () from /usr/lib64/libQt5Core.so.5
#7  0x00007fb8880d0a50 in QtWaylandClient::QWaylandDisplay::checkError() const () from /usr/lib64/libQt5WaylandClient.so.5
#8  0x00007fb8880d1a53 in QtWaylandClient::QWaylandDisplay::flushRequests() () from /usr/lib64/libQt5WaylandClient.so.5
#9  0x00007fb88ac59b1c in void doActivate<false>(QObject*, int, void**) () from /usr/lib64/libQt5Core.so.5
#10 0x00007fb88ac5cd06 in QSocketNotifier::activated(QSocketDescriptor, QSocketNotifier::Type, QSocketNotifier::QPrivateSignal) () from /usr/lib64/libQt5Core.so.5
#11 0x00007fb88ac5d45b in QSocketNotifier::event(QEvent*) () from /usr/lib64/libQt5Core.so.5
#12 0x00007fb88b6046af in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#13 0x00007fb88ac2b018 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib64/libQt5Core.so.5
#14 0x00007fb88ac76e8e in socketNotifierSourceDispatch(_GSource*, int (*)(void*), void*) () from /usr/lib64/libQt5Core.so.5
#15 0x00007fb888863867 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#16 0x00007fb888863af0 in g_main_context_iterate.isra () from /usr/lib64/libglib-2.0.so.0
#17 0x00007fb888863b7f in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#18 0x00007fb88ac7645b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#19 0x00007fb88ac29a43 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#20 0x00007fb88ac314b0 in QCoreApplication::exec() () from /usr/lib64/libQt5Core.so.5
#21 0x000055daeb3e6a18 in main ()
[Inferior 1 (process 2324) detached]
Comment 1 Nate Graham 2021-02-25 21:26:58 UTC 
The apps/daemons crashing is a side effect of the session itself crashing. Any chance you have a backtrace for that?
Comment 2 Leonard Lausen 2021-03-07 21:41:45 UTC 
Thank you Nate for taking a look. I think the behavior has improved as of Plasma 5.21. The session/plasmashell does not crash anymore when removing the screen containing the system try. However, the multi-screen behavior is not completely stable yet either.

I observed two issues (please let me know if you'd rather have a new bug-report).
Further, in the first message I forgot to include that the main screen (laptop screen) of the setup is a 4K screen and scaled, whereas the external screen is a FHD screen and not scaled.

Issue 1: plasmashell can trigger qt5-wayland crash when moving the system tray between screens:

Application: Plasma (plasmashell), signal: Aborted

[KCrash Handler]
#4  0x00007fb5a0838d51 in raise () at /lib64/libc.so.6
#5  0x00007fb5a0822536 in abort () at /lib64/libc.so.6
#6  0x00007fb5a0c29c97 in qt_message_output(QtMsgType, QMessageLogContext const&, QString const&) [clone .cold] () at /usr/lib64/libQt5Core.so.5
#7  0x00007fb59f002a50 in QtWaylandClient::QWaylandDisplay::blockingReadEvents() () at /usr/lib64/libQt5WaylandClient.so.5
#8  0x00007fb59f002c3d in QtWaylandClient::QWaylandDisplay::dispatchQueueWhile(wl_event_queue*, std::function<bool ()>, int) () at /usr/lib64/libQt5WaylandClient.so.5
#9  0x00007fb59f00805e in QtWaylandClient::QWaylandWindow::waitForFrameSync(int) () at /usr/lib64/libQt5WaylandClient.so.5
#10 0x00007fb59c03e012 in QtWaylandClient::QWaylandGLContext::swapBuffers(QPlatformSurface*) () at /usr/lib64/qt5/plugins/wayland-graphics-integration-client/libqt-plugin-wayland-egl.so
#11 0x00007fb5a274377c in QSGRenderThread::syncAndRender(QImage*) () at /usr/lib64/libQt5Quick.so.5
#12 0x00007fb5a2743f47 in QSGRenderThread::run() () at /usr/lib64/libQt5Quick.so.5
#13 0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#14 0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#15 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 26 (Thread 0x7fb5791b0640 (LWP 67852) "QSGRenderThread"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a2741ad7 in QSGRenderThread::processEventsAndWaitForMore() () at /usr/lib64/libQt5Quick.so.5
#3  0x00007fb5a2743f89 in QSGRenderThread::run() () at /usr/lib64/libQt5Quick.so.5
#4  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#6  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 25 (Thread 0x7fb5737fe640 (LWP 65416) "Thread (pooled)"):
#1  0x00007fb5a0c66dc5 in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a0c64762 in QThreadPoolThread::run() () at /usr/lib64/libQt5Core.so.5
#3  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#4  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#5  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 24 (Thread 0x7fb4f3fff640 (LWP 3076) "QSGRenderThread"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a2741ad7 in QSGRenderThread::processEventsAndWaitForMore() () at /usr/lib64/libQt5Quick.so.5
#3  0x00007fb5a2743f89 in QSGRenderThread::run() () at /usr/lib64/libQt5Quick.so.5
#4  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#6  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 23 (Thread 0x7fb4fac9b640 (LWP 3047) "QSGRenderThread"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a2741ad7 in QSGRenderThread::processEventsAndWaitForMore() () at /usr/lib64/libQt5Quick.so.5
#3  0x00007fb5a2743f89 in QSGRenderThread::run() () at /usr/lib64/libQt5Quick.so.5
#4  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#6  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 22 (Thread 0x7fb511ffb640 (LWP 2700) "GlobalQueue[08]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a4df1 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#7  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#8  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#9  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#10 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 21 (Thread 0x7fb5127fc640 (LWP 2699) "GlobalQueue[07]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a4df1 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#7  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#8  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#9  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#10 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 20 (Thread 0x7fb512ffd640 (LWP 2698) "GlobalQueue[06]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a4df1 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#7  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#8  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#9  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#10 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 19 (Thread 0x7fb5137fe640 (LWP 2697) "GlobalQueue[05]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a4df1 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#7  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#8  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#9  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#10 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 18 (Thread 0x7fb513fff640 (LWP 2696) "GlobalQueue[04]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a4df1 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#7  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#8  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#9  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#10 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 17 (Thread 0x7fb520905640 (LWP 2695) "GlobalQueue[03]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a4df1 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#7  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#8  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#9  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#10 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 16 (Thread 0x7fb521106640 (LWP 2694) "GlobalQueue[02]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a4df1 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#7  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#8  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#9  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#10 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 15 (Thread 0x7fb521907640 (LWP 2693) "GlobalQueue[01]"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5702a11e0 in ThreadWeaver::Weaver::takeFirstAvailableJobOrSuspendOrWait(ThreadWeaver::Thread*, bool, bool, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#3  0x00007fb5702a4d96 in ThreadWeaver::WorkingHardState::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#4  0x00007fb5702a0332 in ThreadWeaver::Weaver::applyForWork(ThreadWeaver::Thread*, bool) () at /usr/lib64/libKF5ThreadWeaver.so.5
#5  0x00007fb5702a28fa in ThreadWeaver::Thread::run() () at /usr/lib64/libKF5ThreadWeaver.so.5
#6  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#7  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#8  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 14 (Thread 0x7fb54a9ee640 (LWP 2690) "QSGRenderThread"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a2741ad7 in QSGRenderThread::processEventsAndWaitForMore() () at /usr/lib64/libQt5Quick.so.5
#3  0x00007fb5a2743f89 in QSGRenderThread::run() () at /usr/lib64/libQt5Quick.so.5
#4  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#6  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 13 (Thread 0x7fb573fff640 (LWP 2689) "QSGRenderThread"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a2741ad7 in QSGRenderThread::processEventsAndWaitForMore() () at /usr/lib64/libQt5Quick.so.5
#3  0x00007fb5a2743f89 in QSGRenderThread::run() () at /usr/lib64/libQt5Quick.so.5
#4  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#6  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 12 (Thread 0x7fb55a129640 (LWP 2660) "KCupsConnection"):
#1  0x00007fb59f39937e in g_main_context_iterate.constprop () at /usr/lib64/libglib-2.0.so.0
#2  0x00007fb59f39949f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007fb5a0e364fb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007fb5a0de9ac3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb5a0c603d7 in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007fb55a656d18 in KCupsConnection::run() () at /usr/lib64/libkcupslib.so
#7  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#8  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#9  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 11 (Thread 0x7fb55b4b3640 (LWP 2659) "QThread"):
#1  0x00007fb59f39937e in g_main_context_iterate.constprop () at /usr/lib64/libglib-2.0.so.0
#2  0x00007fb59f39949f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007fb5a0e364fb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007fb5a0de9ac3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb5a0c603d7 in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#7  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#8  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 10 (Thread 0x7fb570c0d640 (LWP 2599) "SessionThread"):
#1  0x00007fb59f39937e in g_main_context_iterate.constprop () at /usr/lib64/libglib-2.0.so.0
#2  0x00007fb59f39949f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007fb5a0e364fb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007fb5a0de9ac3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb5a0c603d7 in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#7  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#8  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 9 (Thread 0x7fb572ffd640 (LWP 2577) "QSGRenderThread"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a2741ad7 in QSGRenderThread::processEventsAndWaitForMore() () at /usr/lib64/libQt5Quick.so.5
#3  0x00007fb5a2743f89 in QSGRenderThread::run() () at /usr/lib64/libQt5Quick.so.5
#4  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#6  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 8 (Thread 0x7fb588811640 (LWP 2557) "QQuickPixmapRea"):
#1  0x00007fb59f399345 in g_main_context_iterate.constprop () at /usr/lib64/libglib-2.0.so.0
#2  0x00007fb59f39949f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007fb5a0e364fb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#4  0x00007fb5a0de9ac3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#5  0x00007fb5a0c603d7 in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#6  0x00007fb5a2697226 in QQuickPixmapReader::run() () at /usr/lib64/libQt5Quick.so.5
#7  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#8  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#9  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 7 (Thread 0x7fb589afe640 (LWP 2437) "QQmlThread"):
#1  0x00007fb59f397245 in g_source_iter_next () at /usr/lib64/libglib-2.0.so.0
#2  0x00007fb59f3987a3 in g_main_context_prepare () at /usr/lib64/libglib-2.0.so.0
#3  0x00007fb59f3992a6 in g_main_context_iterate.constprop () at /usr/lib64/libglib-2.0.so.0
#4  0x00007fb59f39949f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#5  0x00007fb5a0e364fb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#6  0x00007fb5a0de9ac3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#7  0x00007fb5a0c603d7 in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#8  0x00007fb5a22e9ff5 in QQmlThreadPrivate::run() () at /usr/lib64/libQt5Qml.so.5
#9  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#10 0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#11 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 6 (Thread 0x7fb598dd5640 (LWP 2349) "plasmas:disk$3"):
#1  0x00007fb59abd60cb in util_queue_thread_func () at /usr/lib64/dri/i965_dri.so
#2  0x00007fb59abd5b97 in impl_thrd_routine () at /usr/lib64/dri/i965_dri.so
#3  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#4  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 5 (Thread 0x7fb5995d6640 (LWP 2348) "plasmas:disk$2"):
#1  0x00007fb59abd60cb in util_queue_thread_func () at /usr/lib64/dri/i965_dri.so
#2  0x00007fb59abd5b97 in impl_thrd_routine () at /usr/lib64/dri/i965_dri.so
#3  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#4  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 4 (Thread 0x7fb599dd7640 (LWP 2347) "plasmas:disk$1"):
#1  0x00007fb59abd60cb in util_queue_thread_func () at /usr/lib64/dri/i965_dri.so
#2  0x00007fb59abd5b97 in impl_thrd_routine () at /usr/lib64/dri/i965_dri.so
#3  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#4  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7fb59a5d8640 (LWP 2346) "plasmas:disk$0"):
#1  0x00007fb59abd60cb in util_queue_thread_func () at /usr/lib64/dri/i965_dri.so
#2  0x00007fb59abd5b97 in impl_thrd_routine () at /usr/lib64/dri/i965_dri.so
#3  0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#4  0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7fb59bcbd640 (LWP 2305) "QDBusConnection"):
#1  0x00007fb59f3e55ff in g_wakeup_acknowledge () at /usr/lib64/libglib-2.0.so.0
#2  0x00007fb59f398e86 in g_main_context_check () at /usr/lib64/libglib-2.0.so.0
#3  0x00007fb59f399326 in g_main_context_iterate.constprop () at /usr/lib64/libglib-2.0.so.0
#4  0x00007fb59f39949f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#5  0x00007fb5a0e364fb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#6  0x00007fb5a0de9ac3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#7  0x00007fb5a0c603d7 in QThread::exec() () at /usr/lib64/libQt5Core.so.5
#8  0x00007fb5a10c69d7 in QDBusConnectionManager::run() () at /usr/lib64/libQt5DBus.so.5
#9  0x00007fb5a0c615bc in QThreadPrivate::start(void*) () at /usr/lib64/libQt5Core.so.5
#10 0x00007fb59fd12f9e in start_thread () at /lib64/libpthread.so.0
#11 0x00007fb5a08f964f in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7fb59c817d00 (LWP 2275) "plasmashell"):
#1  0x00007fb5a0c66e5b in QWaitCondition::wait(QMutex*, QDeadlineTimer) () at /usr/lib64/libQt5Core.so.5
#2  0x00007fb5a2745751 in QSGThreadedRenderLoop::polishAndSync(QSGThreadedRenderLoop::Window*, bool) () at /usr/lib64/libQt5Quick.so.5
#3  0x00007fb5a27468fb in QSGThreadedRenderLoop::handleExposure(QQuickWindow*) () at /usr/lib64/libQt5Quick.so.5
#4  0x00007fb5a12c3115 in QWindow::event(QEvent*) () at /usr/lib64/libQt5Gui.so.5
#5  0x00007fb5a199e6af in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib64/libQt5Widgets.so.5
#6  0x00007fb5a0deb098 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib64/libQt5Core.so.5
#7  0x00007fb5a12b9501 in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) () at /usr/lib64/libQt5Gui.so.5
#8  0x00007fb5a129a32b in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Gui.so.5
#9  0x00007fb59f034cb0 in userEventSourceDispatch(_GSource*, int (*)(void*), void*) () at /usr/lib64/libQt5WaylandClient.so.5
#10 0x00007fb59f39913b in g_main_context_dispatch () at /usr/lib64/libglib-2.0.so.0
#11 0x00007fb59f3993e8 in g_main_context_iterate.constprop () at /usr/lib64/libglib-2.0.so.0
#12 0x00007fb59f39949f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#13 0x00007fb5a0e364db in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#14 0x00007fb5a0de9ac3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib64/libQt5Core.so.5
#15 0x00007fb5a0df1530 in QCoreApplication::exec() () at /usr/lib64/libQt5Core.so.5
#16 0x000055958b40a413 in main ()
[Inferior 1 (process 2275) detached]






Issue 2: Connecting the external FHD screen messes up the 4K screen layout.
Please see attached screenshot where the background picture is no longer scaled correctly up until the user performs a right-click on the desktop.
Comment 3 Leonard Lausen 2021-03-07 21:46:03 UTC 
Created attachment 136474 [details]
desktop background issue when system tray on FHD screen
Comment 4 Leonard Lausen 2021-03-07 21:48:33 UTC 
Created attachment 136475 [details]
desktop background issue when system tray on FHD screen resolved after right click

Note the filesize of this .png screenshot was double the size of screenshot taken before "right click"
Comment 5 Leonard Lausen 2021-03-07 21:50:19 UTC 
Created attachment 136476 [details]
system-tray and layout issue when system tray on 4K screen
Comment 6 Nate Graham 2021-03-12 15:40:26 UTC 
Yes, please do file new bug reports for those. Thanks!