Bug 478838

Single screen or multi-screen? Or both?

I can confirm that it happens to me too. Single screen.

Operating System: Arch Linux 
KDE Plasma Version: 5.91.0
KDE Frameworks Version: 5.247.0
Qt Version: 6.7.0
Kernel Version: 6.6.7-1-clear (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-4790 CPU @ 3.60GHz
Memory: 15.6 GiB of RAM
Graphics Processor: AMD Radeon RX 6600

Single screen in my case.

*** Bug 478932 has been marked as a duplicate of this bug. ***

*** Bug 478412 has been marked as a duplicate of this bug. ***

I basically get the exact same backtrace from plasmashell when I disconnect my external HDMI monitor. If it makes any difference the external monitor is connected via a VGA to HDMI adapter to my laptop.

This is on Arch with the kde-unstable repo enabled.
Plasma 6 Beta 2

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.91.0
KDE Frameworks Version: 5.247.0
Qt Version: 6.7.0 (beta)
Kernel Version: 6.7.0-rc6
Graphics Platform: Wayland
Graphics Drivers: mesa 23.3.1-1
Processors: AMD Ryzen 9 4900HS
Memory:  24GB of RAM
Graphics Processor: Integrated: Vega 8
Manufacturer: ASUS (Zephyrus G15 GA502IV)

Created attachment 164435 [details]
plasmashell backtrace

Marking as confirmed from the number of duplicate reports

Looking at the backtrace, does this seem like a issue caused by deleting a QObject in the event loop instead of calling deleteLater()?

I tested this today with Qt 6.6. branch with newest changes. The issue went away for me. I will also test with Qt 6.7.

I still get crashes with this backtrace when I rearrange multiple displays, on both neon unstable, and arch compiled from source with qt6.7. So this shouldn't be a issue of qt 6.7.

For the info I have two panels on each of my displays. The top one is always visible, and the bottom one is dodge windows. Both are non-floating. I am still reproducing when I rearrange displays on latest neon unstable.

*** Bug 482661 has been marked as a duplicate of this bug. ***

Confirmed crash on Arch packaged Plasma Wayland. Two monitors: LG 24UD58-B, which disconnects itself momentarily when it's resumed from DPMS off, whether HDMI or DisplayPort; and a Dell P2414H, which maintains a steady connection regardless of DPMS state, connected by DisplayPort, as it has no HDMI inputs.

Backtrace, resolved with debuginfod as best I could:

```
#0  __pthread_kill_implementation
    (threadid=<optimized out>, signo=signo@entry=11, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007f17380ab393 in __pthread_kill_internal (signo=11, threadid=<optimized out>)
    at pthread_kill.c:78
#2  0x00007f173805a6c8 in __GI_raise (sig=11) at ../sysdeps/posix/raise.c:26
#3  0x00007f173aed943f in KCrash::defaultCrashHandler (sig=11)
    at /usr/src/debug/kcrash/kcrash-6.0.0/src/kcrash.cpp:586
#4  0x00007f173805a770 in <signal handler called> () at /usr/lib/libc.so.6
#5  0x00007f1738db4245 in QPlatformWindow::hasPendingUpdateRequest (this=0x56c294528500)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/gui/kernel/qplatformwindow.cpp:765
#6  0x00007f173abf1acb in operator() (__closure=0x56c295ede0f0)
    at /usr/src/debug/qt6-wayland/qtwayland-everywhere-src-6.7.0/src/client/qwaylandwindow.cpp:1648
#7  QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, QtWaylandClient::QWaylandWindow::requestUpdate()::<lambda()> >::call (arg=<optimized out>, f=...)
    at /usr/include/qt6/QtCore/qobjectdefs_impl.h:137
#8  QtPrivate::FunctorCallable<QtWaylandClient::QWaylandWindow::requestUpdate()::<lambda()> >::call<QtPrivate::List<>, void> (arg=<optimized out>, f=...)
    at /usr/include/qt6/QtCore/qobjectdefs_impl.h:345
#9  QtPrivate::QCallableObject<QtWaylandClient::QWaylandWindow::requestUpdate()::<lambda()>, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void **, bool *)
    (which=<optimized out>, this_=0x56c295ede0e0, r=<optimized out>, a=<optimized out>, ret=<optimized out>) at /usr/include/qt6/QtCore/qobjectdefs_impl.h:555
#10 0x00007f17387883e4 in QObject::event (this=0x56c2945284f0, e=0x56c294020930)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qobject.cpp:1446
#11 0x00007f173a4fbfcb in QApplicationPrivate::notify_helper
    (this=<optimized out>, receiver=0x56c2945284f0, e=0x56c294020930)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/widgets/kernel/qapplication.cpp:3287
#12 0x00007f173873dae8 in QCoreApplication::notifyInternal2
    (receiver=0x56c2945284f0, event=event@entry=0x56c294020930)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qcoreapplication.cpp:1134
#13 0x00007f173873de74 in QCoreApplication::sendEvent
    (event=0x56c294020930, receiver=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qcoreapplication.cpp:1575
#14 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x56c28fd34ba0)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qcoreapplication.cpp:1932
#15 0x00007f17389860e4 in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qcoreapplication.cpp:1789
#16 postEventSourceDispatch (s=0x56c28fd62a90)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qeventdispatcher_glib.cpp:244
#17 0x00007f17372cf199 in g_main_dispatch (context=0x7f172c000f00) at ../glib/glib/gmain.c:3344
#18 0x00007f173732e3bf in g_main_context_dispatch_unlocked (context=0x7f172c000f00)
    at ../glib/glib/gmain.c:4152
#19 g_main_context_iterate_unlocked.isra.0
    (context=context@entry=0x7f172c000f00, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:4217
#20 0x00007f17372ce712 in g_main_context_iteration (context=0x7f172c000f00, may_block=1)
    at ../glib/glib/gmain.c:4282
#21 0x00007f1738983df4 in QEventDispatcherGlib::processEvents (this=0x56c28ffb8620, flags=...)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qeventdispatcher_glib.cpp:394
#22 0x00007f1738745c7e in QEventLoop::processEvents (flags=..., this=0x7fff594a6750)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qeventloop.cpp:100
#23 QEventLoop::exec (this=0x7fff594a6750, flags=...)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/kernel/qeventloop.cpp:182
#24 0x00007f17387416e8 in QCoreApplication::exec ()
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/corelib/global/qflags.h:74
#25 0x00007f173a4f851a in QApplication::exec ()
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.7.0/src/widgets/kernel/qapplication.cpp:2555
#26 0x000056c28e3e7476 in main (argc=<optimized out>, argv=<optimized out>)
    at /usr/src/debug/plasma-workspace/plasma-workspace-6.0.3/shell/main.cpp:214
```