Bug 354851

After moving the systemsettings application window from one monitor to another (I have 2 monitors) and configuring several settings, the app crashes with a segmentation fault.

I've tried this several times and it happens every time I try it. Even if I try to move the systemsettings window back to monitor 1, it still crashes.

I've noticed that sometimes, before systemsettings crashes, the whole desktop freezes for a couple seconds, after which it unfreezes, and the systemsettings app segfaults.

Reproducible: Always

Steps to Reproduce:
1. launch systemsettings
2. move systemsettings to another monitor, also tried moving it back to the first monitor

Actual Results:  
segfault

Expected Results:  
I would expected the application to continue functioning.

Application: System Settings (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f63dc815800 (LWP 1139))]

Thread 4 (Thread 0x7f63c8326700 (LWP 1140)):
#0  0x00007f63d84f618d in poll () from /usr/lib/libc.so.6
#1  0x00007f63d5290ae2 in ?? () from /usr/lib/libxcb.so.1
#2  0x00007f63d5292757 in xcb_wait_for_event () from /usr/lib/libxcb.so.1
#3  0x00007f63ca89ee89 in ?? () from /usr/lib/libQt5XcbQpa.so.5
#4  0x00007f63d8bf796e in ?? () from /usr/lib/libQt5Core.so.5
#5  0x00007f63d4a104a4 in start_thread () from /usr/lib/libpthread.so.0
#6  0x00007f63d84ff13d in clone () from /usr/lib/libc.so.6

Thread 3 (Thread 0x7f63bb459700 (LWP 1142)):
#0  0x00007f63d84f618d in poll () from /usr/lib/libc.so.6
#1  0x00007f63d44f2fbc in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f63d44f30cc in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007f63d44f3109 in ?? () from /usr/lib/libglib-2.0.so.0
#4  0x00007f63d4519715 in ?? () from /usr/lib/libglib-2.0.so.0
#5  0x00007f63d4a104a4 in start_thread () from /usr/lib/libpthread.so.0
#6  0x00007f63d84ff13d in clone () from /usr/lib/libc.so.6

Thread 2 (Thread 0x7f63bac58700 (LWP 1143)):
#0  0x00007f63d84f618d in poll () from /usr/lib/libc.so.6
#1  0x00007f63d44f2fbc in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007f63d44f3342 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#3  0x00007f63bb73e246 in ?? () from /usr/lib/libgio-2.0.so.0
#4  0x00007f63d4519715 in ?? () from /usr/lib/libglib-2.0.so.0
#5  0x00007f63d4a104a4 in start_thread () from /usr/lib/libpthread.so.0
#6  0x00007f63d84ff13d in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7f63dc815800 (LWP 1139)):
[KCrash Handler]
#5  0x00007f63d762a73d in QQuickItemPrivate::addToDirtyList() () from /usr/lib/libQt5Quick.so.5
#6  0x00007f63d762a7d3 in QQuickItemPrivate::dirty(QQuickItemPrivate::DirtyType) () from /usr/lib/libQt5Quick.so.5
#7  0x00007f63d763771d in ?? () from /usr/lib/libQt5Quick.so.5
#8  0x00007f63d8e07ff1 in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#9  0x00007f63d763480b in QQuickItem::event(QEvent*) () from /usr/lib/libQt5Quick.so.5
#10 0x00007f63da97901c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#11 0x00007f63da97e4f6 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#12 0x00007f63d8dd89ab in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#13 0x00007f63d8ddada6 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQt5Core.so.5
#14 0x00007f63d8e2ef43 in ?? () from /usr/lib/libQt5Core.so.5
#15 0x00007f63d44f2dc7 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#16 0x00007f63d44f3020 in ?? () from /usr/lib/libglib-2.0.so.0
#17 0x00007f63d44f30cc in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#18 0x00007f63d8e2f34f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#19 0x00007f63d8dd637a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#20 0x00007f63d8dde33c in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#21 0x000000000040eeab in main ()