Application: systemsettings5 (5.2.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-15-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
It seems to me that yesterday, after upgrade from Kubuntu 14.10, there wasn't this problem, even when i've changed the rendering backend from OpenLG 2.0 to OpenGL 3.1. Now, every time i click on "Display Monitor", in Hardware section, and go back, System Settings crashes.

The crash can be reproduced every time.

-- Backtrace:
Application: Impostazioni di sistema (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f6fd02f0780 (LWP 17937))]

Thread 3 (Thread 0x7f6fbd9a7700 (LWP 17938)):
#0  0x00007f6fcca138dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f6fcad09b72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f6fcad0b64f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f6fc07b3099 in QXcbEventReader::run (this=0x88bc50) at qxcbconnection.cpp:1105
#4  0x00007f6fcd09bb0e in QThreadPrivate::start (arg=0x88bc50) at thread/qthread_unix.cpp:337
#5  0x00007f6fc9c076aa in start_thread (arg=0x7f6fbd9a7700) at pthread_create.c:333
#6  0x00007f6fcca1eeed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f6f9b317700 (LWP 17948)):
#0  0x00007f6fc97267a2 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f6fc96e13f0 in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f6fc96e1de8 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f6fc96e1fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f6fcd332c6c in QEventDispatcherGlib::processEvents (this=0x7f6f940008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#5  0x00007f6fcd2d73e2 in QEventLoop::exec (this=this@entry=0x7f6f9b316e40, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f6fcd096b44 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f6fcd09bb0e in QThreadPrivate::start (arg=0x13eefc0) at thread/qthread_unix.cpp:337
#8  0x00007f6fc9c076aa in start_thread (arg=0x7f6f9b317700) at pthread_create.c:333
#9  0x00007f6fcca1eeed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f6fd02f0780 (LWP 17937)):
[KCrash Handler]
#6  0x00007f6fcbb1cde0 in QQuickWindow::maybeUpdate() () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007f6fcbb08e28 in QQuickItemPrivate::dirty(QQuickItemPrivate::DirtyType) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007f6fcbb13045 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007f6fcd30b73a in QObject::event (this=0x1082890, e=<optimized out>) at kernel/qobject.cpp:1245
#10 0x00007f6fcbb11b6b in QQuickItem::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#11 0x00007f6fce0d3b2c in QApplicationPrivate::notify_helper (this=0x860550, receiver=0x1082890, e=0x7f6f9c187070) at kernel/qapplication.cpp:3720
#12 0x00007f6fce0d9000 in QApplication::notify (this=0x7ffe6c7145c0, receiver=0x1082890, e=0x7f6f9c187070) at kernel/qapplication.cpp:3503
#13 0x00007f6fcd2d9c2b in QCoreApplication::notifyInternal (this=0x7ffe6c7145c0, receiver=0x1082890, event=event@entry=0x7f6f9c187070) at kernel/qcoreapplication.cpp:935
#14 0x00007f6fcd2dbc9b in sendEvent (event=0x7f6f9c187070, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#15 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x85f770) at kernel/qcoreapplication.cpp:1552
#16 0x00007f6fcd2dc298 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1410
#17 0x00007f6fcd332843 in postEventSourceDispatch (s=0x8cb350) at kernel/qeventdispatcher_glib.cpp:271
#18 0x00007f6fc96e1c3d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f6fc96e1f20 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f6fc96e1fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007f6fcd332c57 in QEventDispatcherGlib::processEvents (this=0x8c94a0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#22 0x00007f6fcd2d73e2 in QEventLoop::exec (this=this@entry=0x7ffe6c7144a0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#23 0x00007f6fcd2df02c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#24 0x00007f6fcdb0b31c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#25 0x00007f6fce0cf7a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#26 0x000000000040eebc in main (argc=1, argv=<optimized out>) at ../../app/main.cpp:54

Reported using DrKonqi