Application: kalarm (2.11.4-5ak)

Qt Version: 5.5.1
Operating System: Linux 4.4.3-1-default x86_64
Distribution: "openSUSE Tumbleweed (20160303) (x86_64)"

-- Information about the crash:
Was waking the laptop from sqleep, connected external monitor. May be the same "no monitor crash" of Qt which has troubled KDE lately (and made me to switch to Gnome after n years of KDE...). 

(OpenSUSE tumbleweed, running gnome, but does have KDE and Qt 5.5.1)

-- Backtrace:
Application: KAlarm (kalarm), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f6b8397a940 (LWP 5198))]

Thread 4 (Thread 0x7f6b621db700 (LWP 5199)):
#0  0x00007f6b7b00649d in poll () at /lib64/libc.so.6
#1  0x00007f6b74f64432 in  () at /usr/lib64/libxcb.so.1
#2  0x00007f6b74f66007 in xcb_wait_for_event () at /usr/lib64/libxcb.so.1
#3  0x00007f6b63f03e29 in QXcbEventReader::run() (this=0xacc790) at qxcbconnection.cpp:1229
#4  0x00007f6b7b90d94f in QThreadPrivate::start(void*) (arg=0xacc790) at thread/qthread_unix.cpp:331
#5  0x00007f6b751814a4 in start_thread () at /lib64/libpthread.so.0
#6  0x00007f6b7b00eded in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7f6b58254700 (LWP 5206)):
#0  0x00007f6b7b00649d in poll () at /lib64/libc.so.6
#1  0x00007f6b74840294 in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007f6b7484039c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007f6b7bb3252b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f6b500008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f6b7badc61a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f6b58253c90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f6b7b908b1c in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007f6b7b90d94f in QThreadPrivate::start(void*) (arg=0xd08c30) at thread/qthread_unix.cpp:331
#7  0x00007f6b751814a4 in start_thread () at /lib64/libpthread.so.0
#8  0x00007f6b7b00eded in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7f6b4f568700 (LWP 5399)):
#0  0x00007f6b74883554 in g_mutex_unlock () at /usr/lib64/libglib-2.0.so.0
#1  0x00007f6b7483f940 in g_main_context_prepare () at /usr/lib64/libglib-2.0.so.0
#2  0x00007f6b748401c3 in  () at /usr/lib64/libglib-2.0.so.0
#3  0x00007f6b7484039c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#4  0x00007f6b7bb3252b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f6b480008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f6b7badc61a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f6b4f567c90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f6b7b908b1c in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f6b7b90d94f in QThreadPrivate::start(void*) (arg=0xb394d0) at thread/qthread_unix.cpp:331
#8  0x00007f6b751814a4 in start_thread () at /lib64/libpthread.so.0
#9  0x00007f6b7b00eded in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7f6b8397a940 (LWP 5198)):
[KCrash Handler]
#6  0x00007f6b7c6114b0 in QScreen::handle() const (this=0x0) at kernel/qscreen.cpp:112
#7  0x00007f6b63f22359 in QXcbBackingStore::resize(QSize const&, QRegion const&) (this=0x10478a0, size=...) at qxcbbackingstore.cpp:440
#8  0x00007f6b7cd98726 in QWidgetBackingStore::doSync() (this=this@entry=0x1047950) at kernel/qwidgetbackingstore.cpp:1063
#9  0x00007f6b7cd99d54 in QWidgetBackingStore::sync() (this=0x1047950) at kernel/qwidgetbackingstore.cpp:1032
#10 0x00007f6b7cdb6e1f in QWidgetPrivate::syncBackingStore() (this=0x10472e0) at kernel/qwidget.cpp:1907
#11 0x00007f6b7cde664d in QWidgetWindow::handleResizeEvent(QResizeEvent*) (this=this@entry=0x10461f0, event=event@entry=0x7fff4bcd84e0) at kernel/qwidgetwindow.cpp:710
#12 0x00007f6b7cde93a3 in QWidgetWindow::event(QEvent*) (this=0x10461f0, event=0x7fff4bcd84e0) at kernel/qwidgetwindow.cpp:232
#13 0x00007f6b7cd8c8cc in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0xab14e0, receiver=receiver@entry=0x10461f0, e=e@entry=0x7fff4bcd84e0) at kernel/qapplication.cpp:3716
#14 0x00007f6b7cd919d6 in QApplication::notify(QObject*, QEvent*) (this=0xaabf80, receiver=0x10461f0, e=0x7fff4bcd84e0) at kernel/qapplication.cpp:3499
#15 0x00007f6b7badecd3 in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0xaabf80, receiver=receiver@entry=0x10461f0, event=event@entry=0x7fff4bcd84e0) at kernel/qcoreapplication.cpp:965
#16 0x00007f6b7c5eaa01 in QGuiApplicationPrivate::processGeometryChangeEvent(QWindowSystemInterfacePrivate::GeometryChangeEvent*) (event=0x7fff4bcd84e0, receiver=0x10461f0) at ../../src/corelib/kernel/qcoreapplication.h:227
#17 0x00007f6b7c5eaa01 in QGuiApplicationPrivate::processGeometryChangeEvent(QWindowSystemInterfacePrivate::GeometryChangeEvent*) (e=<optimized out>) at kernel/qguiapplication.cpp:2069
#18 0x00007f6b7c5ef58d in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) (e=e@entry=0xe5f060) at kernel/qguiapplication.cpp:1595
#19 0x00007f6b7c5d4b38 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) (flags=...) at kernel/qwindowsysteminterface.cpp:625
#20 0x00007f6b63f33ed0 in userEventSourceDispatch(GSource*, GSourceFunc, gpointer) (source=<optimized out>) at eventdispatchers/qeventdispatcher_glib.cpp:70
#21 0x00007f6b748400c7 in g_main_context_dispatch () at /usr/lib64/libglib-2.0.so.0
#22 0x00007f6b748402f8 in  () at /usr/lib64/libglib-2.0.so.0
#23 0x00007f6b7484039c in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#24 0x00007f6b7bb3250f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0xbd4f70, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#25 0x00007f6b7badc61a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fff4bcd8780, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#26 0x00007f6b7bae42dd in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1229
#27 0x00000000004b6719 in main ()

Reported using DrKonqi