plasmashell has started crashing after latest dnf update on Fedora 23. I'm using the focus follows mouse focus policy. The crashes seem to happen when the focus is moved between windows due to movement of the mouse. The crashes don't happen all of the time though. 

Reproducible: Sometimes

Steps to Reproduce:
The crashes happen randomly but seem to be related to the focus moving between windows.



Here is the stack trace from running coredumpctl gdb

#0  0x00007f1974907a98 in __GI_raise (sig=sig@entry=11) at ../sysdeps/unix/sysv/linux/raise.c:55
#1  0x00007f197ccdcedc in KCrash::defaultCrashHandler(int) (sig=11) at /usr/src/debug/kcrash-5.19.0/src/kcrash.cpp:431
#2  0x00007f1974907b20 in <signal handler called> () at /lib64/libc.so.6
#3  0x00000000000000a0 in  ()
#4  0x00007f19757e2ab7 in QMetaObject::activate(QObject*, int, void**) (sender=sender@entry=0x5620ff099290, signal_index=6, argv=argv@entry=0x0) at kernel/qobject.cpp:3759
#5  0x00007f19796e60e2 in VDMModelDelegateDataType::notify(QQmlAdaptorModel const&, QList<QQmlDelegateModelItem*> const&, int, int, QVector<int> const&) const (this=<optimized out>, items=..., index=0, count=1, roles=...) at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/util/qqmladaptormodel.cpp:171
#6  0x00007f197995c1ea in QQmlDelegateModel::_q_itemsChanged(int, int, QVector<int> const&) (roles=..., count=1, index=<optimized out>, items=..., this=0x5620fe3edb48)
    at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/util/qqmladaptormodel_p.h:118
#7  0x00007f197995c1ea in QQmlDelegateModel::_q_itemsChanged(int, int, QVector<int> const&) (this=<optimized out>, index=0, count=1, roles=...)
    at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/types/qqmldelegatemodel.cpp:1144
#8  0x00007f197995c34a in QQmlDelegateModel::_q_dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) (this=<optimized out>, begin=..., end=..., roles=...)
    at /usr/src/debug/qtdeclarative-opensource-src-5.5.1/src/qml/types/qqmldelegatemodel.cpp:1546
#9  0x00007f197998386c in QQmlDelegateModel::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=_o@entry=0x5620fe240c40, _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=12, _a=_a@entry=0x7fff34894d40) at .moc/moc_qqmldelegatemodel_p.cpp:203
#10 0x00007f1979984058 in QQmlDelegateModel::qt_metacall(QMetaObject::Call, int, void**) (this=0x5620fe240c40, _c=QMetaObject::InvokeMetaMethod, _id=12, _a=0x7fff34894d40)
    at .moc/moc_qqmldelegatemodel_p.cpp:344
#11 0x00007f19757e2450 in QMetaObject::activate(QObject*, int, int, void**) (sender=0x5620fe3d7e90, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff34894d40) at kernel/qobject.cpp:3728
#12 0x00007f19757e2a97 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=<optimized out>, m=m@entry=0x7f1975bf9600 <QAbstractItemModel::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff34894d40) at kernel/qobject.cpp:3578
#13 0x00007f197585eaac in QAbstractItemModel::dataChanged(QModelIndex const&, QModelIndex const&, QVector<int> const&) (this=<optimized out>, _t1=..., _t2=..., _t3=...) at .moc/moc_qabstractitemmodel.cpp:548
#14 0x00007f18b2b8928f in TaskManager::TasksModel::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (changes=..., this=0x5620fe3e63d0)
    at /usr/src/debug/plasma-workspace-5.5.4/libtaskmanager/tasksmodel.cpp:521
#15 0x00007f18b2b8928f in TaskManager::TasksModel::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=_o@entry=0x5620fe3d7e90, _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=9, _a=_a@entry=0x7fff34894ef0) at /usr/src/debug/plasma-workspace-5.5.4/x86_64-redhat-linux-gnu/libtaskmanager/moc_tasksmodel.cpp:214
#16 0x00007f19757e229a in QMetaObject::activate(QObject*, int, int, void**) (sender=0x5620fecd7900, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff34894ef0) at kernel/qobject.cpp:3713
#17 0x00007f19757e2a97 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=<optimized out>, m=m@entry=0x7f18b2daff60 <TaskManager::AbstractGroupableItem::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff34894ef0) at kernel/qobject.cpp:3578
#18 0x00007f18b2b928e8 in TaskManager::AbstractGroupableItem::changed(QFlags<TaskManager::TaskChange>) (this=<optimized out>, _t1=...)
    at /usr/src/debug/plasma-workspace-5.5.4/x86_64-redhat-linux-gnu/libtaskmanager/moc_abstractgroupableitem.cpp:223
#19 0x00007f18b2b7b5b8 in TaskManager::TaskItem::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (change=..., this=<optimized out>)
    at /usr/src/debug/plasma-workspace-5.5.4/libtaskmanager/taskitem.cpp:73
#20 0x00007f18b2b7b5b8 in TaskManager::TaskItem::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=_o@entry=0x5620fecd7900, _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=16, _a=_a@entry=0x7fff34895040) at /usr/src/debug/plasma-workspace-5.5.4/x86_64-redhat-linux-gnu/libtaskmanager/moc_taskitem.cpp:147
#21 0x00007f19757e229a in QMetaObject::activate(QObject*, int, int, void**) (sender=sender@entry=0x5620fe01c830, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff34895040) at kernel/qobject.cpp:3713
#22 0x00007f19757e2a97 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x5620fe01c830, m=m@entry=0x7f18b2dafc60 <TaskManager::Task::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fff34895040) at kernel/qobject.cpp:3578
#23 0x00007f18b2b92ad8 in TaskManager::Task::changed(QFlags<TaskManager::TaskChange>) (this=this@entry=0x5620fe01c830, _t1=...)
    at /usr/src/debug/plasma-workspace-5.5.4/x86_64-redhat-linux-gnu/libtaskmanager/moc_task.cpp:359
#24 0x00007f18b2b6361b in TaskManager::Task::setActive(bool) (this=this@entry=0x5620fe01c830, a=a@entry=true) at /usr/src/debug/plasma-workspace-5.5.4/libtaskmanager/task.cpp:178
#25 0x00007f18b2b822d9 in TaskManager::TaskManager::activeWindowChanged(unsigned long long) (this=0x7f18b2db2060 <TaskManager::(anonymous namespace)::Q_QGS_privateTaskManagerSelf::innerFunction()::holder>, w=<optimized out>) at /usr/src/debug/plasma-workspace-5.5.4/libtaskmanager/taskmanager.cpp:412
#26 0x00007f19757e2127 in QMetaObject::activate(QObject*, int, int, void**) (a=0x7fff348951d0, r=0x7f18b2db2060 <TaskManager::(anonymous namespace)::Q_QGS_privateTaskManagerSelf::innerFunction()::holder>, this=<optimized out>) at ../../src/corelib/kernel/qobject_impl.h:124
#27 0x00007f19757e2127 in QMetaObject::activate(QObject*, int, int, void**) (sender=sender@entry=0x7f19792bc3a0 <(anonymous namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=3, argv=argv@entry=0x7fff348951d0) at kernel/qobject.cpp:3698
#28 0x00007f19757e2a97 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x7f19792bc3a0 <(anonymous namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>, m=m@entry=0x7f19792baca0 <KWindowSystem::staticMetaObject>, local_signal_index=local_signal_index@entry=3, argv=argv@entry=0x7fff348951d0) at kernel/qobject.cpp:3578
#29 0x00007f19790ad042 in KWindowSystem::activeWindowChanged(unsigned long long) (this=this@entry=0x7f19792bc3a0 <(anonymous namespace)::Q_QGS_g_kwmInstanceContainer::innerFunction()::holder>, _t1=171966688)
    at /usr/src/debug/kwindowsystem-5.19.0/x86_64-redhat-linux-gnu/src/moc_kwindowsystem.cpp:303
#30 0x00007f195685930b in NETEventFilter::nativeEventFilter(xcb_generic_event_t*) (this=0x5620fe2f7250, ev=<optimized out>) at /usr/src/debug/kwindowsystem-5.19.0/src/platforms/xcb/kwindowsystem.cpp:250
#31 0x00007f19757b005f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) (this=<optimized out>, eventType=..., message=message@entry=0x7f1958006fa0, result=result@entry=0x7fff34895308) at kernel/qabstracteventdispatcher.cpp:460
#32 0x00007f195f032534 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) (this=this@entry=0x5620fcd920d0, event=event@entry=0x7f1958006fa0) at qxcbconnection.cpp:1035
#33 0x00007f195f033433 in QXcbConnection::processXcbEvents() (this=0x5620fcd920d0) at qxcbconnection.cpp:1528
#34 0x00007f19757e3161 in QObject::event(QEvent*) (this=0x5620fcd920d0, e=<optimized out>) at kernel/qobject.cpp:1239
#35 0x00007f1976d6741c in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x5620fcd87460, receiver=receiver@entry=0x5620fcd920d0, e=e@entry=0x7f19580035a0)
    at kernel/qapplication.cpp:3716
#36 0x00007f1976d6c8e6 in QApplication::notify(QObject*, QEvent*) (this=0x7fff34895a90, receiver=0x5620fcd920d0, e=0x7f19580035a0) at kernel/qapplication.cpp:3499
#37 0x00007f19757b373b in QCoreApplication::notifyInternal(QObject*, QEvent*) (this=0x7fff34895a90, receiver=0x5620fcd920d0, event=event@entry=0x7f19580035a0) at kernel/qcoreapplication.cpp:965
#38 0x00007f19757b5b36 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (event=0x7f19580035a0, receiver=<optimized out>) at kernel/qcoreapplication.h:224
#39 0x00007f19757b5b36 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x5620fcd7d550)
    at kernel/qcoreapplication.cpp:1593
#40 0x00007f19757b6018 in QCoreApplication::sendPostedEvents(QObject*, int) (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1451
#41 0x00007f1975809aa3 in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0x5620fcddf9f0) at kernel/qeventdispatcher_glib.cpp:271
#42 0x00007f196feeee3a in g_main_context_dispatch (context=0x7f19580016f0) at gmain.c:3154
#43 0x00007f196feeee3a in g_main_context_dispatch (context=context@entry=0x7f19580016f0) at gmain.c:3769
#44 0x00007f196feef1d0 in g_main_context_iterate (context=context@entry=0x7f19580016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3840
#45 0x00007f196feef27c in g_main_context_iteration (context=0x7f19580016f0, may_block=may_block@entry=1) at gmain.c:3901
#46 0x00007f1975809eaf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x5620fcdeab70, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#47 0x00007f19757b0eca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fff34895930, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#48 0x00007f19757b8fac in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1229
#49 0x00005620fba5a08a in main(int, char**) (argc=3, argv=<optimized out>) at /usr/src/debug/plasma-workspace-5.5.4/shell/main.cpp:181