SUMMARY
This backtrace was generated on Neon unstable edition,
but I can reproduce the same crash on Arch Linux.


STEPS TO REPRODUCE
1. start Wayland sesison
2. open any app, let's say Dolphin, via kickoff
3. open kickoff
4. right click on an entry of your favorites list
5. while the context menu is open, left click on the same entry that you right-clicked
6. right click on Dolphin's entry in the task manager

OBSERVED RESULT
plasma crashes

EXPECTED RESULT
no crash

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.16.80
KDE Frameworks Version: 5.60.0
Qt Version: 5.12.3

Operating System: Arch Linux 
KDE Plasma Version: 5.16.3
KDE Frameworks Version: 5.60.0
Qt Version: 5.13.0


Thread 10 (Thread 0x7fe2d96f3700 (LWP 2012)):
#0  0x00007fe33e67abf9 in __GI___poll (fds=0x561f6b95c0c0, nfds=2, timeout=-1)
    at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fe3389025c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe3389026dc in g_main_context_iteration ()
   from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe338902721 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fe33892a195 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fe33bcbd6db in start_thread (arg=0x7fe2d96f3700) at pthread_create.c:463
#6  0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 0x7fe330597700 (LWP 1977)):
#0  0x00007fe33e67abf9 in __GI___poll (fds=0x7fe328003ce0, nfds=3, timeout=-1)
    at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fe3389025c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe3389026dc in g_main_context_iteration ()
   from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe33efbddaf in QEventDispatcherGlib::processEvents (this=0x7fe328000b20, 
    flags=...) at kernel/qeventdispatcher_glib.cpp:422
#4  0x00007fe33ef5f03a in QEventLoop::exec (this=this@entry=0x7fe330596d70, 
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007fe33ed864ca in QThread::exec (
    this=this@entry=0x7fe3402e0d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread.cpp:531
#6  0x00007fe340069015 in QDBusConnectionManager::run (
    this=0x7fe3402e0d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#7  0x00007fe33ed87c72 in QThreadPrivate::start (
    arg=0x7fe3402e0d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:361
#8  0x00007fe33bcbd6db in start_thread (arg=0x7fe330597700) at pthread_create.c:463
#9  0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7fe2ed7d1700 (LWP 2003)):
#0  0x00007fe33bcc39f3 in futex_wait_cancelable (private=<optimized out>, 
    expected=0, futex_word=0x561f69dd6f94)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x561f69dd6f40, 
    cond=0x561f69dd6f68) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x561f69dd6f68, mutex=0x561f69dd6f40)
    at pthread_cond_wait.c:655
#3  0x00007fe33ed8edbb in QWaitConditionPrivate::wait (deadline=..., 
    this=0x561f69dd6f40) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x561f69c7b640, deadline=...)
    at thread/qwaitcondition_unix.cpp:225
#5  0x00007fe33ed8f0c9 in QWaitCondition::wait (this=this@entry=0x561f69c7b648, 
    mutex=mutex@entry=0x561f69c7b640, time=time@entry=18446744073709551615)
    at thread/qwaitcondition_unix.cpp:208
#6  0x00007fe3430e06f8 in QSGRenderThreadEventQueue::takeEvent (wait=true, 
    this=0x561f69c7b638) at scenegraph/qsgthreadedrenderloop.cpp:245
#7  QSGRenderThread::processEventsAndWaitForMore (this=this@entry=0x561f69c7b5c0)
    at scenegraph/qsgthreadedrenderloop.cpp:710
#8  0x00007fe3430e0b2a in QSGRenderThread::run (this=0x561f69c7b5c0)
    at scenegraph/qsgthreadedrenderloop.cpp:739
#9  0x00007fe33ed87c72 in QThreadPrivate::start (arg=0x561f69c7b5c0)
    at thread/qthread_unix.cpp:361
#10 0x00007fe33bcbd6db in start_thread (arg=0x7fe2ed7d1700) at pthread_create.c:463
#11 0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7fe2d8ef2700 (LWP 2049)):
#0  0x00007fe33bcc39f3 in futex_wait_cancelable (private=<optimized out>, 
    expected=0, futex_word=0x561f677889e4)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x561f67788990, 
    cond=0x561f677889b8) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x561f677889b8, mutex=0x561f67788990)
    at pthread_cond_wait.c:655
#3  0x00007fe33ed8edbb in QWaitConditionPrivate::wait (deadline=..., 
    this=0x561f67788990) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x561f6b756fc0, deadline=...)
    at thread/qwaitcondition_unix.cpp:225
#5  0x00007fe33ed8f0c9 in QWaitCondition::wait (this=this@entry=0x561f6b756fc8, 
    mutex=mutex@entry=0x561f6b756fc0, time=time@entry=18446744073709551615)
    at thread/qwaitcondition_unix.cpp:208
#6  0x00007fe3430e06f8 in QSGRenderThreadEventQueue::takeEvent (wait=true, 
    this=0x561f6b756fb8) at scenegraph/qsgthreadedrenderloop.cpp:245
#7  QSGRenderThread::processEventsAndWaitForMore (this=this@entry=0x561f6b756f40)
    at scenegraph/qsgthreadedrenderloop.cpp:710
#8  0x00007fe3430e0b2a in QSGRenderThread::run (this=0x561f6b756f40)
    at scenegraph/qsgthreadedrenderloop.cpp:739
#9  0x00007fe33ed87c72 in QThreadPrivate::start (arg=0x561f6b756f40)
    at thread/qthread_unix.cpp:361
#10 0x00007fe33bcbd6db in start_thread (arg=0x7fe2d8ef2700) at pthread_create.c:463
#11 0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7fe32eb5f700 (LWP 1978)):
#0  0x00007fe33e67abf9 in __GI___poll (fds=0x7fe320004e00, nfds=1, timeout=-1)
    at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fe3389025c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe3389026dc in g_main_context_iteration ()
   from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe33efbddaf in QEventDispatcherGlib::processEvents (this=0x7fe320000b20, 
    flags=...) at kernel/qeventdispatcher_glib.cpp:422
#4  0x00007fe33ef5f03a in QEventLoop::exec (this=this@entry=0x7fe32eb5ed80, 
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007fe33ed864ca in QThread::exec (this=this@entry=0x561f66252bf0)
    at thread/qthread.cpp:531
#6  0x00007fe342b95115 in QQmlThreadPrivate::run (this=0x561f66252bf0)
    at qml/ftw/qqmlthread.cpp:148
#7  0x00007fe33ed87c72 in QThreadPrivate::start (arg=0x561f66252bf0)
    at thread/qthread_unix.cpp:361
#8  0x00007fe33bcbd6db in start_thread (arg=0x7fe32eb5f700) at pthread_create.c:463
#9  0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7fe2ece50700 (LWP 2011)):
#0  0x00007fe33e67abf9 in __GI___poll (fds=0x7fe2d0003ce0, nfds=1, timeout=9993)
    at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fe3389025c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe3389026dc in g_main_context_iteration ()
   from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe33efbddaf in QEventDispatcherGlib::processEvents (this=0x7fe2d0000b20, 
    flags=...) at kernel/qeventdispatcher_glib.cpp:422
#4  0x00007fe33ef5f03a in QEventLoop::exec (this=this@entry=0x7fe2ece4fda0, 
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#5  0x00007fe33ed864ca in QThread::exec (this=<optimized out>)
    at thread/qthread.cpp:531
#6  0x00007fe33ed87c72 in QThreadPrivate::start (arg=0x561f6943a560)
    at thread/qthread_unix.cpp:361
#7  0x00007fe33bcbd6db in start_thread (arg=0x7fe2ece50700) at pthread_create.c:463
#8  0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7fe31ffff700 (LWP 1981)):
#0  0x00007fe33bcc39f3 in futex_wait_cancelable (private=<optimized out>, 
    expected=0, futex_word=0x561f6618c678)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x561f6618c628, 
    cond=0x561f6618c650) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x561f6618c650, mutex=0x561f6618c628)
    at pthread_cond_wait.c:655
#3  0x00007fe3255e53da in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007fe3255e5107 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007fe33bcbd6db in start_thread (arg=0x7fe31ffff700) at pthread_create.c:463
#6  0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7fe2ef3ca700 (LWP 1994)):
#0  0x00007fe33bcc39f3 in futex_wait_cancelable (private=<optimized out>, 
    expected=0, futex_word=0x561f679cf2a4)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x561f679cf250, 
    cond=0x561f679cf278) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x561f679cf278, mutex=0x561f679cf250)
    at pthread_cond_wait.c:655
#3  0x00007fe33ed8edbb in QWaitConditionPrivate::wait (deadline=..., 
    this=0x561f679cf250) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x561f66de5930, deadline=...)
    at thread/qwaitcondition_unix.cpp:225
#5  0x00007fe33ed8f0c9 in QWaitCondition::wait (this=this@entry=0x561f66de5938, 
    mutex=mutex@entry=0x561f66de5930, time=time@entry=18446744073709551615)
    at thread/qwaitcondition_unix.cpp:208
#6  0x00007fe3430e06f8 in QSGRenderThreadEventQueue::takeEvent (wait=true, 
    this=0x561f66de5928) at scenegraph/qsgthreadedrenderloop.cpp:245
#7  QSGRenderThread::processEventsAndWaitForMore (this=this@entry=0x561f66de58b0)
    at scenegraph/qsgthreadedrenderloop.cpp:710
#8  0x00007fe3430e0b2a in QSGRenderThread::run (this=0x561f66de58b0)
    at scenegraph/qsgthreadedrenderloop.cpp:739
#9  0x00007fe33ed87c72 in QThreadPrivate::start (arg=0x561f66de58b0)
    at thread/qthread_unix.cpp:361
#10 0x00007fe33bcbd6db in start_thread (arg=0x7fe2ef3ca700) at pthread_create.c:463
#11 0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7fe310d4c700 (LWP 1987)):
#0  0x00007fe33bcc39f3 in futex_wait_cancelable (private=<optimized out>, 
    expected=0, futex_word=0x561f668e1ad0)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x561f668e1a80, 
    cond=0x561f668e1aa8) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x561f668e1aa8, mutex=0x561f668e1a80)
    at pthread_cond_wait.c:655
#3  0x00007fe33ed8edbb in QWaitConditionPrivate::wait (deadline=..., 
    this=0x561f668e1a80) at thread/qwaitcondition_unix.cpp:146
#4  QWaitCondition::wait (this=<optimized out>, mutex=0x561f668dc900, deadline=...)
    at thread/qwaitcondition_unix.cpp:225
#5  0x00007fe33ed8f0c9 in QWaitCondition::wait (this=this@entry=0x561f668dc908, 
    mutex=mutex@entry=0x561f668dc900, time=time@entry=18446744073709551615)
    at thread/qwaitcondition_unix.cpp:208
#6  0x00007fe3430e06f8 in QSGRenderThreadEventQueue::takeEvent (wait=true, 
    this=0x561f668dc8f8) at scenegraph/qsgthreadedrenderloop.cpp:245
#7  QSGRenderThread::processEventsAndWaitForMore (this=this@entry=0x561f668dc880)
    at scenegraph/qsgthreadedrenderloop.cpp:710
#8  0x00007fe3430e0b2a in QSGRenderThread::run (this=0x561f668dc880)
    at scenegraph/qsgthreadedrenderloop.cpp:739
#9  0x00007fe33ed87c72 in QThreadPrivate::start (arg=0x561f668dc880)
    at thread/qthread_unix.cpp:361
#10 0x00007fe33bcbd6db in start_thread (arg=0x7fe310d4c700) at pthread_create.c:463
#11 0x00007fe33e68788f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7fe345289800 (LWP 1975)):
#0  __GI_raise (sig=sig@entry=7) at ../sysdeps/unix/sysv/linux/raise.c:51
#1  0x00007fe341cbcc03 in KCrash::defaultCrashHandler (sig=7) at ./src/kcrash.cpp:439
#2  <signal handler called>
#3  0x00007fe3121060d8 in QtWaylandClient::QWaylandXdgSurface::setGrabPopup (
    this=0x561f6c079ef0, parent=0x561f66d2f3e0, device=0x561f6616b5a0, serial=1278)
    at qwaylandxdgshell.cpp:371
#4  0x00007fe3121068fa in QtWaylandClient::QWaylandXdgShell::getXdgSurface (
    this=0x561f66b037c0, window=0x561f6e32aa00) at qwaylandxdgshell.cpp:420
#5  0x00007fe3328879c4 in QtWaylandClient::QWaylandWindow::initWindow (
    this=this@entry=0x561f6e32aa00) at qwaylandwindow.cpp:142
#6  0x00007fe332887ff4 in QtWaylandClient::QWaylandWindow::setVisible (
    this=this@entry=0x561f6e32aa00, visible=<optimized out>)
    at qwaylandwindow.cpp:389
#7  0x00007fe327df99b4 in QtWaylandClient::QWaylandEglWindow::setVisible (
    this=0x561f6e32aa00, visible=<optimized out>)
    at ../../../../hardwareintegration/client/wayland-egl/qwaylandeglwindow.cpp:168
#8  0x00007fe33f535234 in QWindowPrivate::setVisible (this=0x561f6ed64c60, 
    visible=visible@entry=true) at kernel/qwindow.cpp:402
#9  0x00007fe340919dbd in QWidgetWindow::setNativeWindowVisibility (
    this=this@entry=0x561f6bdfe6a0, visible=visible@entry=true)
    at kernel/qwidgetwindow.cpp:205
#10 0x00007fe3408f4366 in QWidgetPrivate::show_sys (this=this@entry=0x561f6e473ed0)
    at kernel/qwidget.cpp:8156
#11 0x00007fe3408fd3cb in QWidgetPrivate::show_helper (
    this=this@entry=0x561f6e473ed0) at kernel/qwidget.cpp:8079
#12 0x00007fe340900523 in QWidgetPrivate::setVisible (this=0x561f6e473ed0, 
    visible=<optimized out>) at kernel/qwidget.cpp:8381
#13 0x00007fe340a35720 in QMenu::popup (this=0x561f6baa8c50, p=..., 
    atAction=atAction@entry=0x0) at widgets/qmenu.cpp:2580
#14 0x00007fe31ed7a337 in QMenuProxy::openInternal (this=this@entry=0x561f6bbab670, 
    pos=...) at ./src/declarativeimports/plasmacomponents/qmenu.cpp:460
#15 0x00007fe31ed7b143 in QMenuProxy::openRelative (this=0x561f6bbab670)
    at ./src/declarativeimports/plasmacomponents/qmenu.cpp:430
#16 0x00007fe31ed7eb45 in QMenuProxy::qt_static_metacall (_o=_o@entry=
    0x561f6bbab670, _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=12, 
    _a=_a@entry=0x7ffcedf2b360)
    at ./obj-x86_64-linux-gnu/src/declarativeimports/plasmacomponents/plasmacomponentsplugin_autogen/EWIEGA46WW/moc_qmenu.cpp:197
#17 0x00007fe31ed7f135 in QMenuProxy::qt_metacall (this=0x561f6bbab670, 
    _c=QMetaObject::InvokeMetaMethod, _id=12, _a=0x7ffcedf2b360)
    at ./obj-x86_64-linux-gnu/src/declarativeimports/plasmacomponents/plasmacomponentsplugin_autogen/EWIEGA46WW/moc_qmenu.cpp:380
#18 0x00007fe342ae2f3e in QQmlVMEMetaObject::metaCall (this=0x561f6be79da0, 
    o=<optimized out>, c=QMetaObject::InvokeMetaMethod, _id=17, a=0x7ffcedf2b360)
    at qml/qqmlvmemetaobject.cpp:981
#19 0x00007fe342b37b09 in QQmlObjectOrGadget::metacall (
    this=this@entry=0x7ffcedf2b650, type=type@entry=QMetaObject::InvokeMetaMethod, 
    index=<optimized out>, index@entry=17, argv=argv@entry=0x7ffcedf2b360)
    at qml/qqmlpropertycache.cpp:1770
#20 0x00007fe342a3ec8b in CallMethod (object=..., index=17, 
    returnType=returnType@entry=43, argCount=argCount@entry=0, 
    argTypes=argTypes@entry=0x0, engine=engine@entry=0x561f6624de40, 
    callArgs=0x7fe32df20728, callType=QMetaObject::InvokeMetaMethod)
    at jsruntime/qv4qobjectwrapper.cpp:1314
#21 0x00007fe342a40c62 in CallPrecise (object=..., data=..., 
    engine=engine@entry=0x561f6624de40, callArgs=callArgs@entry=0x7fe32df20728, 
    callType=callType@entry=QMetaObject::InvokeMetaMethod)
    at jsruntime/qv4qobjectwrapper.cpp:1562
#22 0x00007fe342a41931 in QV4::QObjectMethod::callInternal (this=<optimized out>, 
    thisObject=0x7fe32df20720, argv=<optimized out>, argc=<optimized out>)
    at jsruntime/qv4qobjectwrapper.cpp:2119
#23 0x00007fe342ac34fa in QV4::FunctionObject::call (argc=0, argv=0x7fe32df20688, 
    thisObject=0x7fe32df20720, this=0x7ffcedf2b7b8)
    at jsruntime/qv4functionobject_p.h:202
#24 QV4::Runtime::method_callQmlContextPropertyLookup (engine=0x561f6624de40, 
    index=<optimized out>, argv=0x7fe32df20688, argc=0)
    at jsruntime/qv4runtime.cpp:1337
#25 0x00007fe342a5a4b8 in QV4::Moth::VME::interpret (frame=0x7ffcedf2b9b0, 
    engine=0x561f6624de40, 
    code=0x7fe30197b45c <error: Não é possível acessar a memória no endereço 0x7fe30197b45c>) at jsruntime/qv4vme_moth.cpp:762
#26 0x00007fe342a5f406 in QV4::Moth::VME::exec (frame=frame@entry=0x7ffcedf2b9b0, 
    engine=engine@entry=0x561f6624de40) at jsruntime/qv4vme_moth.cpp:441
#27 0x00007fe3429ef0e8 in QV4::ArrowFunction::virtualCall (fo=<optimized out>, 
    thisObject=<optimized out>, argv=<optimized out>, argc=<optimized out>)
    at jsruntime/qv4functionobject.cpp:520
#28 0x00007fe342a5c153 in QV4::FunctionObject::call (argc=<optimized out>, 
    argv=<optimized out>, thisObject=<optimized out>, this=<optimized out>)
    at ../../include/QtQml/5.12.3/QtQml/private/../../../../../src/qml/jsruntime/qv4functionobject_p.h:202
#29 QV4::Moth::VME::interpret (frame=0x7ffcedf2bbf0, engine=0x561f6624de40, 
    code=0x7fe301bc342f <error: Não é possível acessar a memória no endereço 0x7fe301bc342f>) at jsruntime/qv4vme_moth.cpp:732
#30 0x00007fe342a5f406 in QV4::Moth::VME::exec (frame=frame@entry=0x7ffcedf2bbf0, 
    engine=engine@entry=0x561f6624de40) at jsruntime/qv4vme_moth.cpp:441
#31 0x00007fe3429ef0e8 in QV4::ArrowFunction::virtualCall (fo=<optimized out>, 
    thisObject=<optimized out>, argv=<optimized out>, argc=<optimized out>)
    at jsruntime/qv4functionobject.cpp:520
#32 0x00007fe342ac34fa in QV4::FunctionObject::call (argc=0, argv=0x7fe32df20510, 
    thisObject=0x7fe32df205d0, this=0x7ffcedf2bc98)
    at jsruntime/qv4functionobject_p.h:202
#33 QV4::Runtime::method_callQmlContextPropertyLookup (engine=0x561f6624de40, 
    index=<optimized out>, argv=0x7fe32df20510, argc=0)
    at jsruntime/qv4runtime.cpp:1337
#34 0x00007fe308037a96 in ?? ()
#35 0x0000000000000000 in ?? ()