Distribution: Debian Unstable
Kernel: 4.16.0-1-amd64 #1 SMP Debian 4.16.5-1
KDE Plasma version: 5.12.5
KDE Frameworks: 5.46.0
Qt version: 5.10.1

Steps to reproduce
1. Launch a Plasma Wayland session or a nested kwin_wayland on X11.
2. Set the window decoration to Arc or Plastik or any Aurorae theme.
3. Open any application (for example, Dolphin).
4. Close the application.
5. KWin always crashes and brings down the whole desktop, if using a full Wayland session.

Backtrace:
Thread 1 "kwin_wayland" received signal SIGABRT, Aborted.
__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
51	../sysdeps/unix/sysv/linux/raise.c: No existe el fichero o el directorio.

Thread 18 (Thread 0x7f949efe6700 (LWP 5895)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139ac3cc70)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139ac3cc20, cond=0x56139ac3cc48)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139ac3cc48, mutex=0x56139ac3cc20) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f949efe6700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 16 (Thread 0x7f95363bc700 (LWP 5871)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7f958a942fb8)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x7f958a942f68, cond=0x7f958a942f90)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x7f958a942f90, mutex=0x7f958a942f68) at pthread_cond_wait.c:655
#3  0x00007f958a64c6a4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#4  0x00007f958a64c6e9 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#5  0x00007f958cc405aa in start_thread (arg=0x7f95363bc700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 15 (Thread 0x7f9536bbd700 (LWP 5870)):
#0  0x00007f958cc4681a in futex_reltimed_wait_cancelable (private=<optimized out>, reltime=0x7f9536bbcb00, expected=0, futex_word=0x56139a899710) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  0x00007f958cc4681a in __pthread_cond_wait_common (abstime=0x7f9536bbcbc0, mutex=0x56139a8996c0, cond=0x56139a8996e8)
    at pthread_cond_wait.c:533
#2  0x00007f958cc4681a in __pthread_cond_timedwait (cond=cond@entry=0x56139a8996e8, mutex=mutex@entry=0x56139a8996c0, abstime=abstime@entry=0x7f9536bbcbc0) at pthread_cond_wait.c:667
#3  0x00007f958b8b8e78 in QWaitConditionPrivate::wait_relative(unsigned long) (time=30000, this=0x56139a8996c0)
    at thread/qwaitcondition_unix.cpp:133
#4  0x00007f958b8b8e78 in QWaitConditionPrivate::wait(unsigned long) (time=30000, this=0x56139a8996c0)
    at thread/qwaitcondition_unix.cpp:141
#5  0x00007f958b8b8e78 in QWaitCondition::wait(QMutex*, unsigned long) (this=this@entry=0x56139a8ecf50, mutex=mutex@entry=0x56139a7e6cd0, time=30000) at thread/qwaitcondition_unix.cpp:215
#6  0x00007f958b8b4ebd in QThreadPoolThread::run() (this=0x56139a8ecf40) at thread/qthreadpool.cpp:146
#7  0x00007f958b8b7b4f in QThreadPrivate::start(void*) (arg=0x56139a8ecf40) at thread/qthread_unix.cpp:376
#8  0x00007f958cc405aa in start_thread (arg=0x7f9536bbd700) at pthread_create.c:463
#9  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 13 (Thread 0x7f95377fe700 (LWP 5868)):
#0  0x00007f958af915d9 in __GI___poll (fds=0x7f9528003ce0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f9581f1a439 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f9581f1a54c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f958baf919f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f9528000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f958ba9cb6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f95377fdc40, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#5  0x00007f958b8b27ea in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:522
#6  0x00007f9586066885 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007f958b8b7b4f in QThreadPrivate::start(void*) (arg=0x56139a8a55b0) at thread/qthread_unix.cpp:376
#8  0x00007f958cc405aa in start_thread (arg=0x7f95377fe700) at pthread_create.c:463
#9  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 12 (Thread 0x7f9537fff700 (LWP 5867)):
#0  0x00007f958cc4681a in futex_reltimed_wait_cancelable (private=<optimized out>, reltime=0x7f9537ffeb00, expected=0, futex_word=0x56139a7e6fb0) at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  0x00007f958cc4681a in __pthread_cond_wait_common (abstime=0x7f9537ffebc0, mutex=0x56139a7e6f60, cond=0x56139a7e6f88)
    at pthread_cond_wait.c:533
#2  0x00007f958cc4681a in __pthread_cond_timedwait (cond=cond@entry=0x56139a7e6f88, mutex=mutex@entry=0x56139a7e6f60, abstime=abstime@entry=0x7f9537ffebc0) at pthread_cond_wait.c:667
#3  0x00007f958b8b8e78 in QWaitConditionPrivate::wait_relative(unsigned long) (time=30000, this=0x56139a7e6f60)
    at thread/qwaitcondition_unix.cpp:133
#4  0x00007f958b8b8e78 in QWaitConditionPrivate::wait(unsigned long) (time=30000, this=0x56139a7e6f60)
    at thread/qwaitcondition_unix.cpp:141
#5  0x00007f958b8b8e78 in QWaitCondition::wait(QMutex*, unsigned long) (this=this@entry=0x56139a7e6da0, mutex=mutex@entry=0x56139a7e6cd0, time=30000) at thread/qwaitcondition_unix.cpp:215
#6  0x00007f958b8b4ebd in QThreadPoolThread::run() (this=0x56139a7e6d90) at thread/qthreadpool.cpp:146
#7  0x00007f958b8b7b4f in QThreadPrivate::start(void*) (arg=0x56139a7e6d90) at thread/qthread_unix.cpp:376
#8  0x00007f958cc405aa in start_thread (arg=0x7f9537fff700) at pthread_create.c:463
#9  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 11 (Thread 0x7f9554ff9700 (LWP 5866)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a7a5e70)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a7a5e20, cond=0x56139a7a5e48)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a7a5e48, mutex=0x56139a7a5e20) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f9554ff9700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 10 (Thread 0x7f95557fa700 (LWP 5865)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a6dd93c)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a6dd8e8, cond=0x56139a6dd910)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a6dd910, mutex=0x56139a6dd8e8) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f95557fa700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 0x7f9555ffb700 (LWP 5864)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a6dd93c)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a6dd8e8, cond=0x56139a6dd910)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a6dd910, mutex=0x56139a6dd8e8) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f9555ffb700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7f95567fc700 (LWP 5863)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a6dd828)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a6dd7d8, cond=0x56139a6dd800)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a6dd800, mutex=0x56139a6dd7d8) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f95567fc700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7f9556ffd700 (LWP 5862)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a6dd828)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a6dd7d8, cond=0x56139a6dd800)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a6dd800, mutex=0x56139a6dd7d8) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f9556ffd700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7f95577fe700 (LWP 5861)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a6dd82c)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a6dd7d8, cond=0x56139a6dd800)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a6dd800, mutex=0x56139a6dd7d8) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f95577fe700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7f9557fff700 (LWP 5860)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a6498b8)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a649868, cond=0x56139a649890)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a649890, mutex=0x56139a649868) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f9557fff700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7f95651f0700 (LWP 5859)):
#0  0x00007f958cc464ec in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x56139a6da6f0)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f958cc464ec in __pthread_cond_wait_common (abstime=0x0, mutex=0x56139a6da6a0, cond=0x56139a6da6c8)
    at pthread_cond_wait.c:502
#2  0x00007f958cc464ec in __pthread_cond_wait (cond=0x56139a6da6c8, mutex=0x56139a6da6a0) at pthread_cond_wait.c:655
#3  0x00007f9566602edb in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#4  0x00007f9566602c07 in  () at /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so
#5  0x00007f958cc405aa in start_thread (arg=0x7f95651f0700) at pthread_create.c:463
#6  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7f956da1a700 (LWP 5855)):
#0  0x00007f958af915d9 in __GI___poll (fds=0x7f9560003ce0, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f9581f1a439 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f9581f1a54c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f958baf919f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f9560000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f958ba9cb6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f956da19c60, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#5  0x00007f958b8b27ea in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:522
#6  0x00007f958b8b7b4f in QThreadPrivate::start(void*) (arg=0x56139a333fb0) at thread/qthread_unix.cpp:376
#7  0x00007f958cc405aa in start_thread (arg=0x7f956da1a700) at pthread_create.c:463
#8  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f956e21b700 (LWP 5854)):
#0  0x00007f958af915d9 in __GI___poll (fds=0x7f9568005440, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f9581f1a439 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f9581f1a54c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f958baf919f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f9568000b20, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007f958ba9cb6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f956e21ac30, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#5  0x00007f958b8b27ea in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:522
#6  0x00007f958d157df5 in  () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007f958b8b7b4f in QThreadPrivate::start(void*) (arg=0x7f958d3cad60) at thread/qthread_unix.cpp:376
#8  0x00007f958cc405aa in start_thread (arg=0x7f956e21b700) at pthread_create.c:463
#9  0x00007f958af9bcbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f958e2f0940 (LWP 5849)):
#0  0x00007f958aed9e7b in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#1  0x00007f958aedb231 in __GI_abort () at abort.c:79
#2  0x00007f958aed29da in __assert_fail_base (fmt=0x7f958e24d14e "%s%s%s:%u: %s%sLa declaración `%s' no se cumple.\n%n", assertion=assertion@entry=0x7f958dede272 "m_windows.contains(c)", file=file@entry=0x7f958dede2e0 "/build/kwin-posrbs/kwin-5.12.5/scene.cpp", line=line@entry=414, function=function@entry=0x7f958dede480 <KWin::Scene::windowClosed(KWin::Toplevel*, KWin::Deleted*)::__PRETTY_FUNCTION__> "void KWin::Scene::windowClosed(KWin::Toplevel*, KWin::Deleted*)")
    at assert.c:92
#3  0x00007f958aed2a52 in __GI___assert_fail (assertion=assertion@entry=0x7f958dede272 "m_windows.contains(c)", file=file@entry=0x7f958dede2e0 "/build/kwin-posrbs/kwin-5.12.5/scene.cpp", line=line@entry=414, function=function@entry=0x7f958dede480 <KWin::Scene::windowClosed(KWin::Toplevel*, KWin::Deleted*)::__PRETTY_FUNCTION__> "void KWin::Scene::windowClosed(KWin::Toplevel*, KWin::Deleted*)") at assert.c:101
#4  0x00007f958ddea81f in KWin::Scene::windowClosed(KWin::Toplevel*, KWin::Deleted*) (this=0x56139a674530, c=<optimized out>, deleted=0x56139ae43f70) at ./scene.cpp:414
#5  0x00007f958debbc43 in KWin::Scene::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>)
    at ./obj-x86_64-linux-gnu/kwin_autogen/EWIEGA46WW/moc_scene.cpp:98
#6  0x00007f958bace195 in QMetaObject::activate(QObject*, int, int, void**) (sender=sender@entry=0x56139a90bf70, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=5, argv=argv@entry=0x7ffc61200f80)
    at kernel/qobject.cpp:3767
#7  0x00007f958bace867 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x56139a90bf70, m=m@entry=0x7f958e16dc80 <KWin::Toplevel::staticMetaObject>, local_signal_index=local_signal_index@entry=5, argv=argv@entry=0x7ffc61200f80) at kernel/qobject.cpp:3629
#8  0x00007f958deb48de in KWin::Toplevel::windowClosed(KWin::Toplevel*, KWin::Deleted*) (this=this@entry=0x56139a90bf70, _t1=<optimized out>, _t1@entry=0x56139a90bf70, _t2=<optimized out>, _t2@entry=0x56139ae43f70)
    at ./obj-x86_64-linux-gnu/kwin_autogen/EWIEGA46WW/moc_toplevel.cpp:718
#9  0x00007f958de599ac in KWin::ShellClient::destroyClient() (this=0x56139a90bf70) at ./shell_client.cpp:362
#10 0x00007f958bace2af in QtPrivate::QSlotObjectBase::call(QObject*, void**) (a=0x7ffc612010f0, r=0x56139a90bf70, this=0x56139a32e9a0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:378
#11 0x00007f958bace2af in QMetaObject::activate(QObject*, int, int, void**) (sender=sender@entry=0x56139a3303b0, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffc612010f0)
    at kernel/qobject.cpp:3750
#12 0x00007f958bace867 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x56139a3303b0, m=m@entry=0x7f958bef7a60 <QObject::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffc612010f0) at kernel/qobject.cpp:3629
#13 0x00007f958bace90f in QObject::destroyed(QObject*) (this=this@entry=0x56139a3303b0, _t1=<optimized out>, 
    _t1@entry=0x56139a3303b0) at .moc/moc_qobject.cpp:214
#14 0x00007f958bad50ca in QObject::~QObject() (this=<optimized out>, __in_chrg=<optimized out>)
    at kernel/qobject.cpp:902
#15 0x00007f958cef8327 in KWayland::Server::XdgTopLevelV6Interface::~XdgTopLevelV6Interface() (this=0x56139a3303b0, __in_chrg=<optimized out>) at ./src/server/xdgshell_v6_interface_p.h:92
#16 0x00007f958cef8327 in KWayland::Server::XdgTopLevelV6Interface::~XdgTopLevelV6Interface() (this=0x56139a3303b0, __in_chrg=<optimized out>) at ./src/server/xdgshell_v6_interface_p.h:92
#17 0x00007f958baced20 in QObject::event(QEvent*) (this=0x56139a3303b0, e=<optimized out>) at kernel/qobject.cpp:1238
#18 0x00007f958c0616cc in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=
    0x56139a309e80, receiver=receiver@entry=0x56139a3303b0, e=e@entry=0x56139acc5c40) at kernel/qapplication.cpp:3732
#19 0x00007f958c068e84 in QApplication::notify(QObject*, QEvent*) (this=0x7ffc61202460, receiver=0x56139a3303b0, e=0x56139acc5c40) at kernel/qapplication.cpp:3491
#20 0x00007f958ba9e938 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x56139a3303b0, event=event@entry=0x56139acc5c40) at kernel/qcoreapplication.cpp:1050
#21 0x00007f958baa14cd in QCoreApplication::sendEvent(QObject*, QEvent*) (event=0x56139acc5c40, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#22 0x00007f958baa14cd in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=0x0, event_type=52, data=0x56139a312330) at kernel/qcoreapplication.cpp:1740
#23 0x00007f958687930d in QQuickRenderControlPrivate::windowDestroyed() (this=this@entry=0x56139abdbbc0)
    at items/qquickrendercontrol.cpp:190
#24 0x00007f9586879640 in QQuickRenderControlPrivate::windowDestroyed() (this=0x56139abdbbc0)
    at items/qquickrendercontrol.cpp:176
#25 0x00007f9586879640 in QQuickRenderControl::~QQuickRenderControl() (this=0x56139abf6ed0, __in_chrg=<optimized out>)
    at items/qquickrendercontrol.cpp:181
#26 0x00007f9586879669 in QQuickRenderControl::~QQuickRenderControl() (this=0x56139abf6ed0, __in_chrg=<optimized out>)
    at items/qquickrendercontrol.cpp:184
#27 0x00007f955c2698ce in Aurorae::Decoration::~Decoration() (this=0x56139aa1c250, __in_chrg=<optimized out>)
    at ./plugins/kdecorations/aurorae/src/aurorae.cpp:273
#28 0x00007f955c269a09 in Aurorae::Decoration::~Decoration() (this=0x56139aa1c250, __in_chrg=<optimized out>)
    at ./plugins/kdecorations/aurorae/src/aurorae.cpp:280
#29 0x00007f958dd2b176 in KWin::AbstractClient::destroyDecoration() (this=0x56139a90bf70) at ./abstract_client.cpp:1435
#30 0x00007f958de599c0 in KWin::ShellClient::destroyClient() (this=0x56139a90bf70) at ./shell_client.cpp:364
#31 0x00007f958bace2af in QtPrivate::QSlotObjectBase::call(QObject*, void**) (a=0x7ffc61201650, r=0x56139a90bf70, this=0x56139a853360) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:378
#32 0x00007f958bace2af in QMetaObject::activate(QObject*, int, int, void**) (sender=0x56139a330850, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3750
#33 0x00007f958bace867 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=<optimized out>, m=m@entry=0x7f958d13cec0 <KWayland::Server::Resource::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3629
#34 0x00007f958cefd390 in KWayland::Server::Resource::unbound() (this=<optimized out>)
    at ./obj-x86_64-linux-gnu/src/server/KF5WaylandServer_autogen/EWIEGA46WW/moc_resource.cpp:138
#35 0x00007f958ced7448 in KWayland::Server::Resource::Private::unbind(wl_resource*) (r=<optimized out>)
    at ./src/server/resource.cpp:68
#36 0x00007f9583e65f82 in destroy_resource (element=element@entry=0x56139a3314b0, data=data@entry=0x0, flags=0)
    at ../src/wayland-server.c:688
#37 0x00007f9583e65fde in wl_resource_destroy (resource=0x56139a3314b0) at ../src/wayland-server.c:705
#38 0x00007f957d1ecfce in ffi_call_unix64 () at /usr/lib/x86_64-linux-gnu/libffi.so.6
#39 0x00007f957d1ec93f in ffi_call () at /usr/lib/x86_64-linux-gnu/libffi.so.6
#40 0x00007f9583e69d04 in wl_closure_invoke (closure=closure@entry=0x56139adf87b0, flags=flags@entry=2, target=<optimized out>, target@entry=0x56139a3314b0, opcode=opcode@entry=0, data=<optimized out>, data@entry=0x56139a330a70)
    at ../src/connection.c:996
#41 0x00007f9583e6633f in wl_client_connection_data (fd=<optimized out>, mask=<optimized out>, data=0x56139a330a70)
    at ../src/wayland-server.c:420
#42 0x00007f9583e67d72 in wl_event_loop_dispatch (loop=0x56139a4bdbc0, timeout=timeout@entry=0)
    at ../src/event-loop.c:641
#43 0x00007f958cebbc7e in KWayland::Server::Display::Private::dispatch() (this=<optimized out>)
    at ./src/server/display.cpp:140
#44 0x00007f958bace2af in QtPrivate::QSlotObjectBase::call(QObject*, void**) (a=0x7ffc61201de0, r=0x56139a5d4130, this=0x56139a5d4500) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:378
#45 0x00007f958bace2af in QMetaObject::activate(QObject*, int, int, void**) (sender=sender@entry=0x56139a5d44e0, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffc61201de0)
    at kernel/qobject.cpp:3750
#46 0x00007f958bace867 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) (sender=sender@entry=0x56139a5d44e0, m=m@entry=0x7f958beffd80 <QSocketNotifier::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffc61201de0) at kernel/qobject.cpp:3629
#47 0x00007f958bada6f8 in QSocketNotifier::activated(int, QSocketNotifier::QPrivateSignal) (this=this@entry=0x56139a5d44e0, _t1=<optimized out>, _t2=...) at .moc/moc_qsocketnotifier.cpp:136
#48 0x00007f958badaac2 in QSocketNotifier::event(QEvent*) (this=0x56139a5d44e0, e=0x7ffc61202050)
    at kernel/qsocketnotifier.cpp:266
#49 0x00007f958c0616cc in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x56139a309e80, receiver=receiver@entry=0x56139a5d44e0, e=e@entry=0x7ffc61202050) at kernel/qapplication.cpp:3732
#50 0x00007f958c068e84 in QApplication::notify(QObject*, QEvent*) (this=0x7ffc61202460, receiver=0x56139a5d44e0, e=0x7ffc61202050) at kernel/qapplication.cpp:3491
#51 0x00007f958ba9e938 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=receiver@entry=0x56139a5d44e0, event=event@entry=0x7ffc61202050) at kernel/qcoreapplication.cpp:1050
#52 0x00007f958baf6268 in QCoreApplication::sendEvent(QObject*, QEvent*) (event=0x7ffc61202050, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#53 0x00007f958baf6268 in QEventDispatcherUNIXPrivate::activateSocketNotifiers() (this=this@entry=0x56139a3664e0)
    at kernel/qeventdispatcher_unix.cpp:304
#54 0x00007f958baf68e8 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:509
#55 0x00007f95749cda9d in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
    at /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/KWinQpaPlugin.so
#56 0x00007f958ba9cb6a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffc61202200, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#57 0x00007f958baa5ed4 in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1338
#58 0x000056139a041d5a in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at ./main_wayland.cpp:830

Additional information:
KWin does not crash under X11 or if I set the window decoration to Breeze under Wayland. From what I can understand from the backtrace, it seems to me that the window is being destroyed twice, causing the assertion to fail the second time.