Bug 451776

SUMMARY
Reproducible: Always
kwin will always crash as soon as you drag a folder from firefox' bookmark sidebar or the Library window over plasmashell  (desktop background) or dolphin (possibly other windows, not Konsole though)
Note that dolphin only crashes when dragging over the "folder view" part in the middle of the window that shows all files of the current dir.

STEPS TO REPRODUCE
1. Create a bookmark folder with more than 1 bookmark
2. Drag that folder over plasma desktop or dolphin
2.1 Instant crash, no dropping (release mouse button 1) required

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.24.3
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.3
Kernel Version: 5.16.15-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor
Memory: 31.3 GiB of RAM
Graphics Processor: AMD Radeon RX 6600 XT

AND

Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.24.80
KDE Frameworks Version: 5.93.0
Qt Version: 5.15.3
Kernel Version: 5.13.0-37-generic (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD EPYC-Milan Processor
Memory: 19.5 GiB of RAM
Graphics Processor: virgl

ADDITIONAL INFORMATION
Backtrace captured in KDE neon vm with (hopefully) most relevant dbgsyms installed:

[New LWP 5676]
[New LWP 5682]
[New LWP 5683]
[New LWP 5685]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007febe93e2ac6 in __ppoll (fds=fds@entry=0x55873d3bd378, nfds=nfds@entry=8, timeout=<optimized out>, timeout@entry=0x7ffc6231fb70, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:44

Thread 1 "kwin_wayland" received signal SIGABRT, Aborted.
__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
50	../sysdeps/unix/sysv/linux/raise.c: No such file or directory.

Thread 5 (Thread 0x7febd5638700 (LWP 5685)):
#0  0x00007febe93e29cf in __GI___poll (fds=0x7febc0005240, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007febe7a4c36e in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007febe7a4c4a3 in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007febea719642 in QEventDispatcherGlib::processEvents (this=0x7febc0000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007febea6bd87b in QEventLoop::exec (this=this@entry=0x7febd5637bc0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007febea4d7442 in QThread::exec (this=this@entry=0x55873ca02c90) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007febeb5d0b39 in QQmlThreadPrivate::run (this=0x55873ca02c90) at qml/ftw/qqmlthread.cpp:155
#7  0x00007febea4d8623 in QThreadPrivate::start (arg=0x55873ca02c90) at thread/qthread_unix.cpp:331
#8  0x00007febea2bc609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#9  0x00007febe93ef163 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7febe0ec2700 (LWP 5683)):
#0  0x00007febe93e29cf in __GI___poll (fds=0x7febc8005240, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007febe7a4c36e in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007febe7a4c4a3 in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007febea719642 in QEventDispatcherGlib::processEvents (this=0x7febc8000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007febea6bd87b in QEventLoop::exec (this=this@entry=0x7febe0ec1be0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007febea4d7442 in QThread::exec (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007febea4d8623 in QThreadPrivate::start (arg=0x55873c8032f0) at thread/qthread_unix.cpp:331
#7  0x00007febea2bc609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#8  0x00007febe93ef163 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7febe1771700 (LWP 5682)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55873c7f18c8) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55873c7f1878, cond=0x55873c7f18a0) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x55873c7f18a0, mutex=0x55873c7f1878) at pthread_cond_wait.c:638
#3  0x00007febe1bd45eb in ?? () from /usr/lib/x86_64-linux-gnu/dri/virtio_gpu_dri.so
#4  0x00007febe1bd41eb in ?? () from /usr/lib/x86_64-linux-gnu/dri/virtio_gpu_dri.so
#5  0x00007febea2bc609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007febe93ef163 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7febe3e65700 (LWP 5676)):
#0  0x00007febe93e29cf in __GI___poll (fds=0x7febdc0053c0, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007febe7a4c36e in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007febe7a4c4a3 in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007febea719642 in QEventDispatcherGlib::processEvents (this=0x7febdc000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#4  0x00007febea6bd87b in QEventLoop::exec (this=this@entry=0x7febe3e64bb0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#5  0x00007febea4d7442 in QThread::exec (this=this@entry=0x7febec384d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#6  0x00007febec300f4b in QDBusConnectionManager::run (this=0x7febec384d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:179
#7  0x00007febea4d8623 in QThreadPrivate::start (arg=0x7febec384d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:331
#8  0x00007febea2bc609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#9  0x00007febe93ef163 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7febe4bd89c0 (LWP 5668)):
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1  0x00007febe92f2859 in __GI_abort () at abort.c:79
#2  0x00007febe96b1911 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#3  0x00007febe96bd38c in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4  0x00007febe96bd3f7 in std::terminate() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5  0x00007febe96bd6a9 in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#6  0x00007febea49bf7b in qBadAlloc () at /usr/include/c++/9/bits/exception.h:63
#7  0x00007febea49ff3a in QByteArray::reallocData (this=0x7ffc6231f598, alloc=2147483640, options=...) at text/qbytearray.cpp:1847
#8  0x00007febea5302dd in QByteArray::append (this=this@entry=0x7ffc6231f598, str=0x55873d607ac8 " visualsfm-mardy on Ubuntu using the Snap Store | Snapcraft\nhttps://snapcraft.io/store\nInstall Linux apps using the Snap Store | Snapcraft", len=len@entry=59) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#9  0x000055873b8773e5 in KWin::Xwl::MozUrlReceiver::setData (this=0x55873d568f40, value=<optimized out>, length=410) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qarraydata.h:208
#10 0x000055873b878232 in KWin::Xwl::TransferXtoWl::startTransfer (this=this@entry=0x55873da04180) at ./src/xwl/transfer.cpp:376
#11 0x000055873b8785be in KWin::Xwl::TransferXtoWl::handleSelectionNotify (this=0x55873da04180, event=event@entry=0x55873d568f70) at ./src/xwl/transfer.cpp:347
#12 0x000055873b8730e4 in KWin::Xwl::Selection::handleSelectionNotify (this=<optimized out>, event=0x55873d568f70) at ./src/xwl/selection.cpp:257
#13 0x000055873b86a41c in KWin::Xwl::DataBridge::nativeEventFilter (this=0x55873d342930, eventType=..., message=0x55873d568f70) at ./src/xwl/databridge.cpp:68
#14 0x00007febea6bc20f in QAbstractEventDispatcher::filterNativeEvent (this=<optimized out>, eventType=..., message=message@entry=0x55873d568f70, result=result@entry=0x7ffc6231f758) at kernel/qabstracteventdispatcher.cpp:495
#15 0x000055873b87b828 in KWin::Xwl::Xwayland::dispatchEvents (this=0x55873cada240) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qbytearray.h:463
#16 0x00007febea6f5dfe in QtPrivate::QSlotObjectBase::call (a=0x7ffc6231f8b0, r=0x55873cada240, this=0x55873d33fda0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#17 doActivate<false> (sender=0x55873d311920, signal_index=3, argv=0x7ffc6231f8b0) at kernel/qobject.cpp:3886
#18 0x00007febea6ef1c7 in QMetaObject::activate (sender=sender@entry=0x55873d311920, m=m@entry=0x7febea95ab40 <QSocketNotifier::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffc6231f8b0) at kernel/qobject.cpp:3946
#19 0x00007febea6f9e83 in QSocketNotifier::activated (this=this@entry=0x55873d311920, _t1=..., _t2=<optimized out>, _t3=...) at .moc/moc_qsocketnotifier.cpp:178
#20 0x00007febea6fa623 in QSocketNotifier::event (this=0x55873d311920, e=0x7ffc6231fb80) at kernel/qsocketnotifier.cpp:302
#21 0x00007febe9a45dc3 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#22 0x00007febe9a4ebd8 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#23 0x00007febea6bed7a in QCoreApplication::notifyInternal2 (receiver=0x55873d311920, event=0x7ffc6231fb80) at ../../include/QtCore/5.15.3/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:332
#24 0x00007febea71686b in QEventDispatcherUNIXPrivate::activateSocketNotifiers (this=0x55873c752100) at kernel/qeventdispatcher_unix.cpp:304
#25 0x00007febea716ccb in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:511
#26 0x000055873b981ae1 in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
#27 0x00007febea6bd87b in QEventLoop::exec (this=this@entry=0x7ffc6231fd10, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#28 0x00007febea6c5a24 in QCoreApplication::exec () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#29 0x000055873b860e6e in main (argc=<optimized out>, argv=<optimized out>) at ./src/main_wayland.cpp:680
A debugging session is active.

	Inferior 1 [process 5668] will be detached.