Application: plasmashell (5.15.2)
 (Compiled from sources)
Qt Version: 5.12.1
Frameworks Version: 5.55.0
Operating System: Linux 4.20.12-arch1-1-ARCH x86_64
Distribution: "Arch Linux"

-- Information about the crash:
- What I was doing when the application crashed:

Select a file from dolphin, drag it down to the virtual desktop selector to switch desktop.

- Unusual behavior I noticed:

Either the wrong desktop is moved to or plasma crashes and restarts.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fb1d0cbf680 (LWP 2593))]

Thread 8 (Thread 0x7fb1a3fff700 (LWP 7669)):
#0  0x00007fb1b537381d in  () at /usr/lib/pulseaudio/libpulsecommon-12.2.so
#1  0x00007fb1b537422e in pa_fdsem_before_poll () at /usr/lib/pulseaudio/libpulsecommon-12.2.so
#2  0x00007fb1b538c558 in  () at /usr/lib/pulseaudio/libpulsecommon-12.2.so
#3  0x00007fb1b57f3d18 in pa_mainloop_dispatch () at /usr/lib/libpulse.so.0
#4  0x00007fb1b57f3fef in pa_mainloop_iterate () at /usr/lib/libpulse.so.0
#5  0x00007fb1b57f4091 in pa_mainloop_run () at /usr/lib/libpulse.so.0
#6  0x00007fb1b58025ae in  () at /usr/lib/libpulse.so.0
#7  0x00007fb1b539c9fc in  () at /usr/lib/pulseaudio/libpulsecommon-12.2.so
#8  0x00007fb1d5112a9d in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007fb1d5cfdb23 in clone () at /usr/lib/libc.so.6

Thread 7 (Thread 0x7fb1a9e35700 (LWP 2623)):
#0  0x00007fb1d4170424 in g_mutex_unlock () at /usr/lib/libglib-2.0.so.0
#1  0x00007fb1d41c1dfd in g_main_context_prepare () at /usr/lib/libglib-2.0.so.0
#2  0x00007fb1d41c2466 in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007fb1d41c262e in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#4  0x00007fb1d6225d04 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fb1d61ceb2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#6  0x00007fb1d6012569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#7  0x00007fb1b481735a in KCupsConnection::run() () at /usr/lib/libkcupslib.so
#8  0x00007fb1d601396c in  () at /usr/lib/libQt5Core.so.5
#9  0x00007fb1d5112a9d in start_thread () at /usr/lib/libpthread.so.0
#10 0x00007fb1d5cfdb23 in clone () at /usr/lib/libc.so.6

Thread 6 (Thread 0x7fb1b7fff700 (LWP 2602)):
#0  0x00007fb1d41703b9 in g_mutex_lock () at /usr/lib/libglib-2.0.so.0
#1  0x00007fb1d41b8f72 in g_main_context_query () at /usr/lib/libglib-2.0.so.0
#2  0x00007fb1d41c24bc in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007fb1d41c262e in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#4  0x00007fb1d6225d04 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fb1d61ceb2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#6  0x00007fb1d6012569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#7  0x00007fb1d7cdee7b in  () at /usr/lib/libQt5Quick.so.5
#8  0x00007fb1d601396c in  () at /usr/lib/libQt5Core.so.5
#9  0x00007fb1d5112a9d in start_thread () at /usr/lib/libpthread.so.0
#10 0x00007fb1d5cfdb23 in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7fb1bf24a700 (LWP 2601)):
#0  0x00007fb1d5118afc in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fb1bf7fec94 in  () at /usr/lib/dri/i965_dri.so
#2  0x00007fb1bf7fe9b8 in  () at /usr/lib/dri/i965_dri.so
#3  0x00007fb1d5112a9d in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007fb1d5cfdb23 in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7fb1cdcd3700 (LWP 2600)):
#0  0x00007fb1d5cf2c21 in poll () at /usr/lib/libc.so.6
#1  0x00007fb1d41c2540 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007fb1d41c262e in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007fb1d6225d04 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fb1d61ceb2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fb1d6012569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#6  0x00007fb1d7a17969 in  () at /usr/lib/libQt5Qml.so.5
#7  0x00007fb1d601396c in  () at /usr/lib/libQt5Core.so.5
#8  0x00007fb1d5112a9d in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007fb1d5cfdb23 in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7fb1cef1e700 (LWP 2599)):
#0  0x00007fb1d5cf2c21 in poll () at /usr/lib/libc.so.6
#1  0x00007fb1d41c2540 in  () at /usr/lib/libglib-2.0.so.0
#2  0x00007fb1d41c262e in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#3  0x00007fb1d6225d04 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fb1d61ceb2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#5  0x00007fb1d6012569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#6  0x00007fb1d6aaeba6 in  () at /usr/lib/libQt5DBus.so.5
#7  0x00007fb1d601396c in  () at /usr/lib/libQt5Core.so.5
#8  0x00007fb1d5112a9d in start_thread () at /usr/lib/libpthread.so.0
#9  0x00007fb1d5cfdb23 in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7fb1cfee4700 (LWP 2598)):
#0  0x00007fb1d5cf2c21 in poll () at /usr/lib/libc.so.6
#1  0x00007fb1d8159630 in  () at /usr/lib/libxcb.so.1
#2  0x00007fb1d815b2db in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007fb1d0872949 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007fb1d601396c in  () at /usr/lib/libQt5Core.so.5
#5  0x00007fb1d5112a9d in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007fb1d5cfdb23 in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7fb1d0cbf680 (LWP 2593)):
[KCrash Handler]
#6  0x00007fb1d620e016 in QVariant::toInt(bool*) const () at /usr/lib/libQt5Core.so.5
#7  0x00007fb1cc7ef808 in  () at /usr/lib/libtaskmanager.so.6
#8  0x00007fb1b5ba04b2 in  () at /usr/lib/qt/qml/org/kde/plasma/private/pager/libpagerplugin.so
#9  0x00007fb1b5ba0b3b in  () at /usr/lib/qt/qml/org/kde/plasma/private/pager/libpagerplugin.so
#10 0x00007fb1b5ba0f03 in  () at /usr/lib/qt/qml/org/kde/plasma/private/pager/libpagerplugin.so
#11 0x00007fb1d79bbe0e in  () at /usr/lib/libQt5Qml.so.5
#12 0x00007fb1d78bed32 in  () at /usr/lib/libQt5Qml.so.5
#13 0x00007fb1d78c03e5 in  () at /usr/lib/libQt5Qml.so.5
#14 0x00007fb1d78c106f in QV4::QObjectMethod::callInternal(QV4::Value const*, QV4::Value const*, int) const () at /usr/lib/libQt5Qml.so.5
#15 0x00007fb1d7947c45 in QV4::Runtime::method_callProperty(QV4::ExecutionEngine*, QV4::Value*, int, QV4::Value*, int) () at /usr/lib/libQt5Qml.so.5
#16 0x00007fb1d78da527 in  () at /usr/lib/libQt5Qml.so.5
#17 0x00007fb1d78df2ff in  () at /usr/lib/libQt5Qml.so.5
#18 0x00007fb1d787097c in QV4::Function::call(QV4::Value const*, QV4::Value const*, int, QV4::ExecutionContext const*) () at /usr/lib/libQt5Qml.so.5
#19 0x00007fb1d79e52c8 in QQmlJavaScriptExpression::evaluate(QV4::CallData*, bool*) () at /usr/lib/libQt5Qml.so.5
#20 0x00007fb1d7987968 in QQmlBoundSignalExpression::evaluate(void**) () at /usr/lib/libQt5Qml.so.5
#21 0x00007fb1d7988b1c in  () at /usr/lib/libQt5Qml.so.5
#22 0x00007fb1d79c6633 in QQmlNotifier::emitNotify(QQmlNotifierEndpoint*, void**) () at /usr/lib/libQt5Qml.so.5
#23 0x00007fb1d7969ce4 in QQmlData::signalEmitted(QAbstractDeclarativeData*, QObject*, int, void**) () at /usr/lib/libQt5Qml.so.5
#24 0x00007fb1d61fa19f in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/libQt5Core.so.5
#25 0x00007fb1d7a6af9b in QQmlTimer::event(QEvent*) () at /usr/lib/libQt5Qml.so.5
#26 0x00007fb1d6d0fe24 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#27 0x00007fb1d6d176e1 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#28 0x00007fb1d61cfe99 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#29 0x00007fb1d61d2f38 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/libQt5Core.so.5
#30 0x00007fb1d6226714 in  () at /usr/lib/libQt5Core.so.5
#31 0x00007fb1d41c0a2f in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#32 0x00007fb1d41c25e9 in  () at /usr/lib/libglib-2.0.so.0
#33 0x00007fb1d41c262e in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#34 0x00007fb1d6225ce9 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#35 0x00007fb1d61ceb2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#36 0x00007fb1d61d6e36 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#37 0x0000564375830d2e in  ()
#38 0x00007fb1d5c26223 in __libc_start_main () at /usr/lib/libc.so.6
#39 0x00005643758311de in _start ()
[Inferior 1 (process 2593) detached]

Reported using DrKonqi