Bug 426416

Summary: crash after theme change
Product: [Applications] systemsettings Reporter: ederag <edera>
Component: generalAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: crash CC: kde
Priority: NOR Keywords: drkonqi
Version First Reported In: 5.18.5   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description ederag 2020-09-11 15:58:55 UTC 
Application: systemsettings5 (5.18.5)

Qt Version: 5.12.7
Frameworks Version: 5.71.0
Operating System: Linux 5.3.18-lp152.41-default x86_64
Windowing system: X11
Distribution: "openSUSE Leap 15.2"

-- Information about the crash:
After trying another theme (breeeze dark was OK),
settings crashes when trying to click any icon.

Can't remember the theme name. 
It was one of the first shown, dark, and produces huges buttons.

Right click in any kde window (e.g. konsole or desktop), 
now generates an empty dark rectangle,
instead of a popup.
(as mentioned in bug 426202)

The crash can be reproduced every time.

-- Backtrace:
Application: System Settings (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
29	  return SYSCALL_CANCEL (poll, fds, nfds, timeout);
[Current thread is 1 (Thread 0x7f7a70264900 (LWP 8101))]

Thread 3 (Thread 0x7f7a45c51700 (LWP 8113)):
#0  0x00007f7a6b7361d8 in __GI___libc_read (fd=14, buf=buf@entry=0x7f7a45c50a70, nbytes=nbytes@entry=16) at ../sysdeps/unix/sysv/linux/read.c:26
#1  0x00007f7a64cf99a0 in read (__nbytes=16, __buf=0x7f7a45c50a70, __fd=<optimized out>) at /usr/include/bits/unistd.h:44
#2  g_wakeup_acknowledge (wakeup=0x7f7a480039a0) at ../glib/gwakeup.c:210
#3  0x00007f7a64cb2298 in g_main_context_check (context=context@entry=0x7f7a40000be0, max_priority=2147483647, fds=fds@entry=0x7f7a40004a90, n_fds=n_fds@entry=1) at ../glib/gmain.c:3732
#4  0x00007f7a64cb2720 in g_main_context_iterate (context=context@entry=0x7f7a40000be0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:3951
#5  0x00007f7a64cb288c in g_main_context_iteration (context=0x7f7a40000be0, may_block=may_block@entry=1) at ../glib/gmain.c:4015
#6  0x00007f7a6c0d019b in QEventDispatcherGlib::processEvents (this=0x7f7a40000b10, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#7  0x00007f7a6c07132a in QEventLoop::exec (this=this@entry=0x7f7a45c50c90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#8  0x00007f7a6be9710a in QThread::exec (this=this@entry=0x558691df7440) at thread/qthread.cpp:531
#9  0x00007f7a699e5ba5 in QQmlThreadPrivate::run (this=0x558691df7440) at /usr/src/debug/libqt5-qtdeclarative-5.12.7-lp152.2.2.x86_64/src/qml/qml/ftw/qqmlthread.cpp:148
#10 0x00007f7a6be988b2 in QThreadPrivate::start (arg=0x558691df7440) at thread/qthread_unix.cpp:361
#11 0x00007f7a6740d4f9 in start_thread (arg=0x7f7a45c51700) at pthread_create.c:465
#12 0x00007f7a6b744fbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f7a502cf700 (LWP 8104)):
#0  0x00007f7a6b7361d8 in __GI___libc_read (fd=7, buf=buf@entry=0x7f7a502cea60, nbytes=nbytes@entry=16) at ../sysdeps/unix/sysv/linux/read.c:26
#1  0x00007f7a64cf99a0 in read (__nbytes=16, __buf=0x7f7a502cea60, __fd=<optimized out>) at /usr/include/bits/unistd.h:44
#2  g_wakeup_acknowledge (wakeup=0x5586913845b0) at ../glib/gwakeup.c:210
#3  0x00007f7a64cb2298 in g_main_context_check (context=context@entry=0x7f7a48000be0, max_priority=2147483647, fds=fds@entry=0x7f7a48004e90, n_fds=n_fds@entry=1) at ../glib/gmain.c:3732
#4  0x00007f7a64cb2720 in g_main_context_iterate (context=context@entry=0x7f7a48000be0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:3951
#5  0x00007f7a64cb288c in g_main_context_iteration (context=0x7f7a48000be0, may_block=may_block@entry=1) at ../glib/gmain.c:4015
#6  0x00007f7a6c0d019b in QEventDispatcherGlib::processEvents (this=0x7f7a48000b10, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#7  0x00007f7a6c07132a in QEventLoop::exec (this=this@entry=0x7f7a502cec80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#8  0x00007f7a6be9710a in QThread::exec (this=this@entry=0x7f7a6c7b8d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread.cpp:531
#9  0x00007f7a6c540cd5 in QDBusConnectionManager::run (this=0x7f7a6c7b8d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#10 0x00007f7a6be988b2 in QThreadPrivate::start (arg=0x7f7a6c7b8d80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:361
#11 0x00007f7a6740d4f9 in start_thread (arg=0x7f7a502cf700) at pthread_create.c:465
#12 0x00007f7a6b744fbf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f7a70264900 (LWP 8101)):
[KCrash Handler]
#4  QPixmapStyle::drawControl (this=0x558691380d80, element=QStyle::CE_ShapedFrame, option=0x5586922fefd0, painter=0x7fffb9a746e0, widget=0x0) at styles/qpixmapstyle.cpp:326
#5  0x00007f7a58c526ed in QBB10DarkStyle::drawControl (this=0x558691380d80, element=<optimized out>, option=0x5586922fefd0, painter=0x7fffb9a746e0, widget=0x0) at qbb10darkstyle.cpp:326
#6  0x00007f7a3d9e0794 in KQuickStyleItem::paint (this=this@entry=0x5586922fc830, painter=painter@entry=0x7fffb9a746e0) at /usr/src/debug/qqc2-desktop-style-5.71.0-lp152.1.1.x86_64/plugin/kquickstyleitem.cpp:1501
#7  0x00007f7a3d9e0c1c in KQuickStyleItem::updatePolish (this=0x5586922fc830) at /usr/src/debug/qqc2-desktop-style-5.71.0-lp152.1.1.x86_64/plugin/kquickstyleitem.cpp:1769
#8  0x00007f7a69f94fd3 in QQuickWindowPrivate::polishItems (this=0x558691a9da20) at /usr/src/debug/libqt5-qtdeclarative-5.12.7-lp152.2.2.x86_64/src/quick/items/qquickwindow.cpp:311
#9  0x00007f7a6a057844 in QQuickRenderControl::polishItems (this=<optimized out>) at /usr/src/debug/libqt5-qtdeclarative-5.12.7-lp152.2.2.x86_64/src/quick/items/qquickrendercontrol.cpp:267
#10 0x00007f7a6a85dc15 in QQuickWidgetPrivate::render (this=this@entry=0x558691a9d540, needsSync=<optimized out>) at /usr/src/debug/libqt5-qtdeclarative-5.12.7-lp152.2.2.x86_64/src/quickwidgets/qquickwidget.cpp:296
#11 0x00007f7a6a860a8b in QQuickWidget::resizeEvent (this=0x558691911f50, e=<optimized out>) at /usr/src/debug/libqt5-qtdeclarative-5.12.7-lp152.2.2.x86_64/src/quickwidgets/qquickwidget.cpp:1241
#12 0x00007f7a6d17302e in QWidget::event (this=this@entry=0x558691911f50, event=event@entry=0x7fffb9a74c60) at kernel/qwidget.cpp:9127
#13 0x00007f7a6a861a1b in QQuickWidget::event (this=0x558691911f50, e=0x7fffb9a74c60) at /usr/src/debug/libqt5-qtdeclarative-5.12.7-lp152.2.2.x86_64/src/quickwidgets/qquickwidget.cpp:1537
#14 0x00007f7a6d132a0c in QApplicationPrivate::notify_helper (this=this@entry=0x5586912aa550, receiver=receiver@entry=0x558691911f50, e=e@entry=0x7fffb9a74c60) at kernel/qapplication.cpp:3701
#15 0x00007f7a6d13a020 in QApplication::notify (this=0x7fffb9a76e80, receiver=0x558691911f50, e=0x7fffb9a74c60) at kernel/qapplication.cpp:3447
#16 0x00007f7a6c0730d8 in QCoreApplication::notifyInternal2 (receiver=0x558691911f50, event=0x7fffb9a74c60) at kernel/qcoreapplication.cpp:1088
#17 0x00007f7a6c0732ae in QCoreApplication::sendEvent (receiver=receiver@entry=0x558691911f50, event=event@entry=0x7fffb9a74c60) at kernel/qcoreapplication.cpp:1476
#18 0x00007f7a6d16ba76 in QWidgetPrivate::sendPendingMoveAndResizeEvents (this=this@entry=0x558691a9d540, recursive=recursive@entry=false, disableUpdates=<optimized out>, disableUpdates@entry=false) at kernel/qwidget.cpp:7969
#19 0x00007f7a6d16f6f3 in QWidgetPrivate::show_helper (this=this@entry=0x558691a9d540) at kernel/qwidget.cpp:8020
#20 0x00007f7a6d172893 in QWidgetPrivate::setVisible (this=0x558691a9d540, visible=<optimized out>) at kernel/qwidget.cpp:8383
#21 0x00007f7a6d16f648 in QWidgetPrivate::showChildren (this=this@entry=0x558692233f50, spontaneous=spontaneous@entry=false) at kernel/qwidget.cpp:8463
#22 0x00007f7a6d16f70f in QWidgetPrivate::show_helper (this=this@entry=0x558692233f50) at kernel/qwidget.cpp:8026
#23 0x00007f7a6d172893 in QWidgetPrivate::setVisible (this=0x558692233f50, visible=<optimized out>) at kernel/qwidget.cpp:8383
#24 0x00007f7a6d16f648 in QWidgetPrivate::showChildren (this=this@entry=0x5586918cf7f0, spontaneous=spontaneous@entry=false) at kernel/qwidget.cpp:8463
#25 0x00007f7a6d16f70f in QWidgetPrivate::show_helper (this=0x5586918cf7f0) at kernel/qwidget.cpp:8026
#26 0x00007f7a6d16f521 in QWidgetPrivate::show_recursive (this=<optimized out>) at kernel/qwidget.cpp:7950
#27 0x00007f7a6d16f630 in QWidgetPrivate::showChildren (this=this@entry=0x5586918e7550, spontaneous=spontaneous@entry=false) at kernel/qwidget.cpp:8461
#28 0x00007f7a6d16f70f in QWidgetPrivate::show_helper (this=this@entry=0x5586918e7550) at kernel/qwidget.cpp:8026
#29 0x00007f7a6d172893 in QWidgetPrivate::setVisible (this=0x5586918e7550, visible=<optimized out>) at kernel/qwidget.cpp:8383
#30 0x00007f7a6d16f648 in QWidgetPrivate::showChildren (this=this@entry=0x5586917c83b0, spontaneous=spontaneous@entry=false) at kernel/qwidget.cpp:8463
#31 0x00007f7a6d16f70f in QWidgetPrivate::show_helper (this=this@entry=0x5586917c83b0) at kernel/qwidget.cpp:8026
#32 0x00007f7a6d172893 in QWidgetPrivate::setVisible (this=0x5586917c83b0, visible=<optimized out>) at kernel/qwidget.cpp:8383
#33 0x00007f7a6d156417 in QStackedLayout::setCurrentIndex (this=this@entry=0x5586919306e0, index=1) at kernel/qstackedlayout.cpp:321
#34 0x00007f7a6d156724 in QStackedLayout::setCurrentWidget (this=0x5586919306e0, widget=widget@entry=0x5586918314d0) at kernel/qstackedlayout.cpp:376
#35 0x00007f7a6d2d7041 in QStackedWidget::setCurrentWidget (this=<optimized out>, widget=0x5586918314d0) at widgets/qstackedwidget.cpp:248
#36 0x00007f7a6e796aa0 in KPageViewPrivate::_k_pageSelected (this=0x558691969380, index=..., previous=...) at /usr/src/debug/kwidgetsaddons-5.71.0-lp152.1.1.x86_64/src/kpageview.cpp:273
#37 0x00007f7a6c0a2bf5 in QMetaObject::activate (sender=sender@entry=0x558691805790, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fffb9a754a0) at kernel/qobject.cpp:3804
#38 0x00007f7a6c0a3307 in QMetaObject::activate (sender=sender@entry=0x558691805790, m=m@entry=0x7f7a6c520680 <QItemSelectionModel::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fffb9a754a0) at kernel/qobject.cpp:3657
#39 0x00007f7a6c028727 in QItemSelectionModel::selectionChanged (this=this@entry=0x558691805790, _t1=..., _t2=...) at .moc/moc_qitemselectionmodel.cpp:458
#40 0x00007f7a6c02d290 in QItemSelectionModel::emitSelectionChanged (this=this@entry=0x558691805790, newSelection=..., oldSelection=...) at itemmodels/qitemselectionmodel.cpp:1871
#41 0x00007f7a6c0307db in QItemSelectionModel::select (this=0x558691805790, selection=..., command=...) at itemmodels/qitemselectionmodel.cpp:1338
#42 0x00007f7a6c02a78c in QItemSelectionModel::select (this=this@entry=0x558691805790, index=..., command=command@entry=...) at itemmodels/qitemselectionmodel.cpp:1188
#43 0x00007f7a6c028ad4 in QItemSelectionModel::setCurrentIndex (this=this@entry=0x558691805790, index=..., command=command@entry=...) at itemmodels/qitemselectionmodel.cpp:1413
#44 0x00007f7a6e79579a in KPageViewPrivate::updateSelection (this=<optimized out>) at /usr/src/debug/kwidgetsaddons-5.71.0-lp152.1.1.x86_64/src/kpageview.cpp:128
#45 0x00007f7a6e7968d5 in KPageViewPrivate::_k_modelChanged (this=0x558691969380) at /usr/src/debug/kwidgetsaddons-5.71.0-lp152.1.1.x86_64/src/kpageview.cpp:244
#46 0x00007f7a6c0a2bf5 in QMetaObject::activate (sender=sender@entry=0x5586916ecc50, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=3, argv=argv@entry=0x7fffb9a75900) at kernel/qobject.cpp:3804
#47 0x00007f7a6c0a3307 in QMetaObject::activate (sender=sender@entry=0x5586916ecc50, m=m@entry=0x7f7a6c520580 <QAbstractItemModel::staticMetaObject>, local_signal_index=local_signal_index@entry=3, argv=argv@entry=0x7fffb9a75900) at kernel/qobject.cpp:3657
#48 0x00007f7a6c01a2d6 in QAbstractItemModel::layoutChanged (this=this@entry=0x5586916ecc50, _t1=..., _t2=<optimized out>, _t2@entry=QAbstractItemModel::NoLayoutChangeHint) at .moc/moc_qabstractitemmodel.cpp:570
#49 0x00007f7a6e79cd26 in KPageWidgetModel::addPage (this=0x5586916ecc50, item=item@entry=0x558691733070) at /usr/src/debug/kwidgetsaddons-5.71.0-lp152.1.1.x86_64/src/kpagewidgetmodel.cpp:448
#50 0x00007f7a6e79b5fd in KPageWidget::addPage (this=<optimized out>, item=item@entry=0x558691733070) at /usr/src/debug/kwidgetsaddons-5.71.0-lp152.1.1.x86_64/src/kpagewidget.cpp:85
#51 0x00007f7a6fe9ab56 in ModuleView::addModule (this=this@entry=0x5586916d6ca0, module=0x5586918040c8) at /usr/src/debug/systemsettings5-5.18.5-lp152.1.2.x86_64/core/ModuleView.cpp:197
#52 0x00007f7a6fe9aedd in ModuleView::loadModule (this=0x5586916d6ca0, menuItem=...) at /usr/src/debug/systemsettings5-5.18.5-lp152.1.2.x86_64/core/ModuleView.cpp:150
#53 0x00007f7a6c0a2d0f in QtPrivate::QSlotObjectBase::call (a=0x7fffb9a75bb0, r=0x5586917aa8a0, this=0x5586915a8800) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:394
#54 QMetaObject::activate (sender=sender@entry=0x5586918cc430, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=3, argv=argv@entry=0x7fffb9a75bb0) at kernel/qobject.cpp:3784
#55 0x00007f7a6c0a3307 in QMetaObject::activate (sender=sender@entry=0x5586918cc430, m=m@entry=0x7f7a6d825c80 <QAbstractItemView::staticMetaObject>, local_signal_index=local_signal_index@entry=3, argv=argv@entry=0x7fffb9a75bb0) at kernel/qobject.cpp:3657
#56 0x00007f7a6d381ea5 in QAbstractItemView::activated (this=this@entry=0x5586918cc430, _t1=...) at .moc/moc_qabstractitemview.cpp:667
#57 0x00007f7a6d384f3e in QAbstractItemView::mouseReleaseEvent (this=this@entry=0x5586918cc430, event=event@entry=0x7fffb9a76570) at itemviews/qabstractitemview.cpp:1936
#58 0x00007f7a6d3c674f in QListView::mouseReleaseEvent (this=this@entry=0x5586918cc430, e=e@entry=0x7fffb9a76570) at itemviews/qlistview.cpp:798
#59 0x00007f7a6aea3f34 in KCategorizedView::mouseReleaseEvent (this=0x5586918cc430, event=0x7fffb9a76570) at /usr/src/debug/kitemviews-5.71.0-lp152.1.1.x86_64/src/kcategorizedview.cpp:1035
#60 0x00007f7a6d172d18 in QWidget::event (this=this@entry=0x5586918cc430, event=event@entry=0x7fffb9a76570) at kernel/qwidget.cpp:9343
#61 0x00007f7a6d215f2e in QFrame::event (this=0x5586918cc430, e=0x7fffb9a76570) at widgets/qframe.cpp:550
#62 0x00007f7a6d38ddf3 in QAbstractItemView::viewportEvent (this=0x5586918cc430, event=0x7fffb9a76570) at itemviews/qabstractitemview.cpp:1750
#63 0x00007f7a6c072e5d in QCoreApplicationPrivate::sendThroughObjectEventFilters (receiver=receiver@entry=0x558691887840, event=event@entry=0x7fffb9a76570) at kernel/qcoreapplication.cpp:1214
#64 0x00007f7a6d1329e5 in QApplicationPrivate::notify_helper (this=this@entry=0x5586912aa550, receiver=receiver@entry=0x558691887840, e=e@entry=0x7fffb9a76570) at kernel/qapplication.cpp:3695
#65 0x00007f7a6d13aef8 in QApplication::notify (this=<optimized out>, receiver=0x558691887840, e=0x7fffb9a76570) at kernel/qapplication.cpp:3161
#66 0x00007f7a6c0730d8 in QCoreApplication::notifyInternal2 (receiver=0x558691887840, event=0x7fffb9a76570) at kernel/qcoreapplication.cpp:1088
#67 0x00007f7a6c0732be in QCoreApplication::sendSpontaneousEvent (receiver=receiver@entry=0x558691887840, event=event@entry=0x7fffb9a76570) at kernel/qcoreapplication.cpp:1488
#68 0x00007f7a6d1394ef in QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0x558691887840, event=event@entry=0x7fffb9a76570, alienWidget=0x558691887840, nativeWidget=0x558691382450, buttonDown=buttonDown@entry=0x7f7a6d8368d0 <qt_button_down>, lastMouseReceiver=..., spontaneous=true, onlyDispatchEnterLeave=false) at kernel/qapplication.cpp:2647
#69 0x00007f7a6d18d9f1 in QWidgetWindow::handleMouseEvent (this=this@entry=0x55869159c6b0, event=event@entry=0x7fffb9a76a00) at kernel/qwidgetwindow.cpp:670
#70 0x00007f7a6d19084a in QWidgetWindow::event (this=0x55869159c6b0, event=0x7fffb9a76a00) at kernel/qwidgetwindow.cpp:289
#71 0x00007f7a6d132a0c in QApplicationPrivate::notify_helper (this=this@entry=0x5586912aa550, receiver=receiver@entry=0x55869159c6b0, e=e@entry=0x7fffb9a76a00) at kernel/qapplication.cpp:3701
#72 0x00007f7a6d13a020 in QApplication::notify (this=0x7fffb9a76e80, receiver=0x55869159c6b0, e=0x7fffb9a76a00) at kernel/qapplication.cpp:3447
#73 0x00007f7a6c0730d8 in QCoreApplication::notifyInternal2 (receiver=0x55869159c6b0, event=0x7fffb9a76a00) at kernel/qcoreapplication.cpp:1088
#74 0x00007f7a6c0732be in QCoreApplication::sendSpontaneousEvent (receiver=receiver@entry=0x55869159c6b0, event=event@entry=0x7fffb9a76a00) at kernel/qcoreapplication.cpp:1488
#75 0x00007f7a6c8e3b25 in QGuiApplicationPrivate::processMouseEvent (e=0x5586916f2280) at kernel/qguiapplication.cpp:2107
#76 0x00007f7a6c8e4e75 in QGuiApplicationPrivate::processWindowSystemEvent (e=e@entry=0x5586916f2280) at kernel/qguiapplication.cpp:1842
#77 0x00007f7a6c8be8fb in QWindowSystemInterface::sendWindowSystemEvents (flags=flags@entry=...) at kernel/qwindowsysteminterface.cpp:1151
#78 0x00007f7a5f4e13aa in xcbSourceDispatch (source=<optimized out>) at qxcbeventdispatcher.cpp:105
#79 0x00007f7a64cb2464 in g_main_dispatch (context=0x7f7a54004fa0) at ../glib/gmain.c:3216
#80 g_main_context_dispatch (context=context@entry=0x7f7a54004fa0) at ../glib/gmain.c:3881
#81 0x00007f7a64cb2800 in g_main_context_iterate (context=context@entry=0x7f7a54004fa0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:3954
#82 0x00007f7a64cb288c in g_main_context_iteration (context=0x7f7a54004fa0, may_block=may_block@entry=1) at ../glib/gmain.c:4015
#83 0x00007f7a6c0d017f in QEventDispatcherGlib::processEvents (this=0x558691370d00, flags=...) at kernel/qeventdispatcher_glib.cpp:422
#84 0x00007f7a6c07132a in QEventLoop::exec (this=this@entry=0x7fffb9a76da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:225
#85 0x00007f7a6c07a530 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1389
#86 0x0000558690167e00 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/systemsettings5-5.18.5-lp152.1.2.x86_64/app/main.cpp:70
[Inferior 1 (process 8101) detached]

The reporter indicates this bug may be a duplicate of or related to bug 426202.

Possible duplicates by query: bug 426202, bug 424778, bug 422963, bug 421846, bug 420787.

Reported using DrKonqi
Comment 1 ederag 2020-09-11 16:10:00 UTC 
Fixed by the following change in ~/.config/kdeglobals

-widgetStyle=bb10dark
+widgetStyle=Breeze
Comment 2 Christoph Feck 2020-09-11 18:07:26 UTC 
Yep, it's a crash in BB10 style.
Comment 3 ederag 2020-09-14 05:55:30 UTC 
The "resolved upstream" resolution is surprising.
Couldn't systemsettings catch the crash and revert ?
Comment 4 Christoph Feck 2020-09-14 10:05:49 UTC 
No, crashes caused by a broken QStyle can happen any time later in any application, not just in systemsettings.
Comment 5 ederag 2020-09-17 06:38:58 UTC 
Sure,
but since the buggy theme change was made in systemsettings,
I expected to be able to revert that change, in systemsettings as well.

Or by "upstream" do you mean that there is a general "theme handler"
that should catch the crash and allow to revert ? 
That would be even better of course.
(a quick "kde theming development" search did not show that information)
Comment 6 David Edmundson 2020-09-17 08:12:15 UTC 
Locally run systemsettings --style breeze to be able to reload


I don't see how we could technically catch this in systemsettings. If we crash, We crash. We can't exactly analyse why.

Upstream in this case is the BB10 style.