QGIS » QGIS Application

To reproduce:
Rule based styling for a polyline layer (sourced from a geopackage)
Edit symbology for the rule
Save Symbol
Enter the name, keyword, check 'add to favourites'
Crash

From memory - same behavior exhibited in v3.2

Crash ID: ac98f8c965f6d138ca3fd9c781e7d1aeb1ea933c

Stack Trace

QBitArray::QBitArray :
QgsStyleModel::data :
QgsStyleProxyModel::filterAcceptsRow :
QSortFilterProxyModel::flags :
QSortFilterProxyModel::filterRole :
QSortFilterProxyModel::invalidateFilter :
QgsStyleModel::headerData :
QMetaObject::activate :
QgsStyle::entityTagsChanged :
QgsStyle::tagSymbol :
QgsStyle::saveSymbol :
QgsSymbolsListWidget::saveSymbol :
QMetaObject::activate :
QAbstractButton::clicked :
QAbstractButton::click :
QAbstractButton::mouseReleaseEvent :
QWidget::event :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QApplicationPrivate::sendMouseEvent :
QSizePolicy::QSizePolicy :
QSizePolicy::QSizePolicy :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QGuiApplicationPrivate::processMouseEvent :
QWindowSystemInterface::sendWindowSystemEvents :
QEventDispatcherWin32::processEvents :
CallWindowProcW :
DispatchMessageW :
QEventDispatcherWin32::processEvents :
qt_plugin_query_metadata :
QEventLoop::exec :
QCoreApplication::exec :
main :
BaseThreadInitThunk :
RtlUserThreadStart :

QGIS Info
QGIS Version: 3.4.0-Madeira
QGIS code revision: 4a4b62ed19
Compiled against Qt: 5.11.2
Running against Qt: 5.11.2
Compiled against GDAL: 2.3.2
Running against GDAL: 2.3.2

System Info
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 10.0.17134