Created attachment 120650 [details]
Possible patch to keep m_paintOrder in synch with m_visiblePlacemarks

SUMMARY
Marble applications 19.04 compiled from sources on Windows 10 64 bit
Qt 5.11.2 64 bit
Visual Studio 2015
The crash happens only in the debug version, but it might be due to the speed difference, please see additional information

STEPS TO REPRODUCE
1. Start Marble with the default OSM map (earth/openstreetmap/openstreetmap.dgml)
2. Show the annotate plugin toolbar and select "add placemark"
3. In the Add Placemark dialog change a coordinate
4. Move the dialog and move the mouse pointer on the map below

OBSERVED RESULT
The application crashes with the following call stack:

 	Qt5Guid.dll!QPlatformPixmap::height() Line 124	
 	Qt5Guid.dll!QPixmap::size() Line 532	
>	marblewidget-qt5d.dll!Marble::VisiblePlacemark::symbolRect() Line 171	
 	marblewidget-qt5d.dll!Marble::PlacemarkLayout::hasPlacemarkAt(const QPoint & pos) Line 556	
 	marblewidget-qt5d.dll!Marble::PlacemarkLayer::hasPlacemarkAt(const QPoint & pos) Line 219	
 	marblewidget-qt5d.dll!Marble::MarbleMap::hasFeatureAt(const QPoint & position) Line 483	
 	marblewidget-qt5d.dll!Marble::MarbleDefaultInputHandler::adjustCursorShape(const QPoint & mousePosition, const QPoint & mouseDirection) Line 663	
 	marblewidget-qt5d.dll!Marble::MarbleDefaultInputHandler::handleMouseEvent(QMouseEvent * event) Line 884	
 	marblewidget-qt5d.dll!Marble::MarbleDefaultInputHandler::eventFilter(QObject * o, QEvent * e) Line 923	
 	Qt5Cored.dll!QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject * receiver, QEvent * event) Line 1174	
 	Qt5Widgetsd.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3723	
 	Qt5Widgetsd.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3203	
 	Qt5Cored.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1048	
 	Qt5Cored.dll!QCoreApplication::sendSpontaneousEvent(QObject * receiver, QEvent * event) Line 237	
 	Qt5Widgetsd.dll!QApplicationPrivate::sendMouseEvent(QWidget * receiver, QMouseEvent * event, QWidget * alienWidget, QWidget * nativeWidget, QWidget * * buttonDown, QPointer<QWidget> & lastMouseReceiver, bool spontaneous) Line 2693	
 	Qt5Widgetsd.dll!QWidgetWindow::handleMouseEvent(QMouseEvent * event) Line 661	
 	Qt5Widgetsd.dll!QWidgetWindow::event(QEvent * event) Line 282	
 	Qt5Widgetsd.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3727	
 	Qt5Widgetsd.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3099	
 	Qt5Cored.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1048	
 	Qt5Cored.dll!QCoreApplication::sendSpontaneousEvent(QObject * receiver, QEvent * event) Line 237	
 	Qt5Guid.dll!QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent * e) Line 2082	
 	Qt5Guid.dll!QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent * e) Line 1817	
 	Qt5Guid.dll!QWindowSystemInterface::sendWindowSystemEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 1038	
 	qwindowsd.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 83	
 	Qt5Cored.dll!qt_internal_proc(HWND__ * hwnd, unsigned int message, unsigned __int64 wp, __int64 lp) Line 239	
 	[External Code]	
 	Qt5Cored.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 630	
 	qwindowsd.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 74	
 	Qt5Cored.dll!QEventLoop::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 137	
 	Qt5Cored.dll!QEventLoop::exec(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 214	
 	Qt5Cored.dll!QCoreApplication::exec() Line 1336	
 	Qt5Guid.dll!QGuiApplication::exec() Line 1762	
 	Qt5Widgetsd.dll!QApplication::exec() Line 2902	
 	marble-qt.exe!main(int argc, char * * argv) Line 308	
 	[External Code]	

EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 10 64 bit
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 5.11.2 64bit

ADDITIONAL INFORMATION
The crash seems to happen because the mouse movement triggers an updateFeature:

 AnnotatePlugin::eventFilter
  -> AnnotatePlugin::handleUncaughtEvents
	-> m_marbleWidget->model()->treeModel()->updateFeature( m_focusItem->placemark() );

Which in turn calls RemoveFeature and AddFeature of GeoDataTreeModel and they emits rowsAboutToBeRemoved and rowsInserted signals, connected to removePlacemarks and addPlacemarks of PlacemarkLayout
   
PlacemarkLayout::removePlacemarks
	-> remove the placemark from its cache and the associated VisibleItem. It doesn't deal with m_paintOrder.

PlacemarkLayout::addPlacemarks
	-> add only the placemark to the internal cache. Creation of VisibleItem seems to be demanded to the first layoutPlacemark call
	
At the end of addPlacemark an emit repaintNeeded() should cause a PlacemarkLayout::layoutPlacemark call, if that happens before any other mouse events, all is well.

But if the mouse event is passed to MarbleDefaultInputHandler::eventFilter before the next render, then the following calls cause an invalid memory access.
MarbleDefaultInputHandler::eventFilter
	-> MarbleDefaultInputHandler::adjustCursorShape
		-> MarbleInputHandler::d->m_marblePresenter->map()->hasFeatureAt(mousePosition)
		-> ...
		-> PlacemarkLayout::hasPlacemarkAt which uses m_paintOrder still containing an invalid VisibleItem from the preceding removePlacemarks
I don't understand in detail the reasone of the debug/relase difference, but it would seem a sound and roboust approach to make PlacemarkLayout::m_paintOrder more in synch with m_visiblePlacemarks.