QAccessibleTableCell stores QModelIndex

QAccessibleTableCell uses QModelIndex to store it internally. It causes seldom crashes when such indexes becomes invalid (due to batch delete from model).
In our case app crashes under Microsoft Test Manager after deleting couple of rows from QTreeView with custom data model:

 	Mdk.dll!mdk::SiteTreeModel::parent(const QModelIndex & i_index={...}) Line 175
 	Qt5Corematd.dll!QModelIndex::parent() Line 411
 	Qt5Widgetsmatd.dll!QTreeView::isIndexHidden(const QModelIndex & index={...}) Line 3044
 	Qt5Widgetsmatd.dll!QTreeView::visualRect(const QModelIndex & index={...}) Line 1106
 	Qt5Widgetsmatd.dll!QAccessibleTableCell::rect() Line 1057
 	Qt5Widgetsmatd.dll!QAccessibleTableCell::state() Line 1024
	qwindowsd.dll!QWindowsMsaaAccessible::get_accState(tagVARIANT varID, tagVARIANT * pvarState=0x000000000029ba30) Line 958

isIndexHidden called with index stored in QAccessibleTableCell and there is no object in model for QModelIndex::internalPointer.

As said in QModelIndex doc:

Note: Model indexes should be used immediately and then discarded. You should not rely on indexes to remain valid after calling model functions that change the structure of the model or delete items. If you need to keep a model index over time use a QPersistentModelIndex.