QItemSelectionModel::clearSelection() should be virtual

QItemSelectionModel::clear() is virtual, allowing the user to customize the clear operation e.g. to provide additional housekeeping to be executed. However, QItemSelectionModel::clearSelection() is not virtual, so if any code calls this, the additional derived-class behaviour of clear() is never executed.
I would suggest just making the clearSelection() slot also virtual; or make both non-virtual!