RealDataSelectorWidget: handle unselected case

GUI/View/Import/RealDataSelectorWidget.cpp

@@ -158,6 +158,8 @@ void RealDataSelectorWidget::setCurrentItem(RealItem* item)
 
 QModelIndex RealDataSelectorWidget::currentIndex()
 {
+    if (!m_itemTree->selectionModel()->isSelected(m_itemTree->selectionModel()->currentIndex()))
+        return QModelIndex();
     return m_itemTree->selectionModel()->currentIndex();
 }