Fix potential crash when adding a group

Author: wonder-sk

src/gui/layertree/qgslayertreeview.cpp

@@ -224,7 +224,13 @@ QgsLayerTreeGroup* QgsLayerTreeView::currentGroupNode() const
     if ( QgsLayerTree::isGroup( parent ) )
       return QgsLayerTree::toGroup( node );
   }
-  // TODO: also handle if symbology is selected?
+
+  if ( QgsLayerTreeModelLegendNode* legendNode = layerTreeModel()->index2legendNode( selectionModel()->currentIndex() ) )
+  {
+    QgsLayerTreeLayer* parent = legendNode->parent();
+    if ( QgsLayerTree::isGroup( parent->parent() ) )
+      return QgsLayerTree::toGroup( parent->parent() );
+  }
 
   return 0;
 }

src/gui/layertree/qgslayertreeviewdefaultactions.cpp

@@ -113,6 +113,8 @@ QAction* QgsLayerTreeViewDefaultActions::actionGroupSelected( QObject* parent )
 void QgsLayerTreeViewDefaultActions::addGroup()
 {
   QgsLayerTreeGroup* group = mView->currentGroupNode();
+  if ( !group )
+    group = mView->layerTreeModel()->rootGroup();
 
   QgsLayerTreeGroup* newGroup = group->addGroup( uniqueGroupName( group ) );
   mView->edit( mView->layerTreeModel()->node2index( newGroup ) );
@@ -165,8 +167,12 @@ void QgsLayerTreeViewDefaultActions::zoomToLayer( QgsMapCanvas* canvas )
 
 void QgsLayerTreeViewDefaultActions::zoomToGroup( QgsMapCanvas* canvas )
 {
+  QgsLayerTreeGroup* groupNode = mView->currentGroupNode();
+  if ( !groupNode )
+    return;
+
   QList<QgsMapLayer*> layers;
-  foreach ( QString layerId, mView->currentGroupNode()->findLayerIds() )
+  foreach ( QString layerId, groupNode->findLayerIds() )
     layers << QgsMapLayerRegistry::instance()->mapLayer( layerId );
 
   zoomToLayers( canvas, layers );