Fixed a crash (clicking zoom to layer with no active layer)

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@15588 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: wonder

src/app/legend/qgslegend.cpp

@@ -1719,6 +1719,9 @@ void QgsLegend::legendLayerZoom()
 
   QgsLegendItem* li = dynamic_cast<QgsLegendItem *>( currentItem() );
 
+  if ( !li )
+    return;
+
   if ( li->type() == QgsLegendItem::LEGEND_LAYER )
   {
     QgsLegendLayer* currentLayer = dynamic_cast<QgsLegendLayer *>( currentItem() );

src/app/qgisapp.cpp

@@ -5790,11 +5790,13 @@ void QgisApp::activateDeactivateLayerRelatedActions( QgsMapLayer* layer )
     mActionLocalHistogramStretch->setEnabled( false );
     mActionFullHistogramStretch->setEnabled( false );
     mActionZoomActualSize->setEnabled( false );
+    mActionZoomToLayer->setEnabled( false );
     return;
   }
 
   mActionLayerProperties->setEnabled( true );
   mActionAddToOverview->setEnabled( true );
+  mActionZoomToLayer->setEnabled( true );
 
   /***********Vector layers****************/
   if ( layer->type() == QgsMapLayer::VectorLayer )