Return error code in zonal statistics if operation canceled by user

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@15693 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/analysis/vector/qgszonalstatistics.cpp

@@ -209,6 +209,12 @@ int QgsZonalStatistics::calculateStatistics( QProgressDialog* p )
 
   GDALClose( inputDataset );
   mPolygonLayer->updateFieldMap();
+
+  if ( p && p->wasCanceled() )
+  {
+    return 9;
+  }
+
   return 0;
 }