clear layer rendering cache after appling a subset string

git-svn-id: http://svn.osgeo.org/qgis/trunk@13077 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: jef

src/core/qgsvectorlayer.cpp

@@ -1481,6 +1481,9 @@ bool QgsVectorLayer::setSubsetString( QString subset )
   mDataSource = mDataProvider->dataSourceUri();
   updateExtents();
 
+  if ( res )
+    setCacheImage( 0 );
+
   return res;
 }
 
@@ -3461,7 +3464,6 @@ bool QgsVectorLayer::commitChanges()
     emit editingStopped();
   }
 
-
   mDataProvider->updateExtents();
   mDataProvider->updateFeatureCount();