Index: python/plugins/fTools/tools/doGeometry.py
===================================================================
--- python/plugins/fTools/tools/doGeometry.py	(revision 13425)
+++ python/plugins/fTools/tools/doGeometry.py	(working copy)
@@ -169,6 +169,10 @@
       QMessageBox.warning( self, self.tr("Geometry"), self.tr("Error processing specified tolerance!\nPlease choose larger tolerance...") )
       if not QgsVectorFileWriter.deleteShapeFile( self.shapefileName ):
         QMessageBox.warning( self, self.tr("Geometry"), self.tr( "Unable to delete incomplete shapefile." ) )
+    elif success == "attr_error":
+      QMessageBox.warning( self, self.tr("Geometry"), self.tr("At least two features must have same attribute value!\nPlease choose another field...") )
+      if not QgsVectorFileWriter.deleteShapeFile( self.shapefileName ):
+        QMessageBox.warning( self, self.tr("Geometry"), self.tr( "Unable to delete incomplete shapefile." ) )
     else:
       self.cancel_close.setText( "Close" )
       QObject.disconnect( self.cancel_close, SIGNAL( "clicked()" ), self.cancelThread )
@@ -267,6 +271,8 @@
         outFeat.setGeometry( outGeom )
         writer.addFeature( outFeat )
       del writer
+    else:
+      return "attr_error"
     return True

   def multi_to_single( self ):