Merge topic 'samplefunction-fix'

ee3db155 Source was not setting the right key. Fixed.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Utkarsh Ayachit <utkarsh.ayachit@kitware.com>
Merge-request: !655

Imaging/Hybrid/vtkSampleFunction.cxx

@@ -400,6 +400,8 @@ int vtkSampleFunction::RequestInformation (
   vtkDataObject::
     SetPointDataActiveScalarInfo(outInfo,this->OutputScalarType,1);
 
+  outInfo->Set(vtkAlgorithm::CAN_PRODUCE_SUB_EXTENT(), 1);
+
   return 1;
 }