HelperContext provided to createObjectOutputStream is inadvertantly ignored

Ron Gavlin reported in http://www.mail-archive.com/tuscany-user@ws.apache.org/msg01884.html an issue with HelperContexts being unavailable during marshalling. I feel sure that this is due to this piece of code here in HelperProviderBase::ResolvableImpl#writeDataObject

XMLHelper xmlHelperLocal = xmlHelper;
if(objectOutput instanceof SDOObjectInputStream)

{ xmlHelperLocal = ((SDOObjectInputStream)objectOutput).getHelperContext().getXMLHelper(); }

xmlHelperLocal.save(dataObject, "commonj.sdo", "dataObject", gzipOutputStream);

where the instanceof test and cast should be to SDOObjectOutputStream