do not call setter in getter, because it is unexpected behaviour.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@41750 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Document.py

@@ -793,8 +793,6 @@ class Document(DocumentExtensibleTraversableMixin, XMLObject, UrlMixin,
     if self.hasFilename():
       return self._baseGetFilename(default)
     elif self.hasSourceReference():
-      filename = self._baseGetSourceReference(default)
-      self._setFilename(filename)
-      return filename
+      return self._baseGetSourceReference(default)
     else:
       return default