Avoid failure when calling hasData as Document object does not have

'data' property defined by default


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@32281 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Document.py

@@ -1276,7 +1276,7 @@ class Document(PermanentURLMixIn, XMLObject, UrlMixIn, CachedConvertableMixin, S
       using the base_data property. Refer to Document.py propertysheet.
       Use accessors (getBaseData, setBaseData, hasBaseData, etc.)
     """
-    if not self.hasData():
+    if getattr(self, 'hasData', None) is not None and not self.hasData():
       # Empty document cannot be converted
       return #'Document is empty'
     try: