Make the portal parameter optional for compatibility.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@20890 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Utils.py

@@ -999,10 +999,13 @@ def setDefaultConstructor(klass):
       document_constructor.__name__ = document_constructor_name
 
 
-def createExpressionContext(object, portal):
+def createExpressionContext(object, portal=None):
   """
     Return a context used for evaluating a TALES expression.
   """
+  if portal is None and object is not None:
+    portal = object.getPortalObject()
+
   if object is None or getattr(object, 'aq_base', None) is None:
     folder = portal
   else: