Strings in ERP5 must be stored as UTF-8, not unicode

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@22575 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Accessor/TypeDefinition.py

@@ -93,6 +93,8 @@ def asString(value):
       result = ''
     else:
       result = str(value)
+      if isinstance(result, unicode):
+        result = result.encode('utf-8')
   except TypeError:
     result = type_definition['string']['default']
   return result