ERP5Workflow: fix testWorklist + add XXX comment

bt5/erp5_core_test/TestTemplateItem/portal_components/test.erp5.testWorklist.py

@@ -507,9 +507,9 @@ class TestWorklist(testWorkflowMixin):
     self.assertEqual(['Group1', 'Group2'], worklist_value.guard.groups)
     # expression
     worklist_value.setGuardExpression('')
-    self.assertEqual('', worklist_value.guard.expr)
+    self.assertEqual(None, worklist_value.guard.expr)
     worklist_value.setGuardExpression('python: "Hello, world"')
-    self.assertEqual(worklist_value.guard.expr, 'python: "Hello, world"')
+    self.assertEqual(worklist_value.guard.expr.text, 'python: "Hello, world"')
 
 def test_suite():
   suite = unittest.TestSuite()

product/ERP5Workflow/mixin/guardable.py

 from Products.DCWorkflow.Guard import Guard
+# XXX(WORKFLOW) ^ should not use DCWorkflow Guard class
 from Products.CMFCore.Expression import Expression
 
 class GuardableMixin(object):