Predicate: Should not create PersitentMappings first time we see Predicate_view.

product/ERP5/tests/testPredicate.py

@@ -599,6 +599,22 @@ class TestPredicates(TestPredicateMixIn):
         test_tales_expression="python: 'france' in here.getRegion()")
     self.assertTrue(pred_true.test(doc))
 
+  def testPredicateViewWithOutModification(self):
+    """ Make sure Predicate_view wihout modification does not change
+        the object."""
+    predicate = self.createPredicate()
+    # when init Predicate, they are  nothing
+    self.assertTrue(getattr(predicate, '_identity_criterion', None) is None)
+    self.assertTrue(getattr(predicate, '_range_criterion', None) is None)
+    # just view it, does not create PersistentMapping
+    predicate.Predicate_view()
+    self.assertTrue(getattr(predicate, '_identity_criterion', None) is None)
+    self.assertTrue(getattr(predicate, '_range_criterion', None) is None)
+    # add property and view it, creates PersistentMapping
+    predicate.setCriterionPropertyList(['quantity'])
+    predicate.Predicate_view()
+    self.assertFalse(getattr(predicate, '_identity_criterion', None) is None)
+    self.assertFalse(getattr(predicate, '_range_criterion', None) is None)
 
 # TODO :
 #  multi membership category

product/ERP5Type/Core/Predicate.py

@@ -381,6 +381,10 @@ class Predicate(XMLObject):
       XXX - It would be better to return criteria in a Criterion class
             instance
     """
+    # We do not create PersistentMappings first time we *see* Predicate_view.
+    # Instead, we create them first time we modify Predicate document.
+    if not self.getCriterionPropertyList():
+      return []
     if getattr(aq_base(self), '_identity_criterion', None) is None:
       self._identity_criterion = PersistentMapping()
       self._range_criterion = PersistentMapping()