Merge pull request #218 from alexander-alvarez/master

Issue #213: Don't modify Q passed in as arguments

polymorphic/query.py

@@ -112,9 +112,9 @@ class PolymorphicQuerySet(QuerySet):
 
     def _filter_or_exclude(self, negate, *args, **kwargs):
         "We override this internal Django functon as it is used for all filter member functions."
-        translate_polymorphic_filter_definitions_in_args(self.model, args, using=self._db)  # the Q objects
+        q_objects = translate_polymorphic_filter_definitions_in_args(self.model, args, using=self._db)  # the Q objects
         additional_args = translate_polymorphic_filter_definitions_in_kwargs(self.model, kwargs, using=self._db)  # filter_field='data'
-        return super(PolymorphicQuerySet, self)._filter_or_exclude(negate, *(list(args) + additional_args), **kwargs)
+        return super(PolymorphicQuerySet, self)._filter_or_exclude(negate, *(list(q_objects) + additional_args), **kwargs)
 
     def order_by(self, *args, **kwargs):
         """translate the field paths in the args, then call vanilla order_by."""
@@ -472,3 +472,4 @@ class PolymorphicQuerySet(QuerySet):
             return olist
         clist = PolymorphicQuerySet._p_list_class(olist)
         return clist
+

polymorphic/query_translate.py

@@ -93,17 +93,16 @@ def translate_polymorphic_filter_definitions_in_args(queryset_model, args, using
     """
     Translate the non-keyword argument list for PolymorphicQuerySet.filter()
 
-    In the args list, we replace all kwargs to Q-objects that contain special
+    In the args list, we return all kwargs to Q-objects that contain special
     polymorphic functionality with their vanilla django equivalents.
     We traverse the Q object tree for this (which is simple).
 
-    TODO: investigate: we modify the Q-objects ina args in-place. Is this OK?
 
-    Modifies: args list
+    Returns: modified Q objects
     """
+    q_objects = [q if django.VERSION < (1, 6) else q.clone() for q in args]
+    return [translate_polymorphic_Q_object(queryset_model, q, using=using) for q in q_objects]
 
-    for q in args:
-        translate_polymorphic_Q_object(queryset_model, q, using=using)
 
 
 def _translate_polymorphic_filter_definition(queryset_model, field_path, field_val, using=DEFAULT_DB_ALIAS):
@@ -266,3 +265,4 @@ def _create_model_filter_Q(modellist, not_instance_of=False, using=DEFAULT_DB_AL
     if not_instance_of:
         q_ored = ~q_ored
     return q_ored
+

polymorphic/tests.py

@@ -824,6 +824,24 @@ class PolymorphicTests(TestCase):
         self.assertEqual(repr(objects[0]), '<Model2B: id 2, field1 (CharField), field2 (CharField)>')
         self.assertEqual(repr(objects[1]), '<Model2C: id 3, field1 (CharField), field2 (CharField), field3 (CharField)>')
 
+    @skipIf(django.VERSION < (1, 6), "Django 1.4 and 1.5 don't support q.clone()")
+    def test_query_filter_exclude_is_immutable(self):
+        # given
+        q_to_reuse = Q(Model2B___field2='something')
+        untouched_q_object = Q(Model2B___field2='something')
+        # when
+        Model2A.objects.filter(q_to_reuse).all()
+        # then
+        self.assertEquals(q_to_reuse.children, untouched_q_object.children)
+
+        # given
+        q_to_reuse = Q(Model2B___field2='something')
+        untouched_q_object = Q(Model2B___field2='something')
+        # when
+        Model2B.objects.filter(q_to_reuse).all()
+        # then
+        self.assertEquals(q_to_reuse.children, untouched_q_object.children)
+
     def test_polymorphic___filter_field(self):
         p = ModelUnderRelParent.objects.create(_private=True, field1='AA')
         ModelUnderRelChild.objects.create(parent=p, _private2=True)
@@ -1110,32 +1128,32 @@ class PolymorphicTests(TestCase):
 
         # test that we can delete the object
         t.delete()
-        
+
     def test_polymorphic__aggregate(self):
         """ test ModelX___field syntax on aggregate (should work for annotate either) """
-        
+
         Model2A.objects.create(field1='A1')
         Model2B.objects.create(field1='A1', field2='B2')
         Model2B.objects.create(field1='A1', field2='B2')
-        
+
         # aggregate using **kwargs
         result = Model2A.objects.aggregate(cnt=Count('Model2B___field2'))
         self.assertEqual(result, {'cnt': 2})
-        
+
         # aggregate using **args
         with self.assertRaisesMessage(AssertionError, 'PolymorphicModel: annotate()/aggregate(): ___ model lookup supported for keyword arguments only'):
             Model2A.objects.aggregate(Count('Model2B___field2'))
-        
+
-        
+
-        
+
     @skipIf(django.VERSION < (1,8,), "This test needs Django >=1.8")
     def test_polymorphic__complex_aggregate(self):
         """ test (complex expression on) aggregate (should work for annotate either) """
-        
+
         Model2A.objects.create(field1='A1')
         Model2B.objects.create(field1='A1', field2='B2')
         Model2B.objects.create(field1='A1', field2='B2')
-        
+
         # aggregate using **kwargs
         result = Model2A.objects.aggregate(
             cnt_a1=Count(Case(When(field1='A1', then=1))),
@@ -1150,7 +1168,7 @@ class PolymorphicTests(TestCase):
             complexagg = Count(expression)*10
             complexagg.default_alias = 'complexagg'
             return complexagg
-        
+
         with self.assertRaisesMessage(AssertionError, 'PolymorphicModel: annotate()/aggregate(): ___ model lookup supported for keyword arguments only'):
             Model2A.objects.aggregate(ComplexAgg('Model2B___field2'))
 
@@ -1169,7 +1187,7 @@ class PolymorphicTests(TestCase):
         Model2C(field1='C1', field2='C2', field3='C3').save(using='secondary')
         Model2B.objects.create(field1='B1', field2='B2')
         Model2D(field1='D1', field2='D2', field3='D3', field4='D4').save('secondary')
-        
+
         default_objects = list(Model2A.objects.order_by('id'))
         self.assertEqual(len(default_objects), 2)
         self.assertEqual(repr(default_objects[0]), '<Model2B: id 1, field1 (CharField), field2 (CharField)>')
@@ -1224,3 +1242,4 @@ class RegressionTests(TestCase):
 
         expected_queryset = [bottom]
         self.assertQuerysetEqual(Bottom.objects.all(), [repr(r) for r in expected_queryset])
+