Ticket #18174: ticket_18174_tests.diff

tests/regressiontests/queries/models.py

@@ -357 +357 @@
 
     class Meta:
         ordering = ['id']
+
+
+class Base1(models.Model):
+    b1_id = models.AutoField(primary_key=True)
+    b1_desc = models.CharField(max_length=100, null=True)
+
+class Base2(models.Model):
+    b2_id = models.AutoField(primary_key=True)
+    b2_desc = models.CharField(max_length=100, null=True)
+
+class Base3(models.Model):
+    b3_id = models.AutoField(primary_key=True)
+    b3_desc = models.CharField(max_length=100, null=True)
+
+class Middle(Base1, Base2, Base3):
+    m_desc = models.CharField(max_length=100, null=True)
+
+class Top(Middle):
+    t_desc = models.CharField(max_length=100)

tests/regressiontests/queries/tests.py

@@ -23 +23 @@
     Ranking, Related, Report, ReservedName, Tag, TvChef, Valid, X, Food, Eaten,
     Node, ObjectA, ObjectB, ObjectC, CategoryItem, SimpleCategory,
     SpecialCategory, OneToOneCategory, NullableName, ProxyCategory,
-    SingleObject, RelatedObject)
+    SingleObject, RelatedObject, Top, Base1)
 
 
 class BaseQuerysetTest(TestCase):
@@ -847 +847 @@
         )
         Tag._meta.ordering = original_ordering
 
+    def test_ticket18174(self):
+        """
+        Check that in a model like this:
+                         / Base1
+            Top -> Middle- Base2
+                         \ Base3
+
+        The joins are done from Top to Middle to Base1, Base2, Base3.
+        """
+        Base1.objects.create()
+        Top.objects.create(t_desc='foo')
+        qs = Top.objects.all()
+        # The joins to the parent tables are added only when the query is
+        # evaluated.
+        results = list(qs)
+        self.assertEqual(qs.query.alias_map['queries_base1'].lhs_alias, 'queries_middle')
+        self.assertEqual(len(results), 1)
+
     def test_exclude(self):
         self.assertQuerysetEqual(
             Item.objects.exclude(tags__name='t4'),