Fixed #12885 -- Fixed queries with GenericRelations to multi-table inheritance child models.

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/generic_relations/tests.py b/tests/generic_relations/tests.py
index 3d3e2acfe5..1d3d3d373b 100644
--- a/tests/generic_relations/tests.py
+++ b/tests/generic_relations/tests.py
@@ -405,6 +405,13 @@ class GenericRelationsTests(TestCase):
         # GenericRelations to models that use multi-table inheritance work.
         granite = ValuableRock.objects.create(name='granite', hardness=5)
         ValuableTaggedItem.objects.create(content_object=granite, tag="countertop", value=1)
+        self.assertEqual(ValuableRock.objects.filter(tags__value=1).count(), 1)
+        # We're generating a slightly inefficient query for tags__tag - we
+        # first join ValuableRock -> TaggedItem -> ValuableTaggedItem, and then
+        # we fetch tag by joining TaggedItem from ValuableTaggedItem. The last
+        # join isn't necessary, as TaggedItem <-> ValuableTaggedItem is a
+        # one-to-one join.
+        self.assertEqual(ValuableRock.objects.filter(tags__tag="countertop").count(), 1)
         granite.delete()  # deleting the rock should delete the related tag.
         self.assertEqual(ValuableTaggedItem.objects.count(), 0)