[2.0.x] Fixed #28742 -- Fixed AttributeError crash when assigning None to cached reverse relations.

Backport of fcfcf8aae470d893b0d2ef176434461edf9e9c4d from master

1 files changed, 9 insertions, 0 deletions

diff --git a/tests/one_to_one/tests.py b/tests/one_to_one/tests.py
index 65257cf7dc..314c56a60f 100644
--- a/tests/one_to_one/tests.py
+++ b/tests/one_to_one/tests.py
@@ -196,6 +196,15 @@ class OneToOneTests(TestCase):
         # UndergroundBar.
         p.undergroundbar = None
 
+    def test_assign_none_to_null_cached_reverse_relation(self):
+        p = Place.objects.get(name='Demon Dogs')
+        # Prime the relation's cache with a value of None.
+        with self.assertRaises(Place.undergroundbar.RelatedObjectDoesNotExist):
+            getattr(p, 'undergroundbar')
+        # Assigning None works if there isn't a related UndergroundBar and the
+        # reverse cache has a value of None.
+        p.undergroundbar = None
+
     def test_related_object_cache(self):
         """ Regression test for #6886 (the related-object cache) """