added test for Suor#353

tests/models.py

@@ -252,3 +252,19 @@ def contribute_to_class(self, cls, name, **kwargs):
 
 class CombinedFieldModel(models.Model):
     text = CombinedField(max_length=8, default='example')
+
+
+# 353
+class Foo(models.Model):
+    uid = models.UUIDField(default=uuid.uuid4)
+
+
+class Bar(models.Model):
+    uid = models.UUIDField(default=uuid.uuid4)
+    foo = models.OneToOneField(
+        to="Foo",
+        on_delete=models.SET_NULL,
+        related_name='related_foo',
+        blank=True,
+        null=True
+    )

tests/tests.py

@@ -597,6 +597,16 @@ def test_352(self):
         CombinedFieldModel.objects.create()
         list(CombinedFieldModel.objects.cache().all())
 
+    def test_353(self):
+        foo = Foo.objects.create()
+
+        bar = Bar.objects.create()
+
+        self.assertEqual(Foo.objects.cache().filter(related_foo__isnull=True).count(), 1)
+        bar.foo = foo
+        bar.save()
+        self.assertEqual(Foo.objects.cache().filter(related_foo__isnull=True).count(), 0)
+
 
 class RelatedTests(BaseTestCase):
     fixtures = ['basic']