Fixed #21787 -- regression in MTI .exclude() queries

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/queries/tests.py b/tests/queries/tests.py
index 03cfc71afe..b303d5f603 100644
--- a/tests/queries/tests.py
+++ b/tests/queries/tests.py
@@ -3225,3 +3225,21 @@ class ValuesJoinPromotionTests(TestCase):
         self.assertEqual(qs.count(), 1)
         tblname = connection.ops.quote_name(ObjectB._meta.db_table)
         self.assertTrue(' LEFT OUTER JOIN %s' % tblname in str(qs.query))
+
+
+class ForeignKeyToBaseExcludeTests(TestCase):
+    def test_ticket_21787(self):
+        sc1 = SpecialCategory.objects.create(special_name='sc1', name='sc1')
+        sc2 = SpecialCategory.objects.create(special_name='sc2', name='sc2')
+        sc3 = SpecialCategory.objects.create(special_name='sc3', name='sc3')
+        c1 = CategoryItem.objects.create(category=sc1)
+        CategoryItem.objects.create(category=sc2)
+        self.assertQuerysetEqual(
+            SpecialCategory.objects.exclude(
+                categoryitem__id=c1.pk).order_by('name'),
+            [sc2, sc3], lambda x: x
+        )
+        self.assertQuerysetEqual(
+            SpecialCategory.objects.filter(categoryitem__id=c1.pk),
+            [sc1], lambda x: x
+        )