[5.2.x] Fixed #36181 -- Allowed Subquery usage in __in lookups against composite pks.

Thanks Jacob Walls for the report.

Backport of 8561100425876bde3be4b2a22324655f74ff9609 from main.

1 files changed, 5 insertions, 0 deletions

diff --git a/tests/composite_pk/test_filter.py b/tests/composite_pk/test_filter.py
index d4c6ef13e0..c633348cc1 100644
--- a/tests/composite_pk/test_filter.py
+++ b/tests/composite_pk/test_filter.py
@@ -442,6 +442,11 @@ class CompositePKFilterTests(TestCase):
         with self.assertRaisesMessage(ValueError, msg):
             Comment.objects.filter(text__gt=Cast(F("pk"), TextField())).count()
 
+    def test_explicit_subquery(self):
+        subquery = Subquery(User.objects.values("pk"))
+        self.assertEqual(User.objects.filter(pk__in=subquery).count(), 4)
+        self.assertEqual(Comment.objects.filter(user__in=subquery).count(), 5)
+
     def test_filter_case_when(self):
         msg = "When expression does not support composite primary keys."
         with self.assertRaisesMessage(ValueError, msg):