Fixed #22023 -- Raised an error for values() followed by defer() or only().

Previously, doing so resulted in invalid data or crash.

Thanks jtiai for the report and Karol Jochelson,
Jakub Nowak, Loic Bistuer, and Baptiste Mispelon for reviews.

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/queries/tests.py b/tests/queries/tests.py
index 3f861db5d1..7bb5bb34d0 100644
--- a/tests/queries/tests.py
+++ b/tests/queries/tests.py
@@ -1275,6 +1275,16 @@ class Queries3Tests(BaseQuerysetTest):
             Item.objects.datetimes, 'name', 'month'
         )
 
+    def test_ticket22023(self):
+        # only() and defer() are not applicable for ValuesQuerySet
+        with self.assertRaisesMessage(NotImplementedError,
+                "ValuesQuerySet does not implement only()"):
+            Valid.objects.values().only()
+
+        with self.assertRaisesMessage(NotImplementedError,
+                "ValuesQuerySet does not implement defer()"):
+            Valid.objects.values().defer()
+
 
 class Queries4Tests(BaseQuerysetTest):
     def setUp(self):