Fixed #35044 -- Avoided clearing reverse relations and private fields when accessing deferred fields.

Regression in a7b5ad8b19a08d7d57302ece74f6e26d2887fd9f for reverse
relations and possibly in 123b1d3fcf79f091573c40be6da7113a6ef35b62 for
private fields.

1 files changed, 35 insertions, 0 deletions

diff --git a/tests/contenttypes_tests/test_fields.py b/tests/contenttypes_tests/test_fields.py
index 5510f34cd0..15f1dafd63 100644
--- a/tests/contenttypes_tests/test_fields.py
+++ b/tests/contenttypes_tests/test_fields.py
@@ -45,6 +45,18 @@ class GenericForeignKeyTests(TestCase):
         new_entity = answer.question
         self.assertIsNot(old_entity, new_entity)
 
+    def test_clear_cached_generic_relation_explicit_fields(self):
+        question = Question.objects.create(text="question")
+        answer = Answer.objects.create(text="answer", question=question)
+        old_question_obj = answer.question
+        # The reverse relation is not refreshed if not passed explicitly in
+        # `fields`.
+        answer.refresh_from_db(fields=["text"])
+        self.assertIs(answer.question, old_question_obj)
+        answer.refresh_from_db(fields=["question"])
+        self.assertIsNot(answer.question, old_question_obj)
+        self.assertEqual(answer.question, old_question_obj)
+
 
 class GenericRelationTests(TestCase):
     def test_value_to_string(self):
@@ -55,6 +67,29 @@ class GenericRelationTests(TestCase):
         self.assertCountEqual(result, [answer1.pk, answer2.pk])
 
 
+class DeferredGenericRelationTests(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        cls.question = Question.objects.create(text="question")
+        cls.answer = Answer.objects.create(text="answer", question=cls.question)
+
+    def test_defer_not_clear_cached_private_relations(self):
+        obj = Answer.objects.defer("text").get(pk=self.answer.pk)
+        with self.assertNumQueries(1):
+            obj.question
+        obj.text  # Accessing a deferred field.
+        with self.assertNumQueries(0):
+            obj.question
+
+    def test_only_not_clear_cached_private_relations(self):
+        obj = Answer.objects.only("content_type", "object_id").get(pk=self.answer.pk)
+        with self.assertNumQueries(1):
+            obj.question
+        obj.text  # Accessing a deferred field.
+        with self.assertNumQueries(0):
+            obj.question
+
+
 class GetPrefetchQuerySetDeprecation(TestCase):
     def test_generic_relation_warning(self):
         Question.objects.create(text="test")