Fixed #30493 -- Fixed prefetch_related() for GenericRelation with different content types.

Co-Authored-By: Mariusz Felisiak <felisiak.mariusz@gmail.com>

Thanks Simon Charette for the review.

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/generic_relations/tests.py b/tests/generic_relations/tests.py
index 2e99c5b5cf..7c0db95908 100644
--- a/tests/generic_relations/tests.py
+++ b/tests/generic_relations/tests.py
@@ -546,6 +546,24 @@ class GenericRelationsTests(TestCase):
         platypus.tags.remove(weird_tag)
         self.assertSequenceEqual(platypus.tags.all(), [furry_tag])
 
+    def test_prefetch_related_different_content_types(self):
+        TaggedItem.objects.create(content_object=self.platypus, tag='prefetch_tag_1')
+        TaggedItem.objects.create(
+            content_object=Vegetable.objects.create(name='Broccoli'),
+            tag='prefetch_tag_2',
+        )
+        TaggedItem.objects.create(
+            content_object=Animal.objects.create(common_name='Bear'),
+            tag='prefetch_tag_3',
+        )
+        qs = TaggedItem.objects.filter(
+            tag__startswith='prefetch_tag_',
+        ).prefetch_related('content_object', 'content_object__tags')
+        with self.assertNumQueries(4):
+            tags = list(qs)
+        for tag in tags:
+            self.assertSequenceEqual(tag.content_object.tags.all(), [tag])
+
 
 class ProxyRelatedModelTest(TestCase):
     def test_default_behavior(self):