Fixed #33651 -- Added support for prefetching GenericForeignKey.

Co-authored-by: revanthgss <revanthgss@almabase.com>
Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>

tests/generic_relations/tests.py

@@ -1,6 +1,7 @@
 from django.contrib.contenttypes.models import ContentType
+from django.contrib.contenttypes.prefetch import GenericPrefetch
 from django.core.exceptions import FieldError
-from django.db.models import Q
+from django.db.models import Q, prefetch_related_objects
 from django.test import SimpleTestCase, TestCase, skipUnlessDBFeature
 
 from .models import (
@@ -747,6 +748,38 @@ class GenericRelationsTests(TestCase):
                 comparison.first_obj.comparisons.all(), [comparison]
             )
 
+    def test_generic_prefetch(self):
+        tagged_vegetable = TaggedItem.objects.create(
+            tag="great", content_object=self.bacon
+        )
+        tagged_animal = TaggedItem.objects.create(
+            tag="awesome", content_object=self.platypus
+        )
+        # Getting the instances again so that content object is deferred.
+        tagged_vegetable = TaggedItem.objects.get(pk=tagged_vegetable.pk)
+        tagged_animal = TaggedItem.objects.get(pk=tagged_animal.pk)
+
+        with self.assertNumQueries(2):
+            prefetch_related_objects(
+                [tagged_vegetable, tagged_animal],
+                GenericPrefetch(
+                    "content_object",
+                    [Vegetable.objects.all(), Animal.objects.only("common_name")],
+                ),
+            )
+        with self.assertNumQueries(0):
+            self.assertEqual(tagged_vegetable.content_object.name, self.bacon.name)
+        with self.assertNumQueries(0):
+            self.assertEqual(
+                tagged_animal.content_object.common_name,
+                self.platypus.common_name,
+            )
+        with self.assertNumQueries(1):
+            self.assertEqual(
+                tagged_animal.content_object.latin_name,
+                self.platypus.latin_name,
+            )
+
 
 class ProxyRelatedModelTest(TestCase):
     def test_default_behavior(self):