[1.8.x] Fixed #24744 - Fixed relabeled_clone for the Transform

Backport of 08232ef84d from master

django/db/models/lookups.py

@@ -72,8 +72,13 @@ class Transform(RegisterLookupMixin):
     def output_field(self):
         return self.lhs.output_field
 
+    def copy(self):
+        return copy(self)
+
     def relabeled_clone(self, relabels):
-        return self.__class__(self.lhs.relabeled_clone(relabels))
+        copy = self.copy()
+        copy.lhs = self.lhs.relabeled_clone(relabels)
+        return copy
 
     def get_group_by_cols(self):
         return self.lhs.get_group_by_cols()

docs/releases/1.8.3.txt

@@ -57,3 +57,5 @@ Bugfixes
 * Corrected join promotion for multiple ``Case`` expressions. Annotating a
   query with multiple  ``Case`` expressions could unexpectedly filter out
   results (:ticket:`24924`).
+
+* Fixed usage of transforms in subqueries (:ticket:`24744`).

tests/custom_lookups/tests.py

@@ -557,3 +557,18 @@ class CustomisedMethodsTests(TestCase):
     def test_overridden_get_transform_chain(self):
         q = CustomModel.objects.filter(field__transformfunc_banana__transformfunc_pear=3)
         self.assertIn('pear()', str(q.query))
+
+
+class SubqueryTransformTests(TestCase):
+    def test_subquery_usage(self):
+        models.IntegerField.register_lookup(Div3Transform)
+        try:
+            Author.objects.create(name='a1', age=1)
+            a2 = Author.objects.create(name='a2', age=2)
+            Author.objects.create(name='a3', age=3)
+            Author.objects.create(name='a4', age=4)
+            self.assertQuerysetEqual(
+                Author.objects.order_by('name').filter(id__in=Author.objects.filter(age__div3=2)),
+                [a2], lambda x: x)
+        finally:
+            models.IntegerField._unregister_lookup(Div3Transform)