Refs #28389 -- Added release note and test for pickling of LazyObject when…

Refs #28389 -- Added release note and test for pickling of LazyObject when wrapped object doesn't have __reduce__().

Forwardport of 30f334cc from stable/1.11.x

docs/releases/1.11.4.txt

@@ -15,3 +15,6 @@ Bugfixes
 
 * Fixed ``QuerySet.union()`` and ``difference()`` when combining with
   a queryset raising ``EmptyResultSet`` (:ticket:`28378`).
+
+* Fixed a regression in pickling of ``LazyObject`` on Python 2 when the wrapped
+  object doesn't have ``__reduce__()`` (:ticket:`28389`).

tests/utils_tests/test_lazyobject.py

@@ -184,11 +184,13 @@ class LazyObjectTestCase(TestCase):
     def test_pickle(self):
         # See ticket #16563
         obj = self.lazy_wrap(Foo())
+        obj.bar = 'baz'
         pickled = pickle.dumps(obj)
         unpickled = pickle.loads(pickled)
         self.assertIsInstance(unpickled, Foo)
         self.assertEqual(unpickled, obj)
         self.assertEqual(unpickled.foo, obj.foo)
+        self.assertEqual(unpickled.bar, obj.bar)
 
     # Test copying lazy objects wrapping both builtin types and user-defined
     # classes since a lot of the relevant code does __dict__ manipulation and