Fixed #18463 -- Forced type() argument to be a byte string

django/db/models/query_utils.py

@@ -5,6 +5,7 @@ Factored out from django.db.models.query to avoid making the main module very
 large and/or so that they can be used by other modules without getting into
 circular import difficulties.
 """
+from __future__ import unicode_literals
 
 from django.db.backends import util
 from django.utils import tree
@@ -177,7 +178,7 @@ def deferred_class_factory(model, attrs):
     overrides["Meta"] = Meta
     overrides["__module__"] = model.__module__
     overrides["_deferred"] = True
-    return type(name, (model,), overrides)
+    return type(str(name), (model,), overrides)
 
 # The above function is also used to unpickle model instances with deferred
 # fields.

tests/regressiontests/defer_regress/tests.py

@@ -174,3 +174,10 @@ class DeferRegressionTest(TestCase):
         qs = ResolveThis.objects.defer('num')
         self.assertEqual(1, qs.count())
         self.assertEqual('Foobar', qs[0].name)
+
+    def test_deferred_class_factory(self):
+        from django.db.models.query_utils import deferred_class_factory
+        new_class = deferred_class_factory(Item,
+            ('this_is_some_very_long_attribute_name_so_modelname_truncation_is_triggered',))
+        self.assertEqual(new_class.__name__,
+            'Item_Deferred_this_is_some_very_long_attribute_nac34b1f495507dad6b02e2cb235c875e')