Fixed #21198 -- Prevented invalid use of @python_2_unicode_compatible.

Thanks jpic for the report and chmodas for working on a patch.

Reverts 2ea80b94. Refs #19362.

Conflicts:
	tests/utils_tests/test_encoding.py

1 files changed, 9 insertions, 1 deletions

diff --git a/tests/utils_tests/test_encoding.py b/tests/utils_tests/test_encoding.py
index 7aaba25a7a..df4ea1497a 100644
--- a/tests/utils_tests/test_encoding.py
+++ b/tests/utils_tests/test_encoding.py
@@ -2,7 +2,8 @@
 from __future__ import unicode_literals
 
 from django.utils import unittest
-from django.utils.encoding import force_bytes, filepath_to_uri
+from django.utils.encoding import force_bytes, filepath_to_uri, python_2_unicode_compatible
+from django.utils import six
 
 
 class TestEncodingUtils(unittest.TestCase):
@@ -21,3 +22,10 @@ class TestEncodingUtils(unittest.TestCase):
             'upload/%D1%87%D1%83%D0%B1%D0%B0%D0%BA%D0%B0.mp4')
         self.assertEqual(filepath_to_uri('upload\\чубака.mp4'.encode('utf-8')),
             'upload/%D1%87%D1%83%D0%B1%D0%B0%D0%BA%D0%B0.mp4')
+
+    @unittest.skipIf(six.PY3, "tests a class not defining __str__ under Python 2")
+    def test_decorated_class_without_str(self):
+        with self.assertRaises(ValueError):
+            @python_2_unicode_compatible
+            class NoStr(object):
+                pass