Refs #23947 -- Worked around a bug in Python that prevents deprecation warnings…

Refs #23947 -- Worked around a bug in Python that prevents deprecation warnings from appearing in tests.

django/test/utils.py

@@ -541,3 +541,17 @@ def captured_stdin():
        self.assertEqual(captured, "hello")
     """
     return captured_output("stdin")
+
+
+def reset_warning_registry():
+    """
+    Clear warning registry for all modules. This is required in some tests
+    because of a bug in Python that prevents warnings.simplefilter("always")
+    from always making warnings appear: http://bugs.python.org/issue4180
+
+    The bug was fixed in Python 3.4.2.
+    """
+    key = "__warningregistry__"
+    for mod in sys.modules.values():
+        if hasattr(mod, key):
+            getattr(mod, key).clear()

tests/deprecation/tests.py

@@ -5,6 +5,7 @@ import unittest
 import warnings
 
 from django.test import SimpleTestCase, RequestFactory, override_settings
+from django.test.utils import reset_warning_registry
 from django.utils import six, translation
 from django.utils.deprecation import RenameMethodsBase
 from django.utils.encoding import force_text
@@ -28,6 +29,7 @@ class RenameMethodsTests(SimpleTestCase):
         Ensure a warning is raised upon class definition to suggest renaming
         the faulty method.
         """
+        reset_warning_registry()
         with warnings.catch_warnings(record=True) as recorded:
             warnings.simplefilter('always')
 

tests/utils_tests/test_text.py

@@ -5,6 +5,7 @@ from unittest import skipUnless
 import warnings
 
 from django.test import SimpleTestCase
+from django.test.utils import reset_warning_registry
 from django.utils import six, text
 from django.utils.deprecation import RemovedInDjango19Warning
 from django.utils.encoding import force_text
@@ -219,6 +220,7 @@ class TestUtilsText(SimpleTestCase):
             self.assertEqual(text.javascript_quote(input), output)
 
     def test_deprecation(self):
+        reset_warning_registry()
         with warnings.catch_warnings(record=True) as w:
             warnings.simplefilter("always")
             text.javascript_quote('thingy')