From 6ae466732c6a5cd988d02110ab0538c7752a3253 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Langa?= <lukasz@langa.pl>
Date: Wed, 24 Apr 2013 01:49:52 +0200
Subject: [PATCH] clean the environment from pre-existing PYTHONWARNINGS for
 test_warnings

---
 Lib/unittest/test/test_runner.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Lib/unittest/test/test_runner.py b/Lib/unittest/test/test_runner.py
index aed1e76940a..e22e6bc279e 100644
--- a/Lib/unittest/test/test_runner.py
+++ b/Lib/unittest/test/test_runner.py
@@ -139,6 +139,18 @@ class TestCleanUp(unittest.TestCase):
 class Test_TextTestRunner(unittest.TestCase):
     """Tests for TextTestRunner."""
 
+    def setUp(self):
+        # clean the environment from pre-existing PYTHONWARNINGS to make
+        # test_warnings results consistent
+        self.pythonwarnings = os.environ.get('PYTHONWARNINGS')
+        if self.pythonwarnings:
+            del os.environ['PYTHONWARNINGS']
+
+    def tearDown(self):
+        # bring back pre-existing PYTHONWARNINGS if present
+        if self.pythonwarnings:
+            os.environ['PYTHONWARNINGS'] = self.pythonwarnings
+
     def test_init(self):
         runner = unittest.TextTestRunner()
         self.assertFalse(runner.failfast)