From d23ea06175c62b166d8a6c7a2efc090bf7ead779 Mon Sep 17 00:00:00 2001
From: Michael Foord <fuzzyman@voidspace.org.uk>
Date: Sun, 2 May 2010 21:00:22 +0000
Subject: [PATCH] Merged revisions 80708 via svnmerge from
 svn+ssh://pythondev@svn.python.org/python/trunk

........
  r80708 | michael.foord | 2010-05-02 21:39:42 +0100 (Sun, 02 May 2010) | 1 line

  Fix unittest tests to not abuse traceback.format_exception
........
---
 Lib/unittest/result.py           |  4 +---
 Lib/unittest/test/test_result.py | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/Lib/unittest/result.py b/Lib/unittest/result.py
index 92b1f91a147..1dbd04cf752 100644
--- a/Lib/unittest/result.py
+++ b/Lib/unittest/result.py
@@ -153,9 +153,7 @@ class TestResult(object):
             length = self._count_relevant_tb_levels(tb)
             msgLines = traceback.format_exception(exctype, value, tb, length)
         else:
-            chain = exctype is not None
-            msgLines = traceback.format_exception(exctype, value, tb,
-                                                  chain=chain)
+            msgLines = traceback.format_exception(exctype, value, tb)
 
         if self.buffer:
             output = sys.stdout.getvalue()
diff --git a/Lib/unittest/test/test_result.py b/Lib/unittest/test/test_result.py
index c7030325ac0..64798a1098e 100644
--- a/Lib/unittest/test/test_result.py
+++ b/Lib/unittest/test/test_result.py
@@ -4,6 +4,7 @@ import textwrap
 
 from test import support
 
+import traceback
 import unittest
 
 
@@ -361,6 +362,15 @@ class Test_OldTestResult(unittest.TestCase):
         runner.run(Test('testFoo'))
 
 
+class MockTraceback(object):
+    @staticmethod
+    def format_exception(*_):
+        return ['A traceback']
+
+def restore_traceback():
+    unittest.result.traceback = traceback
+
+
 class TestOutputBuffering(unittest.TestCase):
 
     def setUp(self):
@@ -441,6 +451,9 @@ class TestOutputBuffering(unittest.TestCase):
         return result
 
     def testBufferOutputAddErrorOrFailure(self):
+        unittest.result.traceback = MockTraceback
+        self.addCleanup(restore_traceback)
+
         for message_attr, add_attr, include_error in [
             ('errors', 'addError', True),
             ('failures', 'addFailure', False),
@@ -476,7 +489,8 @@ class TestOutputBuffering(unittest.TestCase):
                 Stderr:
                 bar
             """)
-            expectedFullMessage = 'NoneType\n%s%s' % (expectedOutMessage, expectedErrMessage)
+
+            expectedFullMessage = 'A traceback%s%s' % (expectedOutMessage, expectedErrMessage)
 
             self.assertIs(test, self)
             self.assertEqual(result._original_stdout.getvalue(), expectedOutMessage)