Correct implementation and documentation of os.confstr. Add a simple test

case.  I've yet to figure out how to provoke a None return I can test.

1 files changed, 5 insertions, 0 deletions

diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index 1ccc62bdf2..f98c723193 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -73,6 +73,11 @@ class PosixTester(unittest.TestCase):
             finally:
                 fp.close()
 
+    def test_confstr(self):
+        if hasattr(posix, 'confstr'):
+            self.assertRaises(ValueError, posix.confstr, "CS_garbage")
+            self.assertEqual(len(posix.confstr("CS_PATH")) > 0, True)
+
     def test_dup2(self):
         if hasattr(posix, 'dup2'):
             fp1 = open(test_support.TESTFN)