Index: Lib/test/test_pep277.py
===================================================================
--- Lib/test/test_pep277.py	(revision 79135)
+++ Lib/test/test_pep277.py	(working copy)
@@ -1,6 +1,7 @@
 # Test the Unicode versions of normal file functions
 # open, os.open, os.stat. os.listdir, os.rename, os.remove, os.mkdir, os.chdir, os.rmdir
 import sys, os, unittest
+from unicodedata import normalize
 from test import test_support
 
 filenames = [
@@ -13,8 +14,22 @@
     u'\u05d4\u05e9\u05e7\u05e6\u05e5\u05e1',
     u'\u66e8\u66e9\u66eb',
     u'\u66e8\u05e9\u3093\u0434\u0393\xdf',
+    # Specific code points: fn, NFC(fn) and NFKC(fn) all differents
+    u'\u2000\u2000\u2000',
+    u'\u2001\u2001\u2001',
+    u'\u2002\u2002\u2002',  # == NFC(u'\u2000\u2000\u2000')
+    u'\u2003\u2003\u2003',  # == NFC(u'\u2001\u2001\u2001')
+    u'   ',                 # u' ' == NFKC(u'\u2000') == NFKC(u'\u2001')
+                            #      == NFKC(u'\u2002') == NFKC(u'\u2003')
+    u'\u1fee\u1ffd\ufad1',
+    # Specific code points: NFC(fn), NFD(fn), NFKC(fn) and NFKD(fn) all differents
+    u'\u0385\u03d3\u03d4',
+    u'\u00a8\u0301\u03d2\u0301\u03d2\u0308',    # == NFD(u'\u0385\u03d3\u03d4')
+    u'\u0020\u0308\u0301\u038e\u03ab',          # == NFKC(u'\u0385\u03d3\u03d4')
+    u'\u1e9b\u1fc1\u1fcd\u1fce\u1fcf\u1fdd\u1fde\u1fdf\u1fed',
     ]
 
+
 # Destroy directory dirname and all files under it, to one level.
 def deltree(dirname):
     # Don't hide legitimate errors:  if one of these suckers exists, it's
@@ -25,15 +40,19 @@
             os.unlink(os.path.join(dirname, fname))
         os.rmdir(dirname)
 
+
 class UnicodeFileTests(unittest.TestCase):
-    files = [os.path.join(test_support.TESTFN, f) for f in filenames]
+    files = set(filenames)
+    normal_form = None
 
     def setUp(self):
         try:
             os.mkdir(test_support.TESTFN)
         except OSError:
             pass
+        files = set()
         for name in self.files:
+            name = os.path.join(test_support.TESTFN, self.norm(name))
             try:
                 f = open(name, 'w')
             except UnicodeEncodeError:
@@ -43,10 +62,17 @@
             f.write((name+'\n').encode("utf-8"))
             f.close()
             os.stat(name)
+            files.add(name)
+        self.files = files
 
     def tearDown(self):
         deltree(test_support.TESTFN)
 
+    def norm(self, s):
+        if self.normal_form and isinstance(s, unicode):
+            return normalize(self.normal_form, s)
+        return s
+
     def _apply_failure(self, fn, filename, expected_exception,
                        check_fn_in_exception = True):
         try:
@@ -82,14 +108,42 @@
             f.close()
             os.stat(name)
 
+    def test_normalize(self):
+        files = set(f for f in self.files if isinstance(f, unicode))
+        others = set()
+        for nf in set(['NFC', 'NFD', 'NFKC', 'NFKD']):
+            others |= set(normalize(nf, file) for file in files)
+        others -= files
+        if sys.platform == 'darwin':
+            files = set(normalize('NFC', file) for file in files)
+        for name in others:
+            if sys.platform == 'darwin' and normalize('NFC', name) in files:
+                os.stat(name)
+                continue
+            self._apply_failure(open, name, IOError)
+            self._apply_failure(os.stat, name, OSError)
+            self._apply_failure(os.chdir, name, OSError)
+            self._apply_failure(os.rmdir, name, OSError)
+            self._apply_failure(os.remove, name, OSError)
+            # listdir may append a wildcard to the filename, so dont check
+            self._apply_failure(os.listdir, name, OSError, False)
+
     def test_listdir(self):
         f1 = os.listdir(test_support.TESTFN)
         f2 = os.listdir(unicode(test_support.TESTFN,
                                 sys.getfilesystemencoding()))
-        sf2 = set(os.path.join(unicode(test_support.TESTFN), f)
-                  for f in f2)
+        if sys.platform == 'darwin' and self.normal_form not in ('NFD', 'NFKD'):
+            # Mac OS X returns canonically decomposed Unicode (Normal Form D)
+            # http://developer.apple.com/mac/library/qa/qa2001/qa1173.html
+            f2 = (normalize('NFC', unicode(f)) for f in f2)
+        if sys.platform == 'darwin' and self.normal_form is None:
+            # Some filenames have NFC(name) != name
+            sf0 = set(normalize('NFC', unicode(f)) for f in self.files)
+        else:
+            sf0 = set(self.files)
+        sf2 = set(os.path.join(unicode(test_support.TESTFN), f) for f in f2)
         self.assertEqual(len(f1), len(self.files))
-        self.assertEqual(sf2, set(self.files))
+        self.assertEqual(sf2, sf0)
 
     def test_rename(self):
         for name in self.files:
@@ -110,11 +164,35 @@
         os.chdir(oldwd)
         os.rmdir(dirname)
 
+
+class UnicodeNFCFileTests(UnicodeFileTests):
+    normal_form = 'NFC'
+
+
+class UnicodeNFDFileTests(UnicodeFileTests):
+    normal_form = 'NFD'
+
+
+class UnicodeNFKCFileTests(UnicodeFileTests):
+    normal_form = 'NFKC'
+
+
+class UnicodeNFKDFileTests(UnicodeFileTests):
+    normal_form = 'NFKD'
+
+
 def test_main():
     try:
-        test_support.run_unittest(UnicodeFileTests)
+        test_support.run_unittest(
+            UnicodeFileTests,
+            UnicodeNFCFileTests,
+            UnicodeNFDFileTests,
+            UnicodeNFKCFileTests,
+            UnicodeNFKDFileTests,
+        )
     finally:
         deltree(test_support.TESTFN)
 
+
 if __name__ == "__main__":
     test_main()