diff -r 35da5d848ffd Lib/test/test_sys.py
--- a/Lib/test/test_sys.py	Mon Sep 23 23:24:38 2013 +0300
+++ b/Lib/test/test_sys.py	Wed Sep 25 12:39:35 2013 +0300
@@ -525,60 +525,69 @@
     def test_clear_type_cache(self):
         sys._clear_type_cache()
 
+    def check_ioencoding(self, env, string, expected):
+        p = subprocess.Popen([sys.executable, "-c", 'print(%a)' % string],
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                             env=env)
+        out, err = p.communicate()
+        if expected is not None:
+            self.assertEqual(out.strip(), expected)
+        else:
+            self.assertEqual(out, b'')
+            self.assertIn(b'UnicodeEncodeError:', err)
+            self.assertIn(ascii(string).encode(), err)
+
     def test_ioencoding(self):
         env = dict(os.environ)
 
         # Test character: cent sign, encoded as 0x4A (ASCII J) in CP424,
         # not representable in ASCII.
-
         env["PYTHONIOENCODING"] = "cp424"
-        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
-                             stdout = subprocess.PIPE, env=env)
-        out = p.communicate()[0].strip()
-        expected = ("\xa2" + os.linesep).encode("cp424")
-        self.assertEqual(out, expected)
+        self.check_ioencoding(env, '\xa2', ("\xa2" + os.linesep).encode("cp424"))
 
         env["PYTHONIOENCODING"] = "ascii:replace"
-        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
-                             stdout = subprocess.PIPE, env=env)
-        out = p.communicate()[0].strip()
-        self.assertEqual(out, b'?')
+        self.check_ioencoding(env, '\xa2', b'?')
 
         env["PYTHONIOENCODING"] = "ascii"
-        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
-                             stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                             env=env)
-        out, err = p.communicate()
-        self.assertEqual(out, b'')
-        self.assertIn(b'UnicodeEncodeError:', err)
-        self.assertIn(rb"'\xa2'", err)
+        self.check_ioencoding(env, '\xa2', None)
 
         env["PYTHONIOENCODING"] = "ascii:"
-        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
-                             stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                             env=env)
-        out, err = p.communicate()
-        self.assertEqual(out, b'')
-        self.assertIn(b'UnicodeEncodeError:', err)
-        self.assertIn(rb"'\xa2'", err)
+        self.check_ioencoding(env, '\xa2', None)
 
         env["PYTHONIOENCODING"] = ":surrogateescape"
-        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xdcbd))'],
-                             stdout=subprocess.PIPE, env=env)
-        out = p.communicate()[0].strip()
-        self.assertEqual(out, b'\xbd')
+        self.check_ioencoding(env, '\udcbd', b'\xbd')
 
-    @unittest.skipUnless(test.support.FS_NONASCII,
-                         'requires OS support of non-ASCII encodings')
-    def test_ioencoding_nonascii(self):
+    def test_ioencoding_locale(self):
+        encodable = unencodable = None
+        import locale
+        encoding = locale.getpreferredencoding()
+        if encoding:
+            for c in '\xe6\u0130\u0141\u03c6\u041a\u05d0'\
+                     '\u060c\u062a\u0e01\xa0\u20ac\udcbd':
+                try:
+                    if c.encode(encoding).strip():
+                        encodable = c
+                except UnicodeEncodeError:
+                    unencodable = c
+                if encodable and unencodable:
+                    break
+        if not encodable:
+            raise unittest.SkipTest('requires non-ASCII locale')
+
         env = dict(os.environ)
 
         env["PYTHONIOENCODING"] = ""
-        p = subprocess.Popen([sys.executable, "-c",
-                                'print(%a)' % test.support.FS_NONASCII],
-                                stdout=subprocess.PIPE, env=env)
-        out = p.communicate()[0].strip()
-        self.assertEqual(out, os.fsencode(test.support.FS_NONASCII))
+        self.check_ioencoding(env, encodable, encodable.encode(encoding).strip())
+        if unencodable:
+            self.check_ioencoding(env, unencodable, None)
+
+        del env["PYTHONIOENCODING"]
+        self.check_ioencoding(env, encodable, encodable.encode(encoding).strip())
+        if unencodable:
+            self.check_ioencoding(env, unencodable, None)
+
+
+
 
     @unittest.skipIf(sys.base_prefix != sys.prefix,
                      'Test is not venv-compatible')