I thought I had already fixed this error in the test.

Lib/test/test_codecs.py

@@ -916,7 +916,7 @@ class EncodedFileTest(unittest.TestCase):
     def test_basic(self):
         f = StringIO.StringIO('\xed\x95\x9c\n\xea\xb8\x80')
         ef = codecs.EncodedFile(f, 'utf-16-le', 'utf-8')
-        self.assertEquals(ef.read(), '\xff\xfe\\\xd5\n\x00\x00\xae')
+        self.assertEquals(ef.read(), '\\\xd5\n\x00\x00\xae')
 
         f = StringIO.StringIO()
         ef = codecs.EncodedFile(f, 'utf-8', 'latin1')