diff -r 4e33c343a264 Lib/test/test_ntpath.py
--- a/Lib/test/test_ntpath.py	Mon May 12 20:36:46 2014 +0200
+++ b/Lib/test/test_ntpath.py	Tue May 13 13:06:50 2014 +0300
@@ -341,6 +341,42 @@
             self.assertTrue(ntpath.ismount(b"\\\\localhost\\c$"))
             self.assertTrue(ntpath.ismount(b"\\\\localhost\\c$\\"))
 
+    def test_expanduser(self):
+        self.assertEqual(ntpath.expanduser('test'), 'test')
+        self.assertEqual(ntpath.expanduser(b'test'), b'test')
+
+        with support.EnvironmentVarGuard() as env:
+            env.clear()
+            self.assertEqual(ntpath.expanduser('~test'), '~test')
+
+            env['HOMEPATH'] = 'eric\\idle'
+            env['HOMEDRIVE'] = 'C:\\'
+            self.assertEqual(ntpath.expanduser('~test'), 'C:\\eric\\test')
+            self.assertEqual(ntpath.expanduser('~'), 'C:\\eric\\idle')
+            self.assertEqual(ntpath.expanduser(b'~test'), b'C:\\eric\\test')
+            self.assertEqual(ntpath.expanduser(b'~'), b'C:\\eric\\idle')
+
+            del env['HOMEDRIVE']
+            self.assertEqual(ntpath.expanduser('~test'), 'eric\\test')
+            self.assertEqual(ntpath.expanduser('~'), 'eric\\idle')
+            self.assertEqual(ntpath.expanduser(b'~test'), b'eric\\test')
+            self.assertEqual(ntpath.expanduser(b'~'), b'eric\\idle')
+
+            env.clear()
+            env['USERPROFILE'] = 'C:\\eric\\idle'
+            self.assertEqual(ntpath.expanduser('~test'), 'C:\\eric\\test')
+            self.assertEqual(ntpath.expanduser('~'), 'C:\\eric\\idle')
+            self.assertEqual(ntpath.expanduser(b'~test'), b'C:\\eric\\test')
+            self.assertEqual(ntpath.expanduser(b'~'), b'C:\\eric\\idle')
+
+            env.clear()
+            env['HOME'] = 'C:\\idle\\eric'
+            self.assertEqual(ntpath.expanduser('~test'), 'C:\\idle\\test')
+            self.assertEqual(ntpath.expanduser('~'), 'C:\\idle\\eric')
+            self.assertEqual(ntpath.expanduser(b'~test'), b'C:\\idle\\test')
+            self.assertEqual(ntpath.expanduser(b'~'), b'C:\\idle\\eric')
+
+
 class NtCommonTest(test_genericpath.CommonTest, unittest.TestCase):
     pathmodule = ntpath
     attributes = ['relpath', 'splitunc']