Use find() instead of looping over the string in expanduser().
From SF patch #757058.
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index 9ba7216..30551d8 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -332,12 +332,16 @@
 
     def test_expanduser(self):
         self.assertEqual(posixpath.expanduser("foo"), "foo")
-        self.assert_(isinstance(posixpath.expanduser("~/"), basestring))
         try:
             import pwd
         except ImportError:
             pass
         else:
+            self.assert_(isinstance(posixpath.expanduser("~/"), basestring))
+            self.assertEqual(
+                posixpath.expanduser("~") + "/",
+                posixpath.expanduser("~/")
+            )
             self.assert_(isinstance(posixpath.expanduser("~root/"), basestring))
             self.assert_(isinstance(posixpath.expanduser("~foo/"), basestring))