From 2dc90fdfaf79404ebbc91328af258b7895f86132 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <python@rcn.com>
Date: Wed, 25 Mar 2009 22:41:32 +0000
Subject: [PATCH] Separate initialization from clearing.

---
 Lib/collections.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Lib/collections.py b/Lib/collections.py
index da59608d3d4..d77aff5a238 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -41,14 +41,15 @@ class OrderedDict(dict, MutableMapping):
         try:
             self.__root
         except AttributeError:
-            self.__root = _Link()       # sentinel node for the doubly linked list
-            self.clear()
+            self.__root = root = _Link()    # sentinel node for the doubly linked list
+            root.prev = root.next = root
+            self.__map = {}
         self.update(*args, **kwds)
 
     def clear(self):
         root = self.__root
         root.prev = root.next = root
-        self.__map = {}
+        self.__map.clear()
         dict.clear(self)
 
     def __setitem__(self, key, value):