diff -r 848c428bb5ee -r 98c867ac1330 mercurial/util.py
--- a/mercurial/util.py	Mon Oct 08 18:11:56 2012 +0200
+++ b/mercurial/util.py	Mon Oct 08 20:02:20 2012 +0200
@@ -244,9 +244,12 @@
         self.name = func.__name__
     def __get__(self, obj, type=None):
         result = self.func(obj)
-        setattr(obj, self.name, result)
+        self.cachevalue(obj, result)
         return result
 
+    def cachevalue(self, obj, value):
+        setattr(obj, self.name, value)
+
 def pipefilter(s, cmd):
     '''filter string S through command CMD, returning its output'''
     p = subprocess.Popen(cmd, shell=True, close_fds=closefds,