--- a/mercurial/changelog.py	Tue May 08 23:59:39 2012 +0400
+++ b/mercurial/changelog.py	Fri May 11 01:55:33 2012 -0700
@@ -153,6 +153,7 @@
         r = revlog.revlog(self.opener, file)
         self.index = r.index
         self.nodemap = r.nodemap
+        self._nodecache = r._nodecache
         self._chunkcache = r._chunkcache
 
     def writepending(self):