diff -r e17976978ee4 -r 6031fe568cd0 mercurial/revlog.py
--- a/mercurial/revlog.py	Fri Sep 06 23:05:11 2013 -0700
+++ b/mercurial/revlog.py	Fri Sep 06 23:05:33 2013 -0700
@@ -883,9 +883,6 @@
 
         return l
 
-    def _chunkbase(self, rev):
-        return self._chunk(rev)
-
     def _chunkclear(self):
         self._chunkcache = (0, '')