--- a/mercurial/util.py	Sun Jul 22 13:16:45 2012 +0200
+++ b/mercurial/util.py	Mon Jul 23 15:38:43 2012 -0700
@@ -816,6 +816,8 @@
 
         # delegated methods
         self.write = self._fp.write
+        self.seek = self._fp.seek
+        self.tell = self._fp.tell
         self.fileno = self._fp.fileno
 
     def close(self):