diff -r 012be286b2c4 -r c5f36402daad mercurial/changelog.py
--- a/mercurial/changelog.py	Wed Jun 10 03:20:20 2009 +0200
+++ b/mercurial/changelog.py	Wed Jun 10 15:10:21 2009 +0200
@@ -36,7 +36,7 @@
     items = [_string_escape('%s:%s' % (k, d[k])) for k in sorted(d)]
     return "\0".join(items)
 
-class appender:
+class appender(object):
     '''the changelog index must be updated last on disk, so we use this class
     to delay writes to it'''
     def __init__(self, fp, buf):