diff -r 21b3513d43e4 -r 667df8f478d1 mercurial/changelog.py
--- a/mercurial/changelog.py	Thu May 22 22:05:26 2014 +0900
+++ b/mercurial/changelog.py	Tue May 20 13:55:08 2014 -0700
@@ -127,6 +127,7 @@
             self._generaldelta = False
         self._realopener = opener
         self._delayed = False
+        self._delaybuf = []
         self._divert = False
         self.filteredrevs = frozenset()