diff -r 4b9e5b71dfa9 -r 3bfd7f1e7485 mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Thu May 16 16:20:10 2013 -0500
+++ b/mercurial/cmdutil.py	Tue May 14 11:23:15 2013 -0700
@@ -2082,3 +2082,6 @@
         return decorator
 
     return cmd
+
+# a list of (ui, repo) functions called by commands.summary
+summaryhooks = util.hooks()