diff -r eccf9907b844 -r 3ed3ca4dfd31 mercurial/revset.py
--- a/mercurial/revset.py	Fri Oct 03 00:12:22 2014 -0500
+++ b/mercurial/revset.py	Thu Oct 02 19:42:06 2014 -0500
@@ -2554,7 +2554,7 @@
         self._subset.reverse()
         self._ascending = not self._ascending
 
-class _addset(_orderedsetmixin):
+class _addset(abstractsmartset):
     """Represent the addition of two sets
 
     Wrapper structure for lazily adding two structures without losing much