mercurial/revset.py

--- a/mercurial/revset.py	Tue Oct 07 01:36:53 2014 -0700
+++ b/mercurial/revset.py	Tue Oct 07 01:41:02 2014 -0700
@@ -664,7 +664,7 @@
 
     # Both sets need to be ascending in order to lazily return the union
     # in the correct order.
-    args.ascending()
+    args.sort()
     result = (filteredset(s, subset.__contains__, ascending=True) +
               filteredset(args, subset.__contains__, ascending=True))