contrib/revsetbenchmarks.txt

--- a/contrib/revsetbenchmarks.txt	Tue Sep 16 14:49:56 2014 -0500
+++ b/contrib/revsetbenchmarks.txt	Sun Sep 07 11:33:22 2014 -0700
@@ -23,6 +23,7 @@
 max(::(tip~20) - obsolete())
 roots((0:tip)::)
 (not public() - obsolete())
+roots((0::) - (0::tip))
 (_intlist('20000\x0020001')) and merge()
 parents(20000)
 (20000::) - (20000)