--- a/tests/test-revset.t	Mon May 01 05:57:36 2017 +0200
+++ b/tests/test-revset.t	Sun Jun 18 12:25:23 2017 +0900
@@ -3131,9 +3131,11 @@
   $ log 'merge()^^^'
   1
 
-  $ log '(merge() | 0)~-1'
+  $ hg debugrevspec -s '(merge() | 0)~-1'
+  * set:
+  <baseset+ [1, 7]>
+  1
   7
-  1
   $ log 'merge()~-1'
   7
   $ log 'tip~-1'