--- a/tests/test-topic-stack.t	Mon Mar 14 23:37:58 2016 +0000
+++ b/tests/test-topic-stack.t	Thu Mar 17 09:13:12 2016 -0700
@@ -111,6 +111,14 @@
   t2$ c_e (unstable)
   t3$ c_f (unstable)
 
+Also test the revset:
+
+  $ hg log -r 'stack()'
+  2 default {foo} draft c_c
+  7 default {foo} draft c_d
+  4 default {foo} draft c_e
+  5 default {foo} draft c_f
+
 Case with multiple heads on the topic
 -------------------------------------