--- a/tests/test-topic.t	Thu Jan 10 17:30:01 2019 +0100
+++ b/tests/test-topic.t	Wed Dec 26 14:52:07 2018 +0800
@@ -823,8 +823,8 @@
 
   $ cd ..
 
-Stack relation subscript in revsets
-===================================
+Relation subscript in revsets
+=============================
 
   $ hg init more-than-one-commit-per-topic
   $ cd more-than-one-commit-per-topic
@@ -854,6 +854,24 @@
   3: featureA
   4: 
 
+topic subscript relation
+
+  $ tlog 'featureA'
+  3: featureA
+  $ tlog 'featureA#topic[0]'
+  3: featureA
+
+  $ tlog '2#t[-2]'
+  $ tlog '2#t[-1]'
+  1: featureA
+  $ tlog '2#t[0]'
+  2: featureA
+  $ tlog '2#t[1]'
+  3: featureA
+  $ tlog '2#t[2]'
+
+stack subscript relation
+
   $ hg stack
   ### target: default (branch)
   s2@ 4 (current)