--- a/tests/test-topic-stack.t	Fri Sep 01 19:29:04 2017 +0200
+++ b/tests/test-topic-stack.t	Thu Sep 07 16:45:53 2017 +0200
@@ -58,6 +58,16 @@
   t2@ c_b (current)
   t1: c_a
   $ hg phase --public 'topic("other")'
+
+After changing the phase of all the changesets in "other" to public, the topic should still be active, but is empty. We should be better at informating the user about it and displaying good data in this case.
+
+  $ hg topic
+     foo
+   * other
+  $ hg stack
+  ### topic: other
+  ### branch: 
+
   $ hg up foo
   switching to topic foo
   4 files updated, 0 files merged, 0 files removed, 0 files unresolved