diff -r f39cf992216f -r d1aae6d4efc5 tests/test-command-template.t
--- a/tests/test-command-template.t	Sun Jan 07 15:56:58 2018 +0900
+++ b/tests/test-command-template.t	Sun Jan 07 12:07:29 2018 +0900
@@ -2218,6 +2218,11 @@
   $ cd ..
   $ rm -rf unstable-hash
 
+Filename filters:
+
+  $ hg debugtemplate '{"foo/bar"|basename}|{"foo/"|basename}|{"foo"|basename}|\n'
+  bar||foo|
+
 Add a dummy commit to make up for the instability of the above:
 
   $ echo a > a