--- a/tests/test-command-template.t	Wed Mar 11 15:22:34 2015 -0700
+++ b/tests/test-command-template.t	Tue Feb 24 00:04:55 2015 +0900
@@ -1901,6 +1901,11 @@
   hg: parse error: unknown function 'foo'
   [255]
 
+Pass generator object created by template function to filter
+
+  $ hg log -l 1 --template '{if(author, author)|user}\n'
+  test
+
 Test diff function:
 
   $ hg diff -c 8