--- a/tests/test-revset.t	Sat May 28 12:29:59 2016 -0700
+++ b/tests/test-revset.t	Sat May 14 19:46:18 2016 +0900
@@ -962,6 +962,12 @@
   6
   2
 
+test invalid sort keys
+
+  $ log 'sort(all(), -invalid)'
+  hg: parse error: unknown sort key '-invalid'
+  [255]
+
   $ cd ..
 
 test sorting by multiple keys including variable-length strings