--- a/tests/test-commit.t	Thu Jul 27 12:03:01 2017 -0700
+++ b/tests/test-commit.t	Fri Jul 28 07:42:55 2017 +0530
@@ -135,6 +135,9 @@
   $ hg commit -m "adding internal used extras" --extra amend_source=hash
   abort: key 'amend_source' is used internally, can't be set manually
   [255]
+  $ hg commit -m "special chars in extra" --extra id@phab=214
+  abort: keys can only contain ascii letters, digits, '_' and '-'
+  [255]
   $ hg commit -m "adding extras" --extra sourcehash=foo --extra oldhash=bar
   $ hg log -r . -T '{extras % "{extra}\n"}'
   branch=default