Merge branch 'jc/test-must-be-empty'

Test helper update. * jc/test-must-be-empty: test_must_be_empty: simplify file existence check

Junio C Hamano committed Apr 11, 2018 at 13:09 UTC 5ff42d42da9c2c26737988d19b347c99489c8faa

No changes.