These test helper programs access the index, but do not ever
setup_git_directory(), meaning we just blindly looked in
".git/index". This happened to work for the purposes of our
tests (which do not run from subdirectories, nor in
non-repos), but it's a bad habit.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>