In commit ad3f9a7 (Add '--bisect' revision machinery argument) the
'--bisect' option was added to easily pass bisection refs to
commands using the revision machinery.
So it is now shorter and safer to use the new '--bisect' revision
machinery option, than to compute the refs that we must pass.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>