git-p4: add failing test for submit from detached head
git-p4: add failing test for submit from detached head

git-p4 can't submit from a detached head. This test case
demonstrates the problem.

Signed-off-by: Luke Diamand <6b3799be4300e44489a08090123f3842e6419da5@diamand.org>
Signed-off-by: Jeff King <696e3fbcf235d40b6ea1ebd61c87cbea79d444e7@peff.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git