On a case insensitive file system, this test fails because git-diff
doesn't know if it is asking for the file "A" or the tag "a".
Adding "--" at the end of the ambiguous commands allows the test to
finish properly.
Signed-off-by: Brian Gernhardt <benji@silverinsanity.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
