This patch extends diff-cache and diff-files to report the
unmodified files to diff-core as well when -C (copy detection)
is in effect, so that the unmodified files can also be used as
the source candidates. The existing test t4003 has been
extended to cover this case.
Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>