Enhance git-ls-tree to allow optional 'match paths' that
restricts the output of git-ls-tree. This is useful to retrieve
a single file's SHA1 out of a tree without creating an index.
[JC: I added the test case]
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>