[PATCH] Flag empty patches as errors

[PATCH] Flag empty patches as errors

A patch that contains no actual diff, and that doesn't change any
meta-data is bad. It shouldn't be a patch at all, and git-apply shouldn't
just accept it.

This caused a corrupted patch to be silently applied as an empty change in
the kernel, because the corruption ended up making the patch look empty.

An example of such a patch is one that contains the patch header, but
where the initial fragment header (the "@@ -nr,.." line) is missing,
causing us to not parse any fragments.

The real "patch" program will also flag such patches as bad, with the
message

	patch: **** Only garbage was found in the patch input.

and we should do likewise.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>