coccinelle: convert hashcpy() with null_sha1 to hashclr()

hashcpy with null_sha1 as the source is equivalent to hashclr.  In
addition to being simpler, using hashclr may give the compiler a chance
to optimize better.  Convert instances of hashcpy with the source
argument of null_sha1 to hashclr.

This transformation was implemented using the following semantic patch:

@@
expression E1;
@@
-hashcpy(E1, null_sha1);
+hashclr(E1);

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/diff.c b/diff.c
index fa78fc189c..f2234012fa 100644
--- a/diff.c
+++ b/diff.c
@@ -3134,7 +3134,7 @@ static void diff_fill_sha1_info(struct diff_filespec *one)
 		if (!one->sha1_valid) {
 			struct stat st;
 			if (one->is_stdin) {
-				hashcpy(one->sha1, null_sha1);
+				hashclr(one->sha1);
 				return;
 			}
 			if (lstat(one->path, &st) < 0)