builtin/unpack-file: convert to struct object_id

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

builtin/unpack-file.c

@@ -1,7 +1,7 @@
 #include "builtin.h"
 #include "config.h"
 
-static char *create_temp_file(unsigned char *sha1)
+static char *create_temp_file(struct object_id *oid)
 {
 	static char path[50];
 	void *buf;
@@ -9,9 +9,9 @@ static char *create_temp_file(unsigned char *sha1)
 	unsigned long size;
 	int fd;
 
-	buf = read_sha1_file(sha1, &type, &size);
+	buf = read_sha1_file(oid->hash, &type, &size);
 	if (!buf || type != OBJ_BLOB)
-		die("unable to read blob object %s", sha1_to_hex(sha1));
+		die("unable to read blob object %s", oid_to_hex(oid));
 
 	xsnprintf(path, sizeof(path), ".merge_file_XXXXXX");
 	fd = xmkstemp(path);
@@ -23,15 +23,15 @@ static char *create_temp_file(unsigned char *sha1)
 
 int cmd_unpack_file(int argc, const char **argv, const char *prefix)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	if (argc != 2 || !strcmp(argv[1], "-h"))
 		usage("git unpack-file <sha1>");
-	if (get_sha1(argv[1], sha1))
+	if (get_oid(argv[1], &oid))
 		die("Not a valid object name %s", argv[1]);
 
 	git_config(git_default_config, NULL);
 
-	puts(create_temp_file(sha1));
+	puts(create_temp_file(&oid));
 	return 0;
 }