diff: convert diff_flush_patch_id to struct object_id

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -4584,7 +4584,7 @@ static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
 }
 
 /* returns 0 upon success, and writes result into sha1 */
-static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
+static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
@@ -4656,9 +4656,9 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
 		if (diff_filespec_is_binary(p->one) ||
 		    diff_filespec_is_binary(p->two)) {
 			git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
-					40);
+					GIT_SHA1_HEXSZ);
 			git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
-					40);
+					GIT_SHA1_HEXSZ);
 			continue;
 		}
 
@@ -4671,15 +4671,15 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
 				     p->one->path);
 	}
 
-	git_SHA1_Final(sha1, &ctx);
+	git_SHA1_Final(oid->hash, &ctx);
 	return 0;
 }
 
-int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
+int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
-	int result = diff_get_patch_id(options, sha1, diff_header_only);
+	int result = diff_get_patch_id(options, oid, diff_header_only);
 
 	for (i = 0; i < q->nr; i++)
 		diff_free_filepair(q->queue[i]);

diff.h

@@ -354,7 +354,7 @@ extern int run_diff_files(struct rev_info *revs, unsigned int option);
 extern int run_diff_index(struct rev_info *revs, int cached);
 
 extern int do_diff_cache(const struct object_id *, struct diff_options *);
-extern int diff_flush_patch_id(struct diff_options *, unsigned char *, int);
+extern int diff_flush_patch_id(struct diff_options *, struct object_id *, int);
 
 extern int diff_result_code(struct diff_options *, int);
 

patch-ids.c

@@ -22,7 +22,7 @@ int commit_patch_id(struct commit *commit, struct diff_options *options,
 	else
 		diff_root_tree_sha1(commit->object.oid.hash, "", options);
 	diffcore_std(options);
-	return diff_flush_patch_id(options, oid->hash, diff_header_only);
+	return diff_flush_patch_id(options, oid, diff_header_only);
 }
 
 /*