replace_object: convert struct replace_object to object_id

Convert the two members of this struct to be instances of struct
object_id.  Adjust the various functions in this file accordingly.

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

replace_object.c

@@ -8,8 +8,8 @@
  * sha1.
  */
 static struct replace_object {
-	unsigned char original[20];
-	unsigned char replacement[20];
+	struct object_id original;
+	struct object_id replacement;
 } **replace_object;
 
 static int replace_object_alloc, replace_object_nr;
@@ -17,7 +17,7 @@ static int replace_object_alloc, replace_object_nr;
 static const unsigned char *replace_sha1_access(size_t index, void *table)
 {
 	struct replace_object **replace = table;
-	return replace[index]->original;
+	return replace[index]->original.hash;
 }
 
 static int replace_object_pos(const unsigned char *sha1)
@@ -29,7 +29,7 @@ static int replace_object_pos(const unsigned char *sha1)
 static int register_replace_object(struct replace_object *replace,
 				   int ignore_dups)
 {
-	int pos = replace_object_pos(replace->original);
+	int pos = replace_object_pos(replace->original.hash);
 
 	if (0 <= pos) {
 		if (ignore_dups)
@@ -59,14 +59,14 @@ static int register_replace_ref(const char *refname,
 	const char *hash = slash ? slash + 1 : refname;
 	struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
 
-	if (strlen(hash) != 40 || get_sha1_hex(hash, repl_obj->original)) {
+	if (get_oid_hex(hash, &repl_obj->original)) {
 		free(repl_obj);
 		warning("bad replace ref name: %s", refname);
 		return 0;
 	}
 
 	/* Copy sha1 from the read ref */
-	hashcpy(repl_obj->replacement, oid->hash);
+	oidcpy(&repl_obj->replacement, oid);
 
 	/* Register new object */
 	if (register_replace_object(repl_obj, 1))
@@ -113,7 +113,7 @@ const unsigned char *do_lookup_replace_object(const unsigned char *sha1)
 
 		pos = replace_object_pos(cur);
 		if (0 <= pos)
-			cur = replace_object[pos]->replacement;
+			cur = replace_object[pos]->replacement.hash;
 	} while (0 <= pos);
 
 	return cur;