sequencer: convert do_recursive_merge to struct object_id

This conversion is required to convert parse_tree_indirect.

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

sequencer.c

@@ -426,7 +426,7 @@ void append_conflicts_hint(struct strbuf *msgbuf)
 
 static int do_recursive_merge(struct commit *base, struct commit *next,
 			      const char *base_label, const char *next_label,
-			      unsigned char *head, struct strbuf *msgbuf,
+			      struct object_id *head, struct strbuf *msgbuf,
 			      struct replay_opts *opts)
 {
 	struct merge_options o;
@@ -446,7 +446,7 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
 	if (is_rebase_i(opts))
 		o.buffer_output = 2;
 
-	head_tree = parse_tree_indirect(head);
+	head_tree = parse_tree_indirect(head->hash);
 	next_tree = next ? next->tree : empty_tree();
 	base_tree = base ? base->tree : empty_tree();
 
@@ -1081,7 +1081,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 		res = -1;
 	else if (!opts->strategy || !strcmp(opts->strategy, "recursive") || command == TODO_REVERT) {
 		res = do_recursive_merge(base, next, base_label, next_label,
-					 head.hash, &msgbuf, opts);
+					 &head, &msgbuf, opts);
 		if (res < 0)
 			return res;
 		res |= write_message(msgbuf.buf, msgbuf.len,