Function refs_update_symref_extended

refs.c:2504–2553

}

int refs_update_symref_extended(struct ref_store *refs, const char *ref,
		       const char *target, const char *logmsg,
		       struct strbuf *referent, int create_only)
{
	struct ref_transaction *transaction;
	struct strbuf err = STRBUF_INIT;
	int ret = 0, prepret = 0;

	transaction = ref_store_transaction_begin(refs, 0, &err);
	if (!transaction) {
	error_return:
		ret = error("%s", err.buf);
		goto cleanup;
	}
	if (create_only) {
		if (ref_transaction_create(transaction, ref, NULL, target,
					   REF_NO_DEREF, logmsg, &err))
			goto error_return;
		prepret = ref_transaction_prepare(transaction, &err);
		if (prepret && prepret != REF_TRANSACTION_ERROR_CREATE_EXISTS)
			goto error_return;
	} else {
		if (ref_transaction_update(transaction, ref, NULL, NULL,
					   target, NULL, REF_NO_DEREF,
					   logmsg, &err) ||
			ref_transaction_prepare(transaction, &err))
			goto error_return;
	}

	if (referent && refs_read_symbolic_ref(refs, ref, referent) == NOT_A_SYMREF) {
		struct object_id oid;
		if (!refs_read_ref(refs, ref, &oid)) {
			strbuf_add_oid_hex(referent, &oid);
			ret = NOT_A_SYMREF;
		}
	}

	if (prepret == REF_TRANSACTION_ERROR_CREATE_EXISTS)
		goto cleanup;

	if (ref_transaction_commit(transaction, &err))
		goto error_return;

cleanup:
	strbuf_release(&err);
	if (transaction)
		ref_transaction_free(transaction);

	return ret;
}

/*
 * Write an error to `err` and return a nonzero value iff the same