Function test_zero

test/file-register.c:398–432

* Register 0 files, but reserve space for 10. Then add one file. */

 * Register 0 files, but reserve space for 10.  Then add one file.
 */
static int test_zero(struct io_uring *ring)
{
	int *files, *fds = NULL;
	int ret;

	files = open_files(0, 10, 0);
	ret = io_uring_register_files(ring, files, 10);
	if (ret) {
		fprintf(stderr, "%s: register ret=%d\n", __FUNCTION__, ret);
		goto err;
	}

	fds = open_files(1, 0, 1);
	ret = io_uring_register_files_update(ring, 0, fds, 1);
	if (ret != 1) {
		fprintf(stderr, "%s: update ret=%d\n", __FUNCTION__, ret);
		goto err;
	}

	ret = io_uring_unregister_files(ring);
	if (ret) {
		fprintf(stderr, "%s: unregister ret=%d\n", __FUNCTION__, ret);
		goto err;
	}

	if (fds)
		close_files(fds, 1, 1);
	free(files);
	return 0;
err:
	if (fds)
		close_files(fds, 1, 1);
	free(files);
	return 1;
}

static int test_fixed_read_write(struct io_uring *ring, int index)
{