next_read_char
(void)next_read_char(0, (size_t)-1); /* attempt to seek back */
(void)next_read_char(0, 0); /* make sure the buffer is empty */
if ((c = next_read_char(0, maxlen + 1)) < 0) {
if ((c = next_read_char(0, maxlen + 1)) < 0) {