SBUF_FREESPACE
if (SBUF_FREESPACE(s) <= 0) {
n = SBUF_FREESPACE(s);
if (len > SBUF_FREESPACE(s)) {
sbuf_extend(s, len - SBUF_FREESPACE(s));
if (SBUF_FREESPACE(s) < len)
len = SBUF_FREESPACE(s);
len = SBUF_FREESPACE(s); /* XXX return 0? */
if (len > SBUF_FREESPACE(s)) {
if (SBUF_FREESPACE(s) < len)
len = SBUF_FREESPACE(s);
len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
if (SBUF_FREESPACE(s) >= len)
error = sbuf_extend(s, len - SBUF_FREESPACE(s));
if (SBUF_FREESPACE(s) < len)
len = SBUF_FREESPACE(s);