MTB
if (!q || !mp || (mp->b_rptr - mp->b_datap->db_base) != sizeof (MTB))
if ((mp = allocb(size + sizeof (MTB), BPRI_HI)) != NULL) {
if (!mp || (mp->b_rptr - mp->b_datap->db_base) != sizeof (MTB))
if (!q || !mp || (mp->b_rptr - mp->b_datap->db_base) != sizeof (MTB))
if (!mp || (mp->b_rptr - mp->b_datap->db_base) != sizeof (MTB))
if (!mp || (mp->b_rptr - mp->b_datap->db_base) != sizeof (MTB) ||