ST_OP_NIL
optype new_lastop = ST_OP_NIL;
if (new_lastop != ST_OP_NIL) {
ASSERT(new_lastop != ST_OP_NIL);
un->un_lastop = ST_OP_NIL;
((flag == FWRITE) && (un->un_lastop == ST_OP_NIL)))) {
un->un_lastop = ST_OP_NIL;
un->un_lastop = ST_OP_NIL;