mempacket_move_packet
if (!TEST_true(mempacket_move_packet(bio, 0, 1)))
if (!TEST_true(mempacket_move_packet(bio, 0, 2)))
if (!TEST_true(mempacket_move_packet(bio, 1, 2)))
if (!TEST_true(mempacket_move_packet(bio, 0, 2)))
int mempacket_move_packet(BIO *bio, int d, int s);