in src/transport/xqc_send_queue.c [590:597]
void xqc_send_queue_drop_handshake_packets(xqc_connection_t *conn)
{
/* handshake packets are send on conn_initial_path */
xqc_send_ctl_t *send_ctl = conn->conn_initial_path->path_send_ctl;
xqc_send_queue_t *send_queue = conn->conn_send_queue;
xqc_send_queue_drop_packets_with_type(send_ctl, send_queue, XQC_PTYPE_HSK);
xqc_send_ctl_on_pns_discard(send_ctl, XQC_PNS_HSK);
}