lines may pass through operation/subroutine blocks

hi,

I used flowchart in stackedit, I found below input could generate some
lines pass through operation/subroutines, any solution to solve it?

enter=>start: Start
return=>end: End
is_lastpkt=>condition: Is it last packet?
is_fastpath=>condition: Should it enter fastpath？
is_arp=>condition: is it a ARP packet?
prepare_one=>subroutine: prepare to receive it
process_arp=>operation: handle ARP
drop=>operation: drop it!
push_them_to_user=>subroutine: call user callback

enter->is_lastpkt
is_lastpkt(yes)->push_them_to_user->return
is_lastpkt(no,bottom)->is_fastpath
is_fastpath(yes)->prepare_one->is_lastpkt
prepare_one->drop
is_fastpath(no,bottom)->is_arp
is_arp(no,bottom)->drop->is_lastpkt
is_arp(yes)->process_arp->is_lastpkt

Thanks

Yu