RE: [lwip-users] Strange "always true" conditional in tcp_in.c

[Bill Auerbach]

The macro below would be computed at compile time - there is no overhead in
this implementation which is why I thought it to be better than the previous
suggestion which used a variable.

It could be more generic: #define max_unsigned since it can be used in all
unsigned overflow checks.

Bill

>#define max_dup_acks(size) (size == 1 ? 0xffu : size == 2 ? 0xffffu :
>0xfffffffful)
>
>if (pcb->dupacks != max_dup_acks(sizeof pcb->dupacks))
>  ++pcb->dupacks;