[lwip-users] upgrade to 0.6.2

[Ed Sutter]

Hello,
Until today I had been working with a version of LWIP that I got from CVS around
the end of January 2003.  My system was working well, however, based on the
improvements made since then, I decided to upgrade to 0.6.2.
I made the following changes and now I "almost" have it working...

In sys_arch.c... 
  sys_arch_mbox_fetch() and sys_arch_sem_wait() have a slightly
  different return values than in previous releases.
In ethernetif.c...
  make sure that netif->hwaddr_len is initialized to 6
In sys_arch.txt...
  just read this and follow the instructions.

In my system I have three TCP servers and two UDP servers and with the
older version of LWIP I had no known problems.  With the latest version
integrated into my system, I now notice that quite frequently when my
TCP server is blocked on lwip_recv() it does not consistently detect the
fact that the other end (the client) has closed the connection.

I had been assuming that a return value of <= 0 from lwip_recv() was
a reasonable indication that the other end had closed the connection.
Is this wrong, or can anyone think of anything else that I need to do
to transition to 0.6.2?

Thanks for any ideas!
Ed Sutter