Re: signed short fd

>
>> Maybe we make the assumption that all OS will
>> implement "fd" as an array index
>
> The POSIX spec requires open() to assign fd's consecutively from zero.
> http://www.opengroup.org/onlinepubs/007908799/xsh/open.html

With all due respect, PostgreSQL now runs natively on Win32. Having a
POSIX-only mentality, especially with something so trivial, is a mistake.
I would say "int" is the best way to handle it. You just *never* know.