bug#10021: [PATCH id] Add error-checking on GNU

[Ludovic Courtès]

Hi,

"Alan Curry" <address@hidden> skribis:

> Ludovic =?UTF-8?Q?Court=C3=A8s?= writes:
>> 
>> OTOH, on POSIX-conforming systems (which includes GNU/Linux, so it may
>> be the majority of systems in use), -1 may well be a valid UID/GID.
>
> That's a bizarre statement.
>
>   3.428 User ID
>
>   A non-negative integer

It’s always non negative since glibc defines it as unsigned (see
__UID_T_TYPE in typesizes.h.)

I really meant 2^32 - 1.

Thanks,
Ludo’.