NSS error reporting (bug 20532)

[Carlos O'Donell]

On 08/04/2017 11:08 AM, Florian Weimer wrote:
> In short, if we made this change, way too much code would break.

I half expected this answer, which is why my original suggestion had
save/restore errno and then modify it in the outbound case.

We have a decision to make, and I would err on the side of caution,
which means we have to break POSIX requirements here, and accept that
getpwnam_r modifies errno in the event of an error even if POSIX says
it doesn't, which means we change errno when the user isn't expecting.

At least initially I think that saving/restoring errno is thew way to
go here to provide some level of isolation.

-- 
Cheers,
Carlos.