Re: getspnam: errno=ENOENT for absent user

[Szabolcs Nagy <nsz@port70.net>]

* Philippe Grégoire <pg@pgregoire.xyz> [2018-12-25 17:07:14 -0500]:
> I'm working with saltstack on Alpine Linux and am getting trouble
> managing users. I tracked the problem down to musl and the fact
> that getspnam sets errno to ENOENT when a user is missing. This
> behavior differs from glibc which leaves errno to 0 and makes
> the user relies on the return value; when the name is missing.
> 
> Semantically, ENOENT makes sense, but this is breaking compatibility
> with other softwares, at the moment. I'll send a patch over to
> saltstack so that current systems are supported, but believe it
> should be fixed here too for future compatibility. What do you think?

based on

http://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwnam.html
"If the requested entry was not found, errno shall not be changed."

this should be fixed in musl.

> 
> Please, Cc me for reply as I'm not subscribed.
> 
> 
> Program to demonstrate the issue:
> 
> #include <errno.h>
> #include <shadow.h>
> #include <stdio.h>
> int main(void)
> {
>         errno = 0;
>         void* r = getspnam("enoent);
>         perror("getspnam");
>         printf("%p\n", r);
> }
> 
> On Debian:
> getspnam: Success
> (nil)
> 
> On Alpine:
> getspnam: No such file or directory
> 0