Re: Confusing "Success" error message

[Eli Zaretskii]

> Date: Fri, 8 Nov 2019 15:03:21 +0100
> From: "Andries E. Brouwer" <address@hidden>
> Cc: Francesco Turco <address@hidden>, address@hidden,
>  "Andries E. Brouwer" <address@hidden>
> 
> > Libc functions only touch errno if there *is* an error
> 
> Libc functions are free to call other functions internally,
> and such internal calls may fail where the outer level call
> does not fail. So even if a libc function does not return
> an error, errno can have changed.

That would be a bug in libc, I think.  Its functions should save and
restore errno if other functions they call error out without causing
the calling function to fail.

IOW, if a libc function succeed, it should whatever it takes to
preserve errno.