[tz] A small first step in merging NetBSD changes into tzcode

[Paul Eggert]

On 2023-01-05 05:39, Ian Abbott via tz wrote:
> The Linux man page for GNU gettext claims that errno is not modified, 
> but the NetBSD man page for Citrus gettext makes no such claim.  Better 
> safe than sorry!

Yes, glibc gettext started preserving errno in glibc 2.1 (1999) though 
at least one bug in this area was not fixed until glibc 2.21 (2015).

As I recall the original gettext (introduced in SunOS 4, around 1990) 
did not preserve errno; at any rate the still-supported Solaris 10 
gettext has a man page that doesn't say it preserves errno. Although 
it'd be nice if Solaris, NetBSD etc. gettext were changed to preserve 
errno, portable code shouldn't assume it.