Support non-POSIX TZ strings

[Jeff Johnston]

On Mon, Feb 14, 2022 at 3:46 PM Brian Inglis <
Brian.Inglis@systematicsw.ab.ca> wrote:

> On 2022-02-14 12:58, jdoubleu wrote:
> > On 22-02-14 10:10-0700, Brian Inglis wrote:
>
> >> [..] but we should start with the actual POSIX spec under TZ
>
> > Yes, that is exactly what I meant: Newlib supporting the <> (angle
> > brackets) syntax.
> > I didn't know that it was actually part of POSIX spec, since so many
> > libs actually don't implement it.
>
> Most should have by now if maintained: we should be a laggard! ;^>
>
> >> The BSD or TZcode implementations could probably be adapted [..]
>
> > It looks like the TZcode implementation by Paul Eggert uses a different
> > approach to parsing the strings, than the current implementation in
> > newlib
> > (
> https://sourceware.org/git/?p=newlib-cygwin.git;a=blob;f=newlib/libc/time/tzset_r.c).
>
> > I'm not sure, if you want to copy the code over or use changes by e.g.
> > Earle F. Philhower from
> > https://github.com/earlephilhower/newlib-xtensa/pull/14.
> > Because of the above question, I'm not sure how to continue on this. I
> > would like to contribute myself and submit an implementation, but I'll
> > wait for feedback by other maintainers, first.
>
> Upstream sources like BSDs or TZcode official reference implementations
> are normally preferred because they are feature complete, regularly
> maintained, feature test and standards compliant, vulnerabilities
> checked, issues reported, and promptly fixed.
>
> I checked the BSDs and they seem to have adopted or adapted the TZcode
> official reference implementation, so I am not sure from where it may
> have been adopted, or whether it is original: the maintainer Jeff
> Johnson may remember.
>

Unfortunately, I do not remember the exact details from back then.  With no
license header, it means it was written by Cygnus/Red Hat.



> I also wonder if the GMT defaults should be updated to UTC.
>
> --
> Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
>
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