From: Nikita Popov <nikita.ppv@gmail.com>
To: musl@lists.openwall.com
Subject: [musl] Re: strftime %Z behavior with manually populated struct tm
Date: Wed, 12 Aug 2020 16:05:18 +0200 [thread overview]
Message-ID: <CAF+90c-S3VQNG98SOi6pDP5Adx7y1_jTGSMb1+g2Q2bHYB8q3w@mail.gmail.com> (raw)
In-Reply-To: <CAF+90c8MDdtAZEFX5Ga-Sds1HwnwRDqc6g3ySY8f_E-0HxhujA@mail.gmail.com>
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On Wed, Aug 12, 2020 at 2:57 PM Nikita Popov <nikita.ppv@gmail.com> wrote:
> > I haven't checked, but I believe most implementations just print the
> > zone name from the current timezone, using tm_isdst to decide whether
> > to print the standard or daylight version of the name. This is
> > insufficient with zoneinfo for zones where the name changed over time,
> > where it would print the wrong name for historical times. So instead
> > we support printing any one of the zone names from the current zone,
> > if the tm_zone member points to one of them, and blank otherwise.
>
> You are right. I was under the impression that glibc uses tm_zone, but
> double checking the implementation right now, it doesn't. So the behavioral
> discrepancy here comes from the fact that musl checks tm_zone at all, not
> the other way around. Sorry for looking in the completely wrong direction
> here.
>
Nevermind, I just confused myself further here. glibc does use tm_zone,
with the following comment:
/* The POSIX test suite assumes that setting
the environment variable TZ to a new value before calling strftime()
will influence the result (the %Z format) even if the information in
TP is computed with a totally different time zone.
This is bogus: though POSIX allows bad behavior like this,
POSIX does not require it. Do the right thing instead. */
zone = (const char *) tp->tm_zone;
Regards,
Nikita
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next prev parent reply other threads:[~2020-08-12 14:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-10 13:31 [musl] " Nikita Popov
2020-08-10 16:53 ` Rich Felker
2020-08-12 12:57 ` [musl] " Nikita Popov
2020-08-12 14:05 ` Nikita Popov [this message]
2020-08-12 15:17 ` Rich Felker
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