[tz] zic changes (2/2)

[Aurelien Jarno]

On 2016-03-02 18:43, Guy Harris wrote:
> On Mar 2, 2016, at 6:08 PM, Paul Eggert <eggert at cs.ucla.edu> wrote:
> 
> > Brian Inglis wrote:
> >> On 2016-03-02 16:19, Ian Abbott wrote:
> >>> On 03/02/16 23:02, Paul Eggert wrote:
> >>>> The TZ string "PST+8PDT" doesn't conform to POSIX,
> >>> It doesn't?
> >> 
> >> It does appear to conform - see:
> >> 
> >> http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03
> > 
> > It "conforms" in the sense that its syntax matches the POSIX spec. However, no semantics are specified by POSIX for what daylight-saving rules are in effect when TZ="PST+8PDT" is in the environment.  Glibc is within its rights, for example, to assume that DST in effect only one second during the year -- or even not in effect any time.
> 
> The same, of course, applies to PST8PDT and so on; it's not as if the "+" is somehow magical.  (I presume Aurelien put it in there to force the glibc time zone code *not* to treat the TZ value as a tzdb compiled file name.)

This value is part of the mercurial testsuite, which now fails to pass
on 32-bit machines due to this issue. It passes on 64-bit machines, so I
guess that's why the problem hasn't been encountered by the developers.
See:

https://selenic.com/hg/file/e96d2956eb4a/tests/test-parse-date

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien at aurel32.net                 http://www.aurel32.net