[tz] zic changes (2/2)

[Aurelien Jarno]

Hi,

On 2014-05-01 16:38, Paul Eggert wrote:
> Thanks for fixing that.  I installed those patches into the experimental
> github repository, along with the attached news item for this.

> From ebd01ad62ec849fbb6fcda66df4c3e1df1e53d61 Mon Sep 17 00:00:00 2001
> From: Paul Eggert <eggert at cs.ucla.edu>
> Date: Thu, 1 May 2014 16:36:16 -0700
> Subject: [PATCH] * NEWS: Document zic change for low-valued time stamps.
> 
> ---
>  NEWS | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/NEWS b/NEWS
> index 1ef2764..2c289f5 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -5,6 +5,9 @@ Unreleased, experimental changes
>  
>    Changes affecting code
>  
> +    zic now generates transitions for minimum time values, eliminating guesswork
> +    when handling low-valued time stamps.  (Thanks to Arthur David Olson.)
> +

Sorry to come back to this patch so long after it has been committed.

It happens that this patch causes the generated zoneinfo files to not
behave correctly wrt daylight saving time on 32-bit machines. On 64-bit
machines or before this patch one get:

  $ TZ=PST+8PDT date --date=@1152995400
  Sat Jul 15 13:30:00 PDT 2006

With this patch on 32-bit machines, one get:

  $ TZ=PST+8PDT date --date=@1152995400
  Sat Jul 15 12:30:00 PST 2006

As you can see the daylight saving time is not applied.

I don't know if it is a problem in zic or a problem on the GNU libc
which doesn't correctly interpret the file. This is reproducible with
GNU libc from git as the date of today.

Any help would be appreciated.

Thanks,
Aurelien

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