Re: [PATCH]: Fix for several getdate.y issues (amended patch #3)

[Jim Meyering]

Ondřej Vašík <address@hidden> wrote:
> Hello,
> as discussed with Jim Meyering via IRC, I'm sending changed version of
> the patch #3 to the list. This one patch adds range to valid TZ and
> handles correctly hours when no minutes are specified (until that patch
> is UTC+14 handled incorrectly as UTC+0:14) and are in common range of
> UTC-12 to UTC+14.
> Although there are few different implementations of TZ limits (Microsoft
> uses range UTC-14 to UTC+14 , various sources show that only TZ between
> UTC-12 and UTC+14 are in use), this patch uses range UTC-24 to UTC+24 as
> recommended for TZ environmental variable in POSIX
> (http://www.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html).
> After applying that patch invalid TZ will show an invalid date format
> error (because of double increment of pc->zones_seen).
> I added few tests to gnulib getdate test suite to check if various TZ
> formats are showing the same result.
>
> Greetings,
>          Ondrej Vasik
>
>
> From 1c284d1a4155136ddaee44eab7fd5d55a75962fc Mon Sep 17 00:00:00 2001
> From: =?utf-8?q?Ond=C5=99ej=20Va=C5=A1=C3=ADk?= <address@hidden>
> Date: Fri, 4 Jul 2008 17:44:57 +0200
> Subject: [PATCH] getdate.y: add limits for TZ, handle TZ +HH format correctly
>
> * lib/getdate.y (time_zone_hh_mm): Allow only TZ in the range
> UTC-24 to UTC+24 hours, consider first two digits of TZ as hours
> when no minutes are specified and number is in the range -14
> and +14 (as common TZ ranges UTC-12 to UTC+14). Invalid TZ will
> cause invalid date format error.
> * tests/test-getdate.c: Tests for that change
> ---
>  ChangeLog            |    9 ++++++++
>  lib/getdate.y        |   35 ++++++++++++++++++++++++++-------
>  tests/test-getdate.c |   51 
> ++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 87 insertions(+), 8 deletions(-)
>
> diff --git a/ChangeLog b/ChangeLog
> index 6c5f522..076d70e 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,12 @@
> +2008-07-04  Ondřej Vašík  <address@hidden>
> +
> +     getdate.y: Allow only timezone range specified by POSIX
> +     * lib/getdate.y (time_zone_hhmm): Allow only TZ in the range
> +     -24 to +24 hours, consider first two digits between -14 and 14
> +     as hours (as common TZ ranges UTC-12 to UTC+14). Invalid TZ
> +     will cause invalid format error.
> +     * tests/test-getdate.c: Tests for the fix

Hi Ondřej,

I'm a little leery of this patch, because it makes interpretation
of UTC+dd and UTC-dd dependent on the value of dd.  For dd <= 14, dd
represents hours.  Otherwise, it represents minutes.  That would have
to be documented, but seems odd enough that my reflex is to avoid the
change so I don't have to document something so strange.

However, Paul Eggert is the official maintainer of this package,
so let's see what he thinks.

Paul, for more context, here's the original thread:
  http://thread.gmane.org/gmane.comp.lib.gnulib.bugs/13986/focus=14012