[tz] zic option to generate smaller output files?

[Ken Murchison]

On 11/22/2017 01:49 PM, Paul Eggert wrote:
> On 11/22/2017 02:30 AM, Zefram wrote:
>> The binary tzfile usually provides a ruleset applicable to indefinitely
>> many years, in the form of a POSIX TZ string.  But that's not the 
>> current
>> rules, it's the rules to be applied when all of the file's explicit
>> transitions have run out.
>
> Changing the subject (and subject line)....
>
> Currently zic generates a bunch of explicit transitions at the end of 
> the time transition table, even if these transitions merely repeat 
> what a TZ string would generate. This is to support older clients that 
> grok only version-1 tzfile format, and which don't know about the TZ 
> string (which was introduced in version 2 tzfile format). Since 
> version 2 format was introduced in release 2006b, I'm thinking now may 
> be a good time to add an option to zic to suppress explicit 
> transitions at the end of the table if these transitions agree with 
> the TZ string. This will help uncover buggy client code that 
> mishandles TZ string values and therefore mishandles future 
> timestamps. By default this option will be off now (meaning no change 
> to the default behavior), but we could turn it on later.

This option makes sense to me.

Would it also be possible to have this option (or a separate one) create 
the first header and body (32-bit time values) with counts of zero?  All 
of the data that would appear in that body is duplicated in the second 
body anyways.

-- 
Kenneth Murchison
Cyrus Development Team
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