[tz] 回复: 回复: zoneinfo generating issues

Ian Abbott abbotti at mev.co.uk
Fri Mar 12 09:55:36 UTC 2021

On 07/03/2021 02:07, Paul Eggert wrote:
> For clients using TZif files with leap second support, we have three 
> objectives:
> A. Fix and/or work around the longstanding localtime.c bug.
> B. Clients should be able to deduce when the leap second table expires.
> C. Clients should be able to predict timestamps after the expiration 
> date more accurately than just "assume the latest-known UTC offset".
> The second change supported (A) and (B), but broke (C).
> Given the problems you described, I installed the attached patch, which 
> omits the truncation introduced in tzdb 2020a. This fixes (C), but 
> breaks both (A) and (B). I'll try to think of a better way to support 
> (A) and (B).

For (B), would adding an extra leap-second record at the expiry time 
with no difference in correction value work? That would not conform to 
RFC 8536, but seems unlikely to break any thing unless that thing is 
strictly checking that correction values differ by exactly 1.

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