[tz] Unexpected footer in Africa/Casablanca

[Paul Eggert]

On 1/25/22 08:45, Almaz Mingaleev wrote:
> Is there a way to force TZif2 format for all time zones?

No. I suppose someone could add a '-V N' option to to zic to refuse to 
generate anything past TZif format N, for whatever value of value of N 
you like. For the case you describe, zic would generate an empty footer 
(thus refusing to predict the future) since no version-2-format footer 
would be accurate for a future that requires version 3.

However, I hope it isn't worth the trouble to write code like that. Any 
TZif parser that wasn't written to grok TZif format 3 should be doing 
something reasonable with format-3 TZ strings anyway - and if it isn't, 
I'd like to know the details before proceeding along the lines outlined 
above.

Similar thoughts apply to TZif version 2 or 3 versus version 4, which 
should be in the next TZif RFC; see 
<https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/>.