[tz] [PROPOSED] Support zi parsers that mishandle negative DST offsets

[Paul Eggert]

On 02/06/2018 07:40 AM, Stephen Colebourne wrote:
> Users are encouraged to update the time-zone data themselves:
> http://www.joda.org/joda-time/tz_update.html
> http://www.threeten.org/threetenbp/update-tzdb.html
>
They should continue to be able to do that. joda.org, threeten.org, etc. 
can continue to distribute tarballs in rearguard format or whatever 
other format they like, and users can use those tarballs. Something like 
this should be done regardless of whether there is any format change, as 
iana.org doesn't have the resources to support every device on the 
planet directly.

> Since zic/make is not run, how is a downstream consumer going to use them
A process at joda.org, threeten.org, etc. can run 'make' to generate a 
tarball that contains files in rearguard format, and then joda.org, 
threeten.org etc. can redistribute that tarball. Assuming the current 
development version, the process could run something like the following, 
say.

make rearguard.zi
mkdir tzrear.dir
ln rearguard.zi tzrear.dir/africa
for file in antarctica asia australasia europe northamerica southamerica 
etcetera systemv factory backward ; do \
       touch tzrear.dir/$file || exit; \
     done
(cd tzrear.dir && \
         tar -cf - africa antarctica asia australasia europe 
northamerica southamerica etcetera systemv factory backward ) | \
       gzip >tzrear2018c.tar.gz

No doubt this will require minor tweaking to pacify whatever quirks 
OpenJDK has, but I hope you get the idea.

The point is that if OpenJDK wants a particular tweak to the format, 
then it should be in charge of its own destiny, and not be at the mercy 
of upstream changes. This is what other distributors do, and it's a good 
time for OpenJDK to start following their lead.