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

[Michael H Deckers]

    On 2018-01-30 08:49, Paul Eggert proposed changes:

> This is intended to provide a way to support both clients that require
> data to have only positive DST offsets, and clients that do not have
> this restriction.

    What is meant here by "DST offset"? The term
    is not used nor defined in the description of
    zic input. Do you mean the values in the
    SAVE column of Rule lines in zic input?
    Probably not -- the SAVE values in
    zic input cannot be required to be positive
    as the value 00:00 must be allowed.

    So what property is guaranteed for the
    zic input pdstdata.zi?

    Michael Deckers.