Building phobos with wine fails

[Jonathan M Davis via Digitalmars-d]

On Monday, July 03, 2017 19:57:35 Shachar Shemesh via Digitalmars-d wrote:
> On 03/07/17 16:59, Jonathan M Davis via Digitalmars-d wrote:
> > 1. The functions for converting to and from a timezone take a struct
> > containing information about what that timezone is - including the DST
> > switches. The way that MS did that orginally involved specifying
> > something like the nth instance of the xth day of the week in a
> > particular month (e.g. the first Sunday in April), and that was for all
> > time, as if time zones never changed when they have DST switches -
> > which of course, doesn't work well for many timezones (there's even a
> > wikipedia article on how Windows kept having the time wrong in Israel
> > because of this). MS didn't bother to fix this until the US and Canada
> > changed when DST was going to be starting in 2007.
>
> Considering that wikipedia article used to link to *my* site for how to
> fix this, I think I safely say "I know".
>
> In fact, MS used to link to my site for a solution, which hilarious,
> because by "my site", I mean "my company", which was named "Lingnu Open
> Source Consulting Ltd.".

LOL. I did not know that, though since IIRC, you're one of the guys who
works at Weka, it does not surprise me that you'd be aware of how badly MS
has dealt with Israel and time zones.

> > Without that change, you end up using the old DST rules,
> > and last time I checked, wine had not made that change. So, if you used
> > the old functions (which IIRC, std.datetime does, because at the time
> > it was written, we were trying to support Windows XP), and you use
> > wine, then DST will be wrong for some dates which would be correct on
> > Windows.
>
> Sounds easy enough to both create a unit test and fix. Let's see if
> Alexandre will take my patches after so many years[1] :-).

It probably isn't terribly hard. I've just never gotten around to dealing
with it.

> > 2. The time zone conversion stuff in Windows is unfortunately defined in
> > the registry, and AFAIK, the only way to look up an arbitrary time zone
> > instead of using local time or UTC is to read in the information from
> > the registry and fill in the aforementioned struct with time zone
> > information with that information. The time zones are listed in the
> > registry based on the English names that MS uses - e.g. "Pacific
> > Standard Time" is what they use for the Pacific time zone (though it
> > has both the standard time and DST information in there). Pretty much
> > every other OS uses the time zone database for their time zone
> > information, and that uses major cities to distinguish time zones (e.g.
> > the Pacific time zone would be "America/Los_Angeles"), not something
> > like "Pacific Standard Time". wine chose to use the time zone database
> > names like "America/Los_Angeles" in their registry instead of the names
> > that Windows uses
>
> That one sounds like potentially harder to fix. I'll ask on the wine
> lists and see if anything comes up.

Yeah, it wouldn't surprise me if wine were doing something where it expected
to be able to link the registry keys to the time zone files on disk (I don't
know why else they would have done it that way). And as such, it's probably
not exactly a quick and easy fix. All of that is probably at least somewhat
buggy though given the discrepancies between the time zones that *nix uses
and the ones that Windows uses. Fortunately, few programs are going to care
about the exact conversions at any specific point in time so long as it's
close. But regardless, what they've done with the registry keys makes it
impossible to look up a specific time zone without realizing that you're
running in wine and doing something differently for wine (which goes against
the whole bug-for-bug compatibility thing).

> Also, note that even if I submit patches, and they get merged, it's
> around a year until major distributions pick that up.
>
> Still, better late than never.

Indeed.

- Jonathan M Davis