[tz] tzcode for windows?

[random832 at fastmail.us]

On Fri, Mar 8, 2013, at 15:53, Arthur David Olson wrote:
> > Haven't looked at zdump yet, and it's less useful without the library
> > functions anyway.
> 
> In theory at least, zdump is independent of everything else in the package;
> 
> as long as the functions it calls are available all should be well.

Well, yes, but it's just dumping the MSVC implementation of timezones,
which is less useful than if I could get it to link against the tzcode
library. 

I did have to switch from environ-manipulation to putenv (need to make
it do that conditionally then I'll make a patch) and call tzset. How
exactly was it working before without ever calling tzset? Am I missing
something? Or is it just that most unix implementations, and the tzcode
implementation, happen to be tolerant of calling localtime without
calling tzset?