Difficulty building on MacOSX

[Mike Alexander]

--On May 5, 2015 at 6:18:09 PM -0700 John Ralls <jralls at ceridwen.us> 
wrote:

> I obviously haven’t encountered that problem, and ISTM our
> environments for this purpose should be pretty much identical, at
> least when you’re using the Xcode compiler. The one possibility
> that comes to mind is optimization: I’m building with -O0 so that I
> can easily use the debugger.
>
> You can cd to src/libqof/qof and make check; you should get the same
> crash on test-gnc-timezone if you have google test or on test-qof if
> you don’t. That will provide a convenient program to run the
> debugger on to see if you can get some more info.
>
> The stack trace looks like the problem is coming from trying to reuse
> a supposedly freed block, so the real bug is probably somewhere else.
> Try setting $MallocScribble and see if it will crash where the real
> bug is.

I just pushed a change that seems to fix this.  The thing about my 
setup that caused the failure is that (for reasons I haven't 
investigated) sizeof(time_t) is 8 but I have a version 1 tzfile.  The 
code that parsed the timezone file was using sizeof(time_t) for the 
size of the offsets in the file, but a version 1 file has 4 byte 
offsets no matter what sizeof(time_t) is.  This meant that it was byte 
swapping stuff that wasn't in the input buffer (as well as putting junk 
in the transitions list, of course).

I also pushed a trivial change to support version 3 tzfile format. 
Version 3 is essentially identical to version 2 and the differences 
don't seem to matter to this code.

If you think my change is inappropriate let me know and I'll back it 
out.

               Mike