ws2_32: Update WS_get_local_ips to not return a bogus IP address.

[Jamie Taylor]

On Tue, Nov 24, 2015 at 08:30:13PM +0800, Bruno Jesus wrote:
> Hi, Jamie. Thanks for your effort, as you may have observed in the
> patches list your patch is marked as deferred because we are in code
> freeze for Wine 1.8 release. This code was touched a few times in
> attempts to fix this same issue you are addressing so maybe this time
> it will be the definitive fix =)

Hello, Bruno.  Thanks for your review.

I think that a true definitive fix would include removing the magic
loopback address completely, as it's obviously a hack (and not a value
that would ever be returned by Windows).  That seems like a much more
invasive change.

> I have a similar (not so robust) old patch that I used on FreeBSD (and
> also works in Linux), could you try it in OSX just out of curiosity,
> please? It has printf to help showing the results so a make test in
> the ws2_32/tests folder is enough to check if it works.

Yes, that patch works for me.  The main difference is that it includes
the magic loopback address in the returned list if there are any routes
to a loopback interface in the forwarding table (actually, one copy of
the magic loopback address per loopback interface, I think... but there's
generally only one loopback interface).  And it doesn't return all of
the addresses from an interface (although I've never actually seen one
have more than one address - but the data structure supports it).

Is the resulting list of addresses supposed to contain loopback addresses?
(I.e., does it on Windows?  I don't have a Windows machine on which to
test.)  If so, then the patch that I submitted is deficient in that
regard, as it will never return addresses from loopback interfaces.
(Of course, the existing implementation and your patch will both return
the magic loopback address rather than any addresses actually assigned
to the interface, but that's a different problem.)

In any case, either patch will solve the specific problem that I was
trying to solve (getting the correct IP address displayed when hosting
a Diablo 2 game), so in that respect I don't care which one makes it
into a release.  (In fact, now that I have a Wineskin with a custom
wine build that works for me, I don't care if it ever makes it into
a release - but I assume other people who don't have the ability to
fix it themselves would like it, which is why I submitted a patch
in the first place.)

> About your patch I just would like to say that you should follow the
> surrounding code style, so the { goes in the next line. I tested it on
> Linux and it works for Heroes of Might & Magic 2
> (https://bugs.winehq.org/show_bug.cgi?id=22819).

I was following the style used by 4 of the 7 opening braces in
WS_gethostbyname (for which WS_get_local_ips is a helper, and
which appears immediately following WS_get_local_ips in socket.c).
Perhaps someone should change the 10% of the open braces in this file
that do not appear alone on their lines if they are all meant to use a
consistent style?

And speaking of style, I suppose the indentation should be 4 spaces
rather than whatever default my editor used?

Jamie