3.1p1 breaks X11 forwarding

[Kevin Steves]

On Tue, 12 Mar 2002, Bob Proulx wrote:
:> Some X11 apps are "difficult" when it comes to $DISPLAY and 127.0.0.1 -
:> there was a long thread in the mailing list about this a few months ago.
:
:I will have to search the archives some more and see what that was all
:about.  On the surface it makes no sense to me that a program would
:know the difference between "localhost" which resolves to 127.0.0.1
:which is a valid address and "hostname" which resolves to 15.6.91.87
:which is also a valid address.  [Something to do with the old unix:0
:issue?]  But if this has all been discussed before I don't want to
:drag people down again with it now.

it has to do with aggresive optimizations and assumptions made in Xlib
about when an inet display should really mean to use the local transport.
there are also issues with X authority handling where "127.0.0.1" is
special-cased to FamilyLocal.

HP does something special when display is hostname, which is why we have
IPADDR_IN_DISPLAY.