[Xcb] connection issue using xcb in libX11

[Josh Triplett]

On Thu, Apr 29, 2010 at 03:12:43PM -0700, Alan Coopersmith wrote:
> Josh Triplett wrote:
> > I find it quite dubious that real applications expect DISPLAY=:0 to
> > connect to TCP.  It certainly violates the principle of least surprise.
> 
> But it's what the Xlib standard spec has always required.  When no hostname
> or transport protocol is provided, Xlib is supposed to pick the "best"
> transport available.  If TCP to localhost is the only one accepting
> connections, it would be the best.
> 
> xcb is of course free to implement a different spec at its level, but
> Xlib should continue to honor this when applications call XOpenDisplay()
> regardless of whether Xlib calls xtrans or libxcb to make the connection.

I agree entirely that Xlib should continue to have this fallback.

Just suggesting that we can implement this fallback in Xlib without
necessarily implementing it in XCB, so we can continue to consider
whether we *should* implement it in XCB while fixing the issue at hand
in Xlib.

- Josh Triplett