[gnu.emacs.bug] Can't use local display with remote hosts in X11R3

tale@its.rpi.edu (David C Lawrence) (03/25/89)

Sorry to be bothering everyone with this, but my beginning knowledge
of X has not been able to get me through this problem.  We've just
installed Emacs 18.53 on our Sun 3, SunOS 4.0.1 system and are having
a problem with Emacs' handling of displays.  The problem in general
seems to be that Emacs just won't open up a TCP/IP display.

A more specific example:
I login to consult1.its.rpi.edu and fire up my X11R3 server with
vanilla uwm.  I turn around and login to risk.its.rpi.edu, an
identical (for all practical purposes) machine.  From risk, I start
"emacs -display consult1.its.rpi.edu:0" and it complains about not
being able to connect to the X server; in fact, if I try using that
display from consult1, it still balks, although -display unix:0 works
as it should.  The problem does not seem to be with our network or
with X, as other X tools (xterm, xclock, xcalc, et al) work as
expected.

If anyone has any advice into this matter, I would greatly appreciate
it.  We seem to have a pretty standard configuration and why this
doesn't work is a complete mystery to me.

(By the way, looking at the code for x11term.c it appears as though
checking of the DISPLAY environment variable was taken out; is this
now directly supported in X11, making such a check unnecessary?)

Dave
--
      tale@rpitsmts.bitnet, tale%mts@itsgw.rpi.edu, tale@pawl.rpi.edu

weltyc@cs.rpi.edu (Christopher A. Welty) (03/29/89)

In article <TALE.89Mar25022854@ts.its.rpi.edu> tale@pawl.rpi.edu writes:
>
>A more specific example:
>I login to consult1.its.rpi.edu and fire up my X11R3 server with
>vanilla uwm.  I turn around and login to risk.its.rpi.edu, an
>identical (for all practical purposes) machine.  From risk, I start
>"emacs -display consult1.its.rpi.edu:0" and it complains about not
>being able to connect to the X server; in fact, if I try using that
>display from consult1, it still balks, although -display unix:0 works
>as it should.  The problem does not seem to be with our network or
>with X, as other X tools (xterm, xclock, xcalc, et al) work as
>expected.

In order for one machine to behave as a client to a server running on
another machine, the server machine must have the client machine
listed in its `hosts that are permitted to use me' list (accessed
through the `xhost' command).  In your case, it seems running:

consult1.its.rpi.edu% xhost risk.its.rpi.edu consult1.its.rpi.edu

will work.  I know 18.53 and 18.52 work with X both locally and
remotely since I am using it now.  If this does not solve your problem
you may give me a call or send me mail.

Christopher Welty  ---  Asst. Director, RPI CS Labs | "Porsche:  Fahren in
weltyc@cs.rpi.edu             ...!njin!nyser!weltyc |  seiner schoensten Form"