[GRASS5] Re: [bug #4155] (grass) d.m will not display remotely

[Glynn Clements]

Kirk R. Wythers wrote:

> > There are two possibilities that I can think of, but both are really
> > just wild guesses.
> >
> > 1. Your version of Tk relies upon additional pre-defined atoms which
> > are specific to the MacOSX X server.
> >
> > 2. It is communicating with both local and remote X servers, and using
> > XIDs obtained from one on the other.

> Thanks for your thoughts on this issue Glynn. Here is the answer (for  
> the purposes of the archives).
> 
> On OS X (Tiger 10.4) use ssh -Y, (which enables trusted forwarding).  
> and the Wish shell (built on X11 forwards fine).
> 
> Panther and earlier used a version of ssh that only used the -X  
> option for X forwarding.

Hmm.

     -Y      Enables trusted X11 forwarding.  Trusted X11 forwardings are not
             subjected to the X11 SECURITY extension controls.

That makes sense (sort of).

It appears that property accesses which are blocked by the SECURITY
extension are reported using the BadAtom error, which is rather
counter-intuitive (and not documented, AFAICT). wish tries to set an
InterpRegistry property on the root window, which is likely to be
prohibited by the default security policy.

It should be possible to change the security policy to allow such
requests (or at least silently ignore them), but "ssh -Y" (or the
ForwardX11Trusted option) is probably simpler in most cases.

-- 
Glynn Clements <glynn at gclements.plus.com>