Re: guile-gtk images on remote X display

[Greg Badros <gjb@cs.washington.edu>]

"Marisha Ray & Neil Jerram" <mpriz@dircon.co.uk> writes:

> Well it's wrong, of course, to be trying to use the MIT-SHM extension when
> the client and X server are on different machines.  But you probably already
> knew that.
> 
> I suggest you investigate the place in the GTK code where it makes on
> decision on whether to try to use MIT-SHM - there must be a bug there.
> 
> In cases where it is valid to use MIT-SHM, a common error scenario is where
> the client's image data gets freed or overwritten before the XShmCompletion
> event arrives - a symptom of which can be that you see garbage images.
> 
>     Neil (hoping I'm not just stating the obvious)

Right-- see the scwm-discuss archives for my detailed description of the 
problem and how I fixed it.  In a nutshell, GTk relies on its X11 error
handler to report errors, but Scwm was replacing that error handler w/o
side-effecting the global variable the GTk expected to hold the last X11 
error code.  The fix was simple once I discovered the use of the error
handler and the setting of the global variable.

Thanks for your help.

Greg