How does X Server assign Window ID?

[Glynn Clements]

Sheng Yu wrote:

> I tried generating two windows and draw on the second window in
> displays ':2.0' and ':2.1'.
> This makes the window id used for rendering different from the windows
> in displays ':1.0'
> and ':1.1'. And it works! The function glXMakeCurrent() does not
> crash, and the rendering
> also seems to be correct.
> 
> I looked into the source code of GLX, and I cannot find any clue that
> the same window id
> will cause this function to crash with a segmentation fault. Could it
> be possible that it is a bug
> in the graphics driver?

Your findings suggest that something may be treating window IDs as
being unique globally rather than per-display.

If you're using a proprietary OpenGL driver, that would be a prime
suspect. Try forcing indirect rendering with AIGLX disabled (and
without nVidia's libGL, if you're using that).

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