Re: [bug #28590] Cairo backend displays wrong colors on X server with a different endianness

[Derek Fawcus]

[from bug-gnustep]

On Wed, Jan 20, 2010 at 02:47:38PM +0000, Fred Kiefer wrote:
> 
> And we only need to change any code in the case where we
> don't use shared memory (this is for some reason broken on modern X Servers
> and I don't have a clue).

Broken how?  Note that shared pixmaps are an optional part of MIT-SHM support,
and that recent Xorg servers have it disabled by default.

I see that the XWindowBuffer.m code tries to use shared XImages and shared
Pixmaps,  and hence if shared pixmaps are disabled,  disables all X shm
support.  i.e. this bit:

  if (!XShmQueryVersion(display, &major, &minor, &pixmaps) || !pixmaps)

Could the code be usefully restructured to use shared Ximages without
the need for shared pixmaps?  Since it only seems to be used for the
window background,  possibly so by adjusting the above to ignore
the chared pixmap support,  and removing the line that tries to create
the shared pixmap.