[cairo] cairo-xlib-surface.c:402: _swap_ximage_to_native: Assertion `NOT_REACHED' failed.

[Erik Ohrnberger]

OK.  I did some more testing, and I think I've got more clues to this issue.

When I run startx on the console, everything works fine.  The applications
start up and run as expected.

Generally, I'm running an X Window server emulator on my Windows PC and pipe
the display up there.  The PC is set to 32 bit color depth, and when the
DISLPAY env var is set to the IP of the Windows PC, that is when the
applications fail with this error.

Is there a setting someplace on the Linux side where I can force a similar
color depth as to the Option "Pixmap" "32" you mention below?

Thanks for the help, I really appreciate it.

	Erik.

> -----Original Message-----
> From: Daniel Amelang [mailto:daniel.amelang at gmail.com] 
> Sent: Saturday, November 18, 2006 2:09 PM
> To: erik at echohome.org
> Cc: cairo at cairographics.org
> Subject: Re: [cairo] cairo-xlib-surface.c:402: 
> _swap_ximage_to_native: Assertion `NOT_REACHED' failed.
> 
> On 11/18/06, Erik Ohrnberger <erik at echohome.org> wrote:
> > Dear Cairo users,
> >         I've been struggling with a Gentoo system where the error 
> > message above is causing all the program that rely on cairo, like 
> > gtkmm based programs, to core out.
> 
> In cairo-xlib-surface.c, there's a comment that warns that 
> this could happen:
> 
>     switch (ximage->bits_per_pixel) {
>  ...
>     default:
>         /* This could be hit on some uncommon but possible cases,
> 	 * such as bpp=4. These are cases that libpixman can't deal
> 	 * with in any case.
> 	 */
> 	ASSERT_NOT_REACHED;
>     }
> 
> I'm going to guess that in your case, ximage->bits_per_pixel 
> is 24, as that case also takes the default path.
> 
> >         I was wondering if there were any known issues of 
> > configuration changes that could be applied to remove this issue.
> 
> I think you can change the color depth in your Xorg.conf. I 
> think you're looking for this:
> 
> Option "Pixmap" "32"
> 
> On the other hand, maybe cairo should be able to handle 24 
> bpp, so in that case it's a bug/feature request that should 
> be filed. Carl?
> 
> Dan
>