How is display of images prevented on text-only frames?

How is display of images prevented on text-only frames?

[joakim]

I cant seem to figure it out.

My concrete problem is that I wind up here, term.c 1563:

void
produce_glyphs (struct it *it)
{
  /* If a hook is installed, let it do the work.  */

  /* Nothing but characters are supported on terminal frames.  */
  eassert (it->what == IT_CHARACTER
	   || it->what == IT_COMPOSITION
	   || it->what == IT_STRETCH
	   || it->what == IT_GLYPHLESS);

... with a xwidget, and then the assert gets upset.

Images doesnt seem to wind up here though.

-- 
Joakim Verona

Re: How is display of images prevented on text-only frames?

[Eli Zaretskii]

> From: joakim@verona.se
> Date: Fri, 30 Jan 2015 16:32:47 +0100
> 
> I cant seem to figure it out.

They are ignored in handle_single_display_spec, if the frame is not a
GUI frame.  See the code around line 5125 in xdisp.c (on master).

> void
> produce_glyphs (struct it *it)
> {
>   /* If a hook is installed, let it do the work.  */
> 
>   /* Nothing but characters are supported on terminal frames.  */
>   eassert (it->what == IT_CHARACTER
> 	   || it->what == IT_COMPOSITION
> 	   || it->what == IT_STRETCH
> 	   || it->what == IT_GLYPHLESS);
> 
> ... with a xwidget, and then the assert gets upset.
> 
> Images doesnt seem to wind up here though.

Indeed, since they are no produced at all in that case.