Re: [MPS-test] scratch/igc branch (commit: 42731228d24) crashed

[Eli Zaretskii <eliz@gnu.org>]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: Eval Exec <execvy@gmail.com>,  emacs-devel@gnu.org
> Date: Mon, 05 Aug 2024 17:47:10 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > I guess no one has yet built the branch with Lucid toolkit?  Maybe the
> > scroll bars etc. in that build are not handled correctly?
> 
> Could also be, yes.

Look here (xterm.c):

#ifndef USE_MOTIF
      hints_changed
	= widget_update_wm_size_hints (f->output_data.x->widget,
				       f->output_data.x->edit_widget);
#else

We call widget_update_wm_size_hints with f->output_data.x->widget, but
output_data.c->widget hides a pointer to 'struct frame':

bool
widget_update_wm_size_hints (Widget widget, Widget frame)
{
  return update_wm_hints ((WMShellWidget) widget, (EmacsFrame) frame);
}

and update_wm_hints does:

  pixel_to_char_size (ew, ew->core.width, ew->core.height,
		      &char_width, &char_height);

which does

static void
pixel_to_char_size (EmacsFrame ew, Dimension pixel_width,
		    Dimension pixel_height, int *char_width, int *char_height)
{
  struct frame *f = ew->emacs_frame.frame;

So if the frame object is moved and
f->output_data.x->widget->emacs_frame.frame is not updated, we are
toast, right?