Re: Testing redisplay code in batch

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Date: Wed, 23 Sep 2020 19:16:01 -0400
> Cc: emacs-devel@gnu.org
> 
> This means: with this patch, the xdisp-tests.el succeeds or not in batch
> mode depending on whether the resize_mini_window patch has been applied!
> 
> Yay!
> 
> WDYT?

Thanks.  I have a couple of minor comments:

> +      if (FRAME_INITIAL_P (f))
> +        paused_p = false;       /* No actual display to update!  */

I'd appreciate a comment here saying why setting paused_p to false is
the consequence of "no display to update".

> -  /* 10 is arbitrary,
> +  /* 80/40 is arbitrary,

Why not 80x25?  Those are the standard dimensions of old TTYs, so 25
sounds more natural to me than 40.

> @@ -1136,6 +1136,7 @@ make_initial_frame (void)
>      init_frame_faces (f);
>  
>    last_nonminibuf_frame = f;
> +  echo_area_window = f->minibuffer_window;

Why is this bit needed?

> -	  move_it_by_lines (&it, 0);
> +	  move_it_by_lines (&it, 0); /* bug#43519 */

This is unrelated (and unneeded, IMO).

> @@ -15414,8 +15414,8 @@ redisplay_internal (void)
>    /* No redisplay if running in batch mode or frame is not yet fully
>       initialized, or redisplay is explicitly turned off by setting
>       Vinhibit_redisplay.  */
> -  if (FRAME_INITIAL_P (SELECTED_FRAME ())
> -      || !NILP (Vinhibit_redisplay))
> +  if (/* FRAME_INITIAL_P (SELECTED_FRAME ())
> +       * || */ !NILP (Vinhibit_redisplay))
>      return;

This should be done cleaner, and should also update the commentary.

How about a small NEWS item about this?