Subject: Re: bug#39865: 28.0.50; Emacs crash

From: Vinicius José Latorre <[email-masked]>
Date: Thu, 12 Mar 2020 21:44:15 -0300

> Vinicius, the following patch should fix things for you.

I've just reinstalled with the fix, and I confirm that all works right when
setting font-backend to xft.

On Thu, Mar 12, 2020 at 7:25 AM Robert Pluim <[email-masked]> wrote:

> >>>>> On Thu, 12 Mar 2020 10:33:00 +0100, Robert Pluim <[email-masked]>
> said:
>     Robert> Of course, what I should do is rebase
>     Robert> <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=23386#43>
>
>     Robert> Yep, that fixes this for me. Of course it breaks the macOS
> build,
>     Robert> since that doesnʼt have a gui_default_font_parameter function
>     Robert> (yet :-) ).
>
> Vinicius, the following patch should fix things for you. Iʼll have to
> look at what's needed on the macOS side.
>
> diff --git a/src/dispextern.h b/src/dispextern.h
> index 6246c7c080..f08231f071 100644
> --- a/src/dispextern.h
> +++ b/src/dispextern.h
> @@ -3726,6 +3726,7 @@ #define IMAGE_BACKGROUND_TRANSPARENT(img, f, mask)
>                             \
>                                            Lisp_Object, Lisp_Object,
>                                            const char *, const char *,
>                                            enum resource_types);
> +extern void gui_default_font_parameter (struct frame *, Lisp_Object);
>
>  #ifndef HAVE_NS /* These both used on W32 and X only.  */
>  extern bool gui_mouse_grabbed (Display_Info *);
> diff --git a/src/frame.c b/src/frame.c
> index 51fc78ab70..45fed8420c 100644
> --- a/src/frame.c
> +++ b/src/frame.c
> @@ -4565,7 +4565,11 @@ gui_set_font_backend (struct frame *f, Lisp_Object
> new_value, Lisp_Object old_va
>      return;
>
>    if (FRAME_FONT (f))
> -    free_all_realized_faces (Qnil);
> +    {
> +      Lisp_Object frame;
> +      XSETFRAME (frame, f);
> +      free_all_realized_faces (frame);
> +    }
>
>    new_value = font_update_drivers (f, NILP (new_value) ? Qt : new_value);
>    if (NILP (new_value))
> @@ -4579,10 +4583,8 @@ gui_set_font_backend (struct frame *f, Lisp_Object
> new_value, Lisp_Object old_va
>
>    if (FRAME_FONT (f))
>      {
> -      Lisp_Object frame;
> -
> -      XSETFRAME (frame, f);
> -      gui_set_font (f, Fframe_parameter (frame, Qfont), Qnil);
> +      /* Reconsider default font after backend(s) change (Bug#23386).  */
> +      gui_default_font_parameter (f, Qnil);
>        face_change = true;
>        windows_or_buffers_changed = 18;
>      }
> diff --git a/src/xfns.c b/src/xfns.c
> index 5758bb7a18..ab013d85d8 100644
> --- a/src/xfns.c
> +++ b/src/xfns.c
> @@ -3555,8 +3555,8 @@ do_unwind_create_frame (Lisp_Object frame)
>    unwind_create_frame (frame);
>  }
>
> -static void
> -x_default_font_parameter (struct frame *f, Lisp_Object parms)
> +void
> +gui_default_font_parameter (struct frame *f, Lisp_Object parms)
>  {
>    struct x_display_info *dpyinfo = FRAME_DISPLAY_INFO (f);
>    Lisp_Object font_param = gui_display_get_arg (dpyinfo, parms, Qfont,
> NULL, NULL,
> @@ -3894,7 +3894,7 @@ DEFUN ("x-create-frame", Fx_create_frame,
> Sx_create_frame,
>
>    /* Extract the window parameters from the supplied values
>       that are needed to determine window geometry.  */
> -  x_default_font_parameter (f, parms);
> +  gui_default_font_parameter (f, parms);
>    if (!FRAME_FONT (f))
>      {
>        delete_frame (frame, Qnoelisp);
> @@ -6378,7 +6378,7 @@ x_create_tip_frame (struct x_display_info *dpyinfo,
> Lisp_Object parms)
>
>    /* Extract the window parameters from the supplied values that are
>       needed to determine window geometry.  */
> -  x_default_font_parameter (f, parms);
> +  gui_default_font_parameter (f, parms);
>
>    gui_default_parameter (f, parms, Qborder_width, make_fixnum (0),
>                           "borderWidth", "BorderWidth", RES_TYPE_NUMBER);
>