Re: emacs rendering comparisson between emacs23 and emacs26.3

[Dmitry Gutov]

Hi Alan,

On 05.04.2020 22:57, Alan Mackenzie wrote:
> Try this:
>
> diff --git a/src/window.c b/src/window.c
> index 8cdad27b66..b23ae41aba 100644
> --- a/src/window.c
> +++ b/src/window.c
> @@ -5475,7 +5475,9 @@ window_scroll (Lisp_Object window, EMACS_INT n, bool 
> whole, bool noerror)
>   
>     wset_redisplay (XWINDOW (window));
>   
> -  if (whole && Vfast_but_imprecise_scrolling)
> +  if (Vfast_but_imprecise_scrolling
> +      && (whole
> +          || EQ (Vthis_command, Qmwheel_scroll)))
>       specbind (Qfontification_functions, Qnil);
>   
>     /* On GUI frames, use the pixel-based version which is much slower
> @@ -8173,6 +8175,7 @@ syms_of_window (void)
>     DEFSYM (Qmode_line_format, "mode-line-format");
>     DEFSYM (Qheader_line_format, "header-line-format");
>     DEFSYM (Qtab_line_format, "tab-line-format");
> +  DEFSYM (Qmwheel_scroll, "mwheel-scroll");

You probably meant to address Martin, but I can just say that while this 
will almost certainly work, it doesn't address the scenario of flooring 
C-v. Or M-v. Etc. Which seem equivalent.