Re: emacs rendering comparisson between emacs23 and emacs26.3

[martin rudalics]

>> I tried that now and it makes no noticeable difference here.  Maybe I
>> did something wrong - all I checked via GDB was that it does perform
>> the specbinding.  Maybe that's not sufficient.
>
> That's not so good.  The way it works is by bypassing the fontification
> in the scrolling code (which is only there to calculate how many lines to
> scroll, particularly for variable height fonts).  The only fontification
> should happen for redisplay, and that only for when there's no input
> event waiting.
>
> So if all works well, only isolated small segments of the buffer
> (screenfuls) get fontified and displayed and no long queue of buffer
> portions for fontification should build up.
>
> I don't know why it's not working for you.

As a matter of fact, it is slightly better.  Still, Emacs locks down
after a few scrolls in a similar way as without it.

martin