bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?

[Stefan Kangas]

Robert Pluim <rpluim@gmail.com> writes:

>     Ihor> False-positives are indeed not unexpected in char-displayable-p; 
> just as
>     Ihor> its docstring warns. However, I am now wondering if there is some 
> more
>     Ihor> accurate way to know if a character can be actually displayed on 
> buffer
>     Ihor> or not.
>
> Iʼd look at the guts of `describe-char-display' in
> "lisp/descr-text.el" for inspiration (or even use it as is). It takes
> a `pos' argument so you may have to wrap it in `with-temp-buffer' +
> `insert'.

I know very little about this area of Emacs, but is there any reason why
we couldn't just (try to) make `char-displayable-p' more accurate?

I'm not asking for a perfect solution, but even just making it a bit
better might be a step forward.