Re: master 15afa72460b: Fix 'script-representative-chars' for the 'han' script

[Po Lu <luangruo@yahoo.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Po Lu <luangruo@yahoo.com>
>> Cc: emacs-devel@gnu.org
>> Date: Wed, 07 Aug 2024 08:17:08 +0800
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > Note that I said "if you remove those characters".
>> >
>> > If you did note that, then does it mean when U+2F75 needs to be
>> > installed and the current font for han doesn't support it, Emacs will
>> > never try to look for _another_ font which supports han characters?
>> > Or will it try, but always fail?
>> 
>> How do you mean?  During Emacs's search for a suitable font, it is yet
>> to decide what is the "current font for han."
>
> I mean the following scenario:
>
>   . start Emacs
>   . type some common han character, which will be displayed by a font
>     that supports the common han characters
>   . type some rare han character, such as U+2F75, not supported by the
>     font chosen in the previous step
>
> I'm asking whether Emacs will in step 3 search and find a font which
> can display U+2F75, or will it show tofu because it already has a han
> font, and that font doesn't support U+2F75?

In principle, yes, but with the important exception that the font which
supports U+2F75 must also support all of the characters in the entry in
script-representative-chars for han.

> But when Emacs actually needs to display one of those rare characters,
> will Emacs which uses Fontconfig then be able to find a suitable font,
> if it is installed?

The answer is yes, at least subject to the above.