Re: master bf0aeaa0d7a: Re-enable displaying `han' characters on Android

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Date: Thu, 01 Aug 2024 18:13:03 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Po Lu <luangruo@yahoo.com>
> >> Cc: emacs-devel@gnu.org
> >> Date: Thu, 01 Aug 2024 17:47:54 +0800
> >> 
> >> Eli Zaretskii <eliz@gnu.org> writes:
> >> 
> >> > But users can add a font spec for 'han' to the fontset, cannot they?
> >> > And if they do, then the representative characters _are_ important,
> >> > aren't they?  So I don't think we should remove those characters.
> >> 
> >> Such an action would be pointless, as the fontset would not match any
> >> CJK font actually in existence, and it would break the Android build to
> >> boot.
> >
> > Then Android users should not do that.  But users of other systems
> > could, and we should not prevent them from doing so.
> 
> We don't prevent users from modifying script-representative-chars
> anywhere, no?

We don't prevent users from doing silly things, no.  But they
shouldn't.

> > On my Windows 11 system, I see all of them, and I didn't install any
> > additional fonts for CJK.  So your assertion is simply not true.
> > Maybe your GNU/Linux system is outdated, or maybe GNU/Linux users with
> > CJK interests are supposed to install optional packages that you don't
> > have installed.
> 
> This is an installation of Fedora Workstation 40 that was updated
> yesterday, and where all of the Noto font packages that are required for
> displaying CJK text are undoubtedly installed.  The reason these
> characters are omitted from the suggested set of CJK fonts is that there
> is simply insufficient interest in these characters, and probably the
> same reasonining holds on Android, where users cannot install fonts at
> all, and where the entirety of these pages, save about a dozen, is tofu:
> 
>   https://commons.wikimedia.org/wiki/Category:Unicode_20000-2A6DF_CJK_Unified_Ideographs_Extension_B
>   https://commons.wikimedia.org/wiki/Category:Unicode_2A700-2B73F_CJK_Unified_Ideographs_Extension_C
>   https://commons.wikimedia.org/wiki/Category:Unicode_2B740-2B81F_CJK_Unified_Ideographs_Extension_D
>   https://commons.wikimedia.org/wiki/Category:Unicode_2B820-2CEAF_CJK_Unified_Ideographs_Extension_E
>   https://commons.wikimedia.org/wiki/Category:Unicode_2CEB0-2EBEF_CJK_Unified_Ideographs_Extension_F
> 
> Noto are apparently quite reluctant to support Extension B:
> 
>   https://github.com/notofonts/noto-cjk/issues/13
> 
> and they are the go-to source of Free CJK fonts nowadays.

I'm unconvinced, sorry.  I'll wait a bit for others to chime in,
before I decide what to do with this, but currently I tend to revert
you change to script-representative-chars.