bug#64420: string-width of … is 2 in CJK environments

[Dmitry Gutov]

On 05/08/2023 18:01, Eli Zaretskii wrote:
> OK, this is now installed on master.  We have a new user option named
> cjk-ambiguous-chars-are-wide; its default is t, but if set to nil, the
> characters proclaimed by Unicode as "ambiguous" will have char-width
> of 1, not 2.  Note that this option should be set either via 'setopt'
> or the Customize interface, not via 'setq'.
>
> Let me know how well this works for you.

Seems to work fine, thank you.

With the caveat that, in the terminal, if I switch to Chinese-BIG5 and 
visit a file with ambiguous characters like … (which triggers some bugs 
with display and navigation around those chars), (setopt 
cjk-ambiguous-chars-are-wide nil) doesn't fix those bugs -- I have to 
kill and re-visit the buffer for them to go away. But maybe that's expected.

In GUI everything's fine, the 'setopt' call makes things better right away.