bug#51733: 27.1; Detect impossible email addresses better

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> I don't think I understand what you mean by "the Asian parts".  Do you
> mean the CJK parts where we lump several scripts together into 'han'
> and 'kana'?

Possibly -- I haven't looked closely.

>> It's impossible to implement the Unicode security recommendations based
>> on the Blocks.txt data -- it's that simple.
>
> Can you tell more about why it is impossible?  If it's a relatively
> simple issue of "translating" the Unicode script names into ours, then
> it should be quite simple.  Since you say it's impossible, I guess
> there's some factor(s) here that I miss?

Perhaps there's something I'm missing, because it seems self-evident to
me that the Blocks data can't be used for this.

For instance,

(textsec-single-script-p "ޱ﷽")
=> t

but

(elt char-script-table ?ޱ)
=> thaana

(elt char-script-table ?﷽)
=> arabic

I think the Unicode people have the authoritative say here, so
implementing the recommendations seems like the way to go.  And it's
less work in the long run, because we can just import the data files and
not try to fix things up manually (like blocks.awk attempts to do).

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no