[cosmo-dev] More Unicode

[Jared Rhine]

> All that said, I think I'm leaning toward favoring the following:
>
> 1) Restrict usernames to U+0000-U+FFFF server side, add client side  
> logic to explain and enforce restriction
> 2) Create 1.0 bug to handle U+10000 and above characters in data  
> correctly.

I have no Hub product or operational reason to support usernames  
outside the BMP.  I support refusing to create such usernames server- 
side, and restricting their submission in the UI.

I don't think we should work to support astral Unicode planes  
anywhere, even in payloads.  The payoff is very low.  If checking for  
astral codepoints is cheap, it'd be cool to throw an error upon  
submission, but I bet we would live fine even if we didn't do that.

I'm fine with a U+10000 bug for future, but I would really prefer to  
see it Futured and *not* 1.0.  1.0 is too close, and has other far  
more valuable goals.

-- Jared