Comments on IDNA Bidi
Harald Alvestrand
harald at alvestrand.no
Sun Jan 13 04:26:29 CET 2008
Mark Davis skrev:
> Fair enough.
>
> If you assume that a URL is valid IDNAbis(draft) when it is actually
> IDNA2003, you will break if
>
> 1. you assume it is all case folded
> 2. you assume that a non-spacing mark is at the end
> 3. you assume that any of some 3000 characters are not in it
> 4. you assume that ZWJ/NJ is insignificant
> 5. you assume that a trailing combining mark in a label means it is
> not RTL
> 6. you assume that a
>
> and so on.
I see where we misunderstand each other now.
The problem identified in bidi is a backwards compatibility problem
because it's a problem that might happen if someone assumes that a
string is IDNA2003 when it's actually IDNAbis, which is the inverse of
the above.
What you are talking about above is what I'd call a *forward*
compatibility problem.
Harald
More information about the Idna-update
mailing list