Re: getaddrinfo chokes at hostnames containing "emoji" characters

[Name Surname <augeus@outlook.com>]

Florian Weimer wrote:
> On 05/16/2018 10:40 AM, Name Surname wrote:
>> Greetings everyone.
>>
>> I recently bought a domain name containing "emoji" characters, as a
>> novelty and in order to do some experiments. I tried getting the IP
>> address associated to it using getaddrinfo, however, it errs and returns
>> "Name or service not known". The same thing happens with any program
>> that uses glibc for name resolution. I understand that emoji domains are
>> not valid according to IDNA2008, however, some ccTLDs sell them, they
>> were supported according to IDNA2003, and web browsers resolve them
>> normally according to IDNA2003 (at least firefox does).
>>
>> Is this a bug or a feature?
> 
> In the near future, glibc will use the system libidn2 library to 
> implement AI_IDN getaddrinfo support.  You will have to convince the 
> libidn2 maintainers to enable Emoji support (by default), but as long as 
> there is no published standard for that at all (perhaps with the 
> exception of Unicode TR46 transitional mode, which is not recommended), 
> this seems difficult.
> 
> Thanks,
> Florian
> 
> .
> 

It seems that, according to the WHATWG URL standard, IDNs should be 
processed as per IDNA2008:

 > Let result be the result of running Unicode ToASCII with
 > domain_name set to domain, UseSTD3ASCIIRules set to beStrict,
 > CheckHyphens set to false,
 > CheckBidi set to true, CheckJoiners set to true,
 > *processing_option set to Nontransitional_Processing*,
 > and VerifyDnsLength set to beStrict.

Source: https://url.spec.whatwg.org/#idna

(Emphasis mine)

If I am understanding the standard correctly, then discussion of this 
matter is moot, as this implies that emoji domains are not even 
considered valid URLs.