Unexpected empty string returned from ToPunycode

[RBeaudoin]

When I execute the following:

func main() {
 fmt.Println(idn.ToPunycode("❤.rust-lang.org"))
}

It prints the empty string. I would expect the ToPunycode method to return xn--qei.rust-lang.org

[rafaeljusto]

The domain ❤.rust-lang.org did not convert also in the Verisign IDN Tool. I got it converted in Punycoder website. The code point 10084 (U+2764 - ❤) is disallowed in this library due to CURVED STEM PARAGRAPH SIGN ORNAMENT..HEAVY W (reference) and follows RFC 5892 - Appendix B.1.

[RBeaudoin]

Thanks @rafaeljusto

This seems to be a code point that is allowed in some implementations, but not others. The RFC does seem to clearly indicate that it is not allowed.

[miekg]

[ Quoting <notifications@github.com> in "Re: [miekg/dns] Unexpected empty st..." ]

Thanks @rafaeljusto This seems to be a code point that is allowed in some implementations, but not others. The RFC does seem to clearly indicate that it is not allowed.

File an errata! Which would help and might lead to a follow up RFC

[andrewtj]

@RBeaudoin are you satisfied with @rafaeljusto's explanation or would you like to start a conversation about (potentially) adding additional API?

[RBeaudoin]

@andrewtj yes, thank you. At Heroku we had to switch to another library because Let's Encrypt supports issuing certs for emoji domains, and we do pre-validation.

I completely understand it's not in the spec though, and appreciate the explanation.

[miekg]

#584 (removes our implementation of idn)