Case insensitivity for public suffix

[kxxt]

When parsing domains(e.g. bbb.aaa.ac.rS with ac.rs public suffix, the results are wrong except the first call. The parsed root is ac.rS instead of aaa.ac.rS)

>> :dep addr
   Compiling psl v2.1.106
   Compiling addr v0.15.6
>> addr::parse_dns_name("aaa.ac.rS").unwrap().root()
Some("ac.rS")
>> addr::parse_dns_name("aaa.ac.rs").unwrap().root()
Some("aaa.ac.rs")

It appears that addr does not take case insensitivity into account.

Relevant link: https://developers.google.com/speed/public-dns/docs/security?csw=1#randomize_case

[kxxt]

Python tldextract could correctly handle it:

In [1]: from tldextract import TLDExtract

In [2]: extract = TLDExtract()

In [3]: extract("aaa.ac.Rs")
Out[3]: ExtractResult(subdomain='', domain='aaa', suffix='ac.Rs', is_private=False)