Francisek

idn_to_ascii is related to the intl extension. We could use pure php shim with an external library like https://github.com/phlylabs/idna-convert as the converstion rules are a bit complicated.

A better way would be to url_encode path parts and convert url to punycode. I can pr something like this

IMO as the spec does not explicitly tells if the url can be raw UTF-8 or whatever else, it would be safest to use full encoded urls and have plain...