[colanderman]

I forget the specifics, but there are several incompatibilities between the IETF URI and IRI spec and the WHATWG URL spec (see [1], EDIT: as I'm sure you're well aware, given your username). The WHATWG spec amounts to "what four popular web browsers do", explicitly without considering compatibility with the hundreds (thousands?) of other non-web-browser tools that make use of URIs.

What you've defined are effectively not URLs. Very similar, but different. If you wanted to call them "WHATWGRLs" or something I wouldn't care. But they're not URLs, and the WHATWG is choosing to muddy the waters rather than, say, specify an optional legacy compatibility layer on top of the IETF spec. It's one thing to say "in addition to IETF URIs, browsers should also accept these malformed URIs, but should not accept these valid but problematic URIs"… it's quite another to say "URIs aren't that anymore, now they're this".

[1] https://daniel.haxx.se/blog/2016/05/11/my-url-isnt-your-url/

[annevk]

I'm not sure I get the distinction. As for curl, it doesn't follow any standard which seems worse, but does at least helpfully demonstrate that the RFCs cannot be implemented by major clients.