host returns Host::Domain with custom protocols even though it is an IP address

[tbu-]

This should at least be documented as a pitfall.

use url::Url;
fn main() {
    println!("{:?}", Url::parse("http://127.0.0.1").unwrap().host());
    println!("{:?}", Url::parse("custom://127.0.0.1").unwrap().host());
}

$ cargo run
[…]
Some(Ipv4(127.0.0.1))
Some(Domain("127.0.0.1"))

[lufte]

This is probably a duplicate of #606 in which it is explained that this is part of the URL standard.

I also created #763 to request a compile-time setting for including more schemes to this standard list of "special" schemes that have this behavior. In the meantime I forked the library and hardcoded the schemes I needed myself, maybe this works for you too: master...lufte:rust-url:gemini

[tmccombs]

Given how often something like this comes up. It might be worth at least adding something to the crate documentation to warn that the behavior is different for "special" schemes, and why that is.