`gix_url::Url` `%`-encodes username in scp-like syntax

[yuja]

Current behavior 😯

This code generates the following output:

fn main() {
    let url = gix_url::parse("_git@source.example.tld:org/repo.git".as_ref()).unwrap();
    dbg!(&url);
    println!("{}", url.to_bstring());
}

[src/main.rs:3:5] &url = Url {
    scheme: Ssh,
    user: Some(
        "_git",
    ),
    password: None,
    host: Some(
        "source.example.tld",
    ),
    serialize_alternative_form: true,
    port: None,
    path: "org/repo.git",
}
%5Fgit@source.example.tld:org/repo.git

Expected behavior 🤔

I'm not pretty sure, but Git appears not to decode %5Fgit back to _git.

This problem was originally reported as jj-vcs/jj#6810.

Git behavior

No response

Steps to reproduce 🕹

No response

[ilyagr]

In the linked issue, Yuya also suggested a workaround: ssh://_git@source.example.tld/org/repo.git seems to work already.

[Byron]

Thanks a lot for reporting!

This is a perfect issue for contributing as a unit test should be straightforward to produce, and a fix can't be far then either.
That could also capture the ssh:// as a workaround, just to be sure _ in usernames there is covered and it won't break later.