[prettyroseslover]

During fuzz testing I found a bug in path shortening.
Minimal snippet to reproduce:

use url::Url;

fn main() {
    let base_str = "file:eeeeeeeeeeexmlns=\"http://U:";
    let base_url = Url::parse(base_str).unwrap();
    let raw_str = "../../index.html";
    Url::join(&base_url, raw_str).unwrap();
}

Fixed it and added a unit-test