use std::{borrow::Cow, convert::Infallible}; pub use bstr;use bstr::{BStr, BString, ByteSlice}; use crate::Scheme; /// The Error returned by [`parse()`]#[derive(Debug, thiserror::Error)]#[allow(missing_docs)]pub enum Error {    #[error("Could not decode URL as UTF8")]    Utf8(#[from] std::str::Utf8Error),    #[error(transparent)]    Url(#[from] url::ParseError),    #[error("urls require the path to the repository")]    MissingResourceLocation,    #[error("file urls require an absolute or relative path to the repository repository")]    MissingRepositoryPath,    #[error("\"{url}\" is not a valid local path")]    NotALocalFile { url: BString },    #[error("Relative URLs are not permitted: {url:?}")]    RelativeUrl { url: String },} impl From<Infallible> for Error {    fn from(_: Infallible) -> Self {        unreachable!("Cannot actually happen, but it seems there can't be a blanket impl for this")    }} fn str_to_protocol(s: &str) -> Scheme {    Scheme::from(s)} fn guess_protocol(url: &[u8]) -> Option<&str> {    match url.find_byte(b':') {        Some(colon_pos) => {            if url[..colon_pos].find_byte(b'.').is_some() {                "ssh"            } else {                url.get(colon_pos + 1..).and_then(|from_colon| {                    (from_colon.contains(&b'/') || from_colon.contains(&b'\\')).then(|| "file")                })?            }        }        None => "file",    }    .into()} /// Extract the path part from an SCP-like URL `[user@]host.xz:path/to/repo.git/`fn extract_scp_path(url: &str) -> Option<&str> {    url.splitn(2, ':').last()} fn sanitize_for_protocol<'a>(protocol: &str, url: &'a str) -> Cow<'a, str> {    match protocol {        "ssh" => url.replacen(':', "/", 1).into(),        _ => url.into(),    }} fn has_no_explicit_protocol(url: &[u8]) -> bool {    url.find(b"://").is_none()} fn to_owned_url(url: url::Url) -> Result<crate::Url, Error> {    Ok(crate::Url {        serialize_alternative_form: false,        scheme: str_to_protocol(url.scheme()),        user: if url.username().is_empty() {            None        } else {            Some(url.username().into())        },        host: url.host_str().map(Into::into),        port: url.port(),        path: url.path().into(),    })} /// Parse the given `bytes` as git url.////// # Note////// We cannot and should never have to deal with UTF-16 encoded windows strings, so bytes input is acceptable./// For file-paths, we don't expect UTF8 encoding either.pub fn parse(input: &BStr) -> Result<crate::Url, Error> {    let guessed_protocol = guess_protocol(input).ok_or_else(|| Error::NotALocalFile { url: input.into() })?;    let path_without_file_protocol = input.strip_prefix(b"file://");    if path_without_file_protocol.is_some() || (has_no_explicit_protocol(input) && guessed_protocol == "file") {        let path: BString = path_without_file_protocol            .map(|stripped_path| {                #[cfg(windows)]                {                    if stripped_path.starts_with(b"/") {                        input                            .to_str()                            .ok()                            .and_then(|url| {                                let path = url::Url::parse(url).ok()?.to_file_path().ok()?;                                path.is_absolute().then(|| git_path::into_bstr(path).into_owned())                            })                            .unwrap_or_else(|| stripped_path.into())                    } else {                        stripped_path.into()                    }                }                #[cfg(not(windows))]                {                    stripped_path.into()                }            })            .unwrap_or_else(|| input.into());        if path.is_empty() {            return Err(Error::MissingRepositoryPath);        }        let input_starts_with_file_protocol = input.starts_with(b"file://");        if input_starts_with_file_protocol {            let wanted = cfg!(windows).then(|| &[b'\\', b'/'] as &[_]).unwrap_or(&[b'/']);            if !wanted.iter().any(|w| path.contains(w)) {                return Err(Error::MissingRepositoryPath);            }        }        return Ok(crate::Url {            scheme: Scheme::File,            path,            serialize_alternative_form: !input_starts_with_file_protocol,            ..Default::default()        });    }     let url_str = std::str::from_utf8(input)?;    let (mut url, mut scp_path) = match url::Url::parse(url_str) {        Ok(url) => (url, None),        Err(url::ParseError::RelativeUrlWithoutBase) => {            // happens with bare paths as well as scp like paths. The latter contain a ':' past the host portion,            // which we are trying to detect.            (                url::Url::parse(&format!(                    "{}://{}",                    guessed_protocol,                    sanitize_for_protocol(guessed_protocol, url_str)                ))?,                extract_scp_path(url_str),            )        }        Err(err) => return Err(err.into()),    };    // SCP like URLs without user parse as 'something' with the scheme being the 'host'. Hosts always have dots.    if url.scheme().find('.').is_some() {        // try again with prefixed protocol        url = url::Url::parse(&format!("ssh://{}", sanitize_for_protocol("ssh", url_str)))?;        scp_path = extract_scp_path(url_str);    }    if url.path().is_empty() && ["ssh", "git"].contains(&url.scheme()) {        return Err(Error::MissingResourceLocation);    }    if url.cannot_be_a_base() {        return Err(Error::RelativeUrl { url: url.into() });    }     let mut url = to_owned_url(url)?;    if let Some(path) = scp_path {        url.path = path.into();        url.serialize_alternative_form = true;    }    Ok(url)}