use bstr::BStr; use crate::protocol::context::Error; mod write {    use bstr::{BStr, BString};     use crate::protocol::{Context, ContextOptions, context::serde::validate};     impl Context {        /// Write ourselves to `out` such that [`from_bytes()`][Self::from_bytes()] can decode it losslessly.        pub fn write_to(&self, mut out: impl std::io::Write) -> std::io::Result<()> {            use bstr::ByteSlice;            fn write_key(out: &mut impl std::io::Write, key: &str, value: &BStr) -> std::io::Result<()> {                out.write_all(key.as_bytes())?;                out.write_all(b"=")?;                out.write_all(value)?;                out.write_all(b"\n")            }            let Context {                options: ContextOptions { protect_protocol },                protocol,                host,                path,                username,                password,                oauth_refresh_token,                password_expiry_utc,                url,                // We only decode quit and interpret it, but won't get to pass it on as it means to stop the                // credential helper invocation chain.                quit: _,            } = self;            for (key, value) in [("url", url), ("path", path)] {                if let Some(value) = value {                    validate(key, value.as_slice().into(), *protect_protocol).map_err(std::io::Error::other)?;                    write_key(&mut out, key, value.as_ref()).ok();                }            }            for (key, value) in [                ("protocol", protocol),                ("host", host),                ("username", username),                ("password", password),                ("oauth_refresh_token", oauth_refresh_token),            ] {                if let Some(value) = value {                    validate(key, value.as_str().into(), *protect_protocol).map_err(std::io::Error::other)?;                    write_key(&mut out, key, value.as_bytes().as_bstr()).ok();                }            }            if let Some(value) = password_expiry_utc {                let key = "password_expiry_utc";                let value = value.to_string();                validate(key, value.as_str().into(), *protect_protocol).map_err(std::io::Error::other)?;                write_key(&mut out, key, value.as_bytes().as_bstr()).ok();            }            Ok(())        }         /// Like [`write_to()`][Self::write_to()], but writes infallibly into memory.        pub fn to_bstring(&self) -> BString {            let mut buf = Vec::<u8>::new();            self.write_to(&mut buf).expect("infallible");            buf.into()        }    }} ///pub mod decode {    use bstr::{BString, ByteSlice};     use crate::protocol::{Context, ContextOptions, context, context::serde::validate};     /// The error returned by [`from_bytes()`][Context::from_bytes()].    #[derive(Debug, thiserror::Error)]    #[expect(missing_docs)]    pub enum Error {        #[error("Illformed UTF-8 in value of key {key:?}: {value:?}")]        IllformedUtf8InValue { key: String, value: BString },        #[error(transparent)]        Encoding(#[from] context::Error),        #[error("Invalid format in line {line:?}, expecting key=value")]        Syntax { line: BString },    }     impl Context {        /// Decode ourselves from `input` which is the format written by [`write_to()`][Self::write_to()].        /// `options` control what to support during deserialization.        pub fn from_bytes(input: &[u8], options: ContextOptions) -> Result<Self, Error> {            let mut ctx = Context {                options,                ..Context::default()            };            let Context {                options: _,                protocol,                host,                path,                username,                password,                oauth_refresh_token,                password_expiry_utc,                url,                quit,            } = &mut ctx;            for res in input.lines().take_while(|line| !line.is_empty()).map(|line| {                let mut it = line.splitn(2, |b| *b == b'=');                match (                    it.next().and_then(|k| k.to_str().ok()),                    it.next().map(ByteSlice::as_bstr),                ) {                    (Some(key), Some(value)) => validate(key, value, options.protect_protocol)                        .map(|_| (key, value.to_owned()))                        .map_err(Into::into),                    _ => Err(Error::Syntax { line: line.into() }),                }            }) {                let (key, value) = res?;                match key {                    "protocol" | "host" | "username" | "password" | "oauth_refresh_token" => {                        if !value.is_utf8() {                            return Err(Error::IllformedUtf8InValue { key: key.into(), value });                        }                        let value = value.to_string();                        *match key {                            "protocol" => &mut *protocol,                            "host" => host,                            "username" => username,                            "password" => password,                            "oauth_refresh_token" => oauth_refresh_token,                            _ => unreachable!("checked field names in match above"),                        } = Some(value);                    }                    "password_expiry_utc" => {                        *password_expiry_utc = value.to_str().ok().and_then(|value| value.parse().ok());                    }                    "url" => *url = Some(value),                    "path" => *path = Some(value),                    "quit" => {                        *quit = gix_config_value::Boolean::try_from(value.as_bstr())                            .ok()                            .map(Into::into);                    }                    _ => {}                }            }            Ok(ctx)        }    }} fn validate(key: &str, value: &BStr, protect_protocol: bool) -> Result<(), Error> {    if key.contains('\0')        || key.contains('\n')        || key.contains('\r')        || value.contains(&0)        || value.contains(&b'\n')        || (protect_protocol && value.contains(&b'\r'))    {        return Err(Error::Encoding {            key: key.to_owned(),            value: value.to_owned(),        });    }    Ok(())}