use std::io; use bstr::{BString, ByteSlice};use quick_error::quick_error; use crate::{encode::SPACE, tree::Entry, Tree}; quick_error! {    /// The Error used in [`Tree::write_to()`].    #[derive(Debug)]    #[allow(missing_docs)]    pub enum Error {        NewlineInFilename(name: BString) {            display("Newlines are invalid in file paths: {:?}", name)        }    }} impl From<Error> for io::Error {    fn from(err: Error) -> Self {        io::Error::new(io::ErrorKind::Other, err)    }} /// Serializationimpl Tree {    /// Serialize this tree to `out` in the git internal format.    pub fn write_to(&self, mut out: impl io::Write) -> io::Result<()> {        debug_assert_eq!(            &{                let mut entries_sorted = self.entries.clone();                entries_sorted.sort();                entries_sorted            },            &self.entries,            "entries for serialization must be sorted by filename"        );        for Entry { mode, filename, oid } in &self.entries {            out.write_all(mode.as_bytes())?;            out.write_all(SPACE)?;             if filename.find_byte(b'\n').is_some() {                return Err(Error::NewlineInFilename(filename.to_owned()).into());            }            out.write_all(filename)?;            out.write_all(&[b'\0'])?;             out.write_all(oid.as_bytes())?;        }        Ok(())    }}