rhg: make output of `files` relative to the current directory and the root

This matches the behavior of `hg files`.
The util is added in `hg-core` instead of `rhg` because this operation could
be useful for other external tools. (this was definitely not prompted by rust
issue  #50784, I swear)

Differential Revision: https://phab.mercurial-scm.org/D8872

rust/hg-core/src/operations/list_tracked_files.rs

@@ -1,85 +1,94 b''
 // list_tracked_files.rs
 //
 // Copyright 2020 Antoine Cezar <[e-mail]>
 //
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
 
 use super::find_root;
 use crate::dirstate::parsers::parse_dirstate;
 use crate::utils::hg_path::HgPath;
 use crate::{DirstateParseError, EntryState};
 use rayon::prelude::*;
 use std::convert::From;
 use std::fmt;
 use std::fs;
 use std::io;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 /// Kind of error encoutered by ListTrackedFiles
 #[derive(Debug)]
 pub enum ListTrackedFilesErrorKind {
     ParseError(DirstateParseError),
 }
 
 /// A ListTrackedFiles error
 #[derive(Debug)]
 pub struct ListTrackedFilesError {
     /// Kind of error encoutered by ListTrackedFiles
     pub kind: ListTrackedFilesErrorKind,
 }
 
 impl std::error::Error for ListTrackedFilesError {}
 
 impl fmt::Display for ListTrackedFilesError {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
         unimplemented!()
     }
 }
 
 impl From<ListTrackedFilesErrorKind> for ListTrackedFilesError {
     fn from(kind: ListTrackedFilesErrorKind) -> Self {
         ListTrackedFilesError { kind }
     }
 }
 
 /// List files under Mercurial control in the working directory
 pub struct ListTrackedFiles {
     root: PathBuf,
 }
 
 impl ListTrackedFiles {
     pub fn new() -> Result<Self, find_root::FindRootError> {
         let root = find_root::FindRoot::new().run()?;
         Ok(ListTrackedFiles { root })
     }
 
     /// Load the tracked files data from disk
     pub fn load(&self) -> Result<ListDirstateTrackedFiles, io::Error> {
         let dirstate = &self.root.join(".hg/dirstate");
         let content = fs::read(&dirstate)?;
         Ok(ListDirstateTrackedFiles { content })
     }
+
+    /// Returns the repository root directory
+    /// TODO I think this is a crutch that creates a dependency that should not
+    /// be there. Operations that need the root of the repository should get
+    /// it themselves, probably in a lazy fashion. But this would make the
+    /// current series even larger, so this is simplified for now.
+    pub fn get_root(&self) -> &Path {
+        &self.root
+    }
 }
 
 /// List files under Mercurial control in the working directory
 /// by reading the dirstate
 pub struct ListDirstateTrackedFiles {
     content: Vec<u8>,
 }
 
 impl ListDirstateTrackedFiles {
     pub fn run(&self) -> Result<Vec<&HgPath>, ListTrackedFilesError> {
         let (_, entries, _) = parse_dirstate(&self.content)
             .map_err(ListTrackedFilesErrorKind::ParseError)?;
         let mut files: Vec<&HgPath> = entries
             .into_iter()
             .filter_map(|(path, entry)| match entry.state {
                 EntryState::Removed => None,
                 _ => Some(path),
             })
             .collect();
         files.par_sort_unstable();
         Ok(files)
     }
 }

rust/hg-core/src/utils/files.rs

@@ -1,382 +1,442 b''
 // files.rs
 //
 // Copyright 2019
 // Raphaël Gomès <[e-mail]>,
 // Yuya Nishihara <[e-mail]>
 //
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
 
 //! Functions for fiddling with files.
 
 use crate::utils::{
     hg_path::{path_to_hg_path_buf, HgPath, HgPathBuf, HgPathError},
     path_auditor::PathAuditor,
     replace_slice,
 };
 use lazy_static::lazy_static;
 use same_file::is_same_file;
-use std::borrow::ToOwned;
+use std::borrow::{Cow, ToOwned};
 use std::fs::Metadata;
 use std::iter::FusedIterator;
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
 
 pub fn get_path_from_bytes(bytes: &[u8]) -> &Path {
     let os_str;
     #[cfg(unix)]
     {
         use std::os::unix::ffi::OsStrExt;
         os_str = std::ffi::OsStr::from_bytes(bytes);
     }
     // TODO Handle other platforms
     // TODO: convert from WTF8 to Windows MBCS (ANSI encoding).
     // Perhaps, the return type would have to be Result<PathBuf>.
 
     Path::new(os_str)
 }
 
 // TODO: need to convert from WTF8 to MBCS bytes on Windows.
 // that's why Vec<u8> is returned.
 #[cfg(unix)]
 pub fn get_bytes_from_path(path: impl AsRef<Path>) -> Vec<u8> {
     use std::os::unix::ffi::OsStrExt;
     path.as_ref().as_os_str().as_bytes().to_vec()
 }
 
 /// An iterator over repository path yielding itself and its ancestors.
 #[derive(Copy, Clone, Debug)]
 pub struct Ancestors<'a> {
     next: Option<&'a HgPath>,
 }
 
 impl<'a> Iterator for Ancestors<'a> {
     type Item = &'a HgPath;
 
     fn next(&mut self) -> Option<Self::Item> {
         let next = self.next;
         self.next = match self.next {
             Some(s) if s.is_empty() => None,
             Some(s) => {
                 let p = s.bytes().rposition(|c| *c == b'/').unwrap_or(0);
                 Some(HgPath::new(&s.as_bytes()[..p]))
             }
             None => None,
         };
         next
     }
 }
 
 impl<'a> FusedIterator for Ancestors<'a> {}
 
 /// An iterator over repository path yielding itself and its ancestors.
 #[derive(Copy, Clone, Debug)]
 pub(crate) struct AncestorsWithBase<'a> {
     next: Option<(&'a HgPath, &'a HgPath)>,
 }
 
 impl<'a> Iterator for AncestorsWithBase<'a> {
     type Item = (&'a HgPath, &'a HgPath);
 
     fn next(&mut self) -> Option<Self::Item> {
         let next = self.next;
         self.next = match self.next {
             Some((s, _)) if s.is_empty() => None,
             Some((s, _)) => Some(s.split_filename()),
             None => None,
         };
         next
     }
 }
 
 impl<'a> FusedIterator for AncestorsWithBase<'a> {}
 
 /// Returns an iterator yielding ancestor directories of the given repository
 /// path.
 ///
 /// The path is separated by '/', and must not start with '/'.
 ///
 /// The path itself isn't included unless it is b"" (meaning the root
 /// directory.)
 pub fn find_dirs(path: &HgPath) -> Ancestors {
     let mut dirs = Ancestors { next: Some(path) };
     if !path.is_empty() {
         dirs.next(); // skip itself
     }
     dirs
 }
 
 /// Returns an iterator yielding ancestor directories of the given repository
 /// path.
 ///
 /// The path is separated by '/', and must not start with '/'.
 ///
 /// The path itself isn't included unless it is b"" (meaning the root
 /// directory.)
 pub(crate) fn find_dirs_with_base(path: &HgPath) -> AncestorsWithBase {
     let mut dirs = AncestorsWithBase {
         next: Some((path, HgPath::new(b""))),
     };
     if !path.is_empty() {
         dirs.next(); // skip itself
     }
     dirs
 }
 
 /// TODO more than ASCII?
 pub fn normalize_case(path: &HgPath) -> HgPathBuf {
     #[cfg(windows)] // NTFS compares via upper()
     return path.to_ascii_uppercase();
     #[cfg(unix)]
     path.to_ascii_lowercase()
 }
 
 lazy_static! {
     static ref IGNORED_CHARS: Vec<Vec<u8>> = {
         [
             0x200c, 0x200d, 0x200e, 0x200f, 0x202a, 0x202b, 0x202c, 0x202d,
             0x202e, 0x206a, 0x206b, 0x206c, 0x206d, 0x206e, 0x206f, 0xfeff,
         ]
         .iter()
         .map(|code| {
             std::char::from_u32(*code)
                 .unwrap()
                 .encode_utf8(&mut [0; 3])
                 .bytes()
                 .collect()
         })
         .collect()
     };
 }
 
 fn hfs_ignore_clean(bytes: &[u8]) -> Vec<u8> {
     let mut buf = bytes.to_owned();
     let needs_escaping = bytes.iter().any(|b| *b == b'\xe2' || *b == b'\xef');
     if needs_escaping {
         for forbidden in IGNORED_CHARS.iter() {
             replace_slice(&mut buf, forbidden, &[])
         }
         buf
     } else {
         buf
     }
 }
 
 pub fn lower_clean(bytes: &[u8]) -> Vec<u8> {
     hfs_ignore_clean(&bytes.to_ascii_lowercase())
 }
 
 #[derive(Eq, PartialEq, Ord, PartialOrd, Copy, Clone)]
 pub struct HgMetadata {
     pub st_dev: u64,
     pub st_mode: u32,
     pub st_nlink: u64,
     pub st_size: u64,
     pub st_mtime: i64,
     pub st_ctime: i64,
 }
 
 // TODO support other plaforms
 #[cfg(unix)]
 impl HgMetadata {
     pub fn from_metadata(metadata: Metadata) -> Self {
         use std::os::unix::fs::MetadataExt;
         Self {
             st_dev: metadata.dev(),
             st_mode: metadata.mode(),
             st_nlink: metadata.nlink(),
             st_size: metadata.size(),
             st_mtime: metadata.mtime(),
             st_ctime: metadata.ctime(),
         }
     }
 }
 
 /// Returns the canonical path of `name`, given `cwd` and `root`
 pub fn canonical_path(
     root: impl AsRef<Path>,
     cwd: impl AsRef<Path>,
     name: impl AsRef<Path>,
 ) -> Result<PathBuf, HgPathError> {
     // TODO add missing normalization for other platforms
     let root = root.as_ref();
     let cwd = cwd.as_ref();
     let name = name.as_ref();
 
     let name = if !name.is_absolute() {
         root.join(&cwd).join(&name)
     } else {
         name.to_owned()
     };
     let auditor = PathAuditor::new(&root);
     if name != root && name.starts_with(&root) {
         let name = name.strip_prefix(&root).unwrap();
         auditor.audit_path(path_to_hg_path_buf(name)?)?;
         Ok(name.to_owned())
     } else if name == root {
         Ok("".into())
     } else {
         // Determine whether `name' is in the hierarchy at or beneath `root',
         // by iterating name=name.parent() until it returns `None` (can't
         // check name == '/', because that doesn't work on windows).
         let mut name = name.deref();
         let original_name = name.to_owned();
         loop {
             let same = is_same_file(&name, &root).unwrap_or(false);
             if same {
                 if name == original_name {
                     // `name` was actually the same as root (maybe a symlink)
                     return Ok("".into());
                 }
                 // `name` is a symlink to root, so `original_name` is under
                 // root
                 let rel_path = original_name.strip_prefix(&name).unwrap();
                 auditor.audit_path(path_to_hg_path_buf(&rel_path)?)?;
                 return Ok(rel_path.to_owned());
             }
             name = match name.parent() {
                 None => break,
                 Some(p) => p,
             };
         }
         // TODO hint to the user about using --cwd
         // Bubble up the responsibility to Python for now
         Err(HgPathError::NotUnderRoot {
             path: original_name.to_owned(),
             root: root.to_owned(),
         })
     }
 }
 
+/// Returns the representation of the path relative to the current working
+/// directory for display purposes.
+///
+/// `cwd` is a `HgPath`, so it is considered relative to the root directory
+/// of the repository.
+///
+/// # Examples
+///
+/// ```
+/// use hg::utils::hg_path::HgPath;
+/// use hg::utils::files::relativize_path;
+/// use std::borrow::Cow;
+///
+/// let file = HgPath::new(b"nested/file");
+/// let cwd = HgPath::new(b"");
+/// assert_eq!(relativize_path(file, cwd), Cow::Borrowed(b"nested/file"));
+///
+/// let cwd = HgPath::new(b"nested");
+/// assert_eq!(relativize_path(file, cwd), Cow::Borrowed(b"file"));
+///
+/// let cwd = HgPath::new(b"other");
+/// assert_eq!(relativize_path(file, cwd), Cow::Borrowed(b"../nested/file"));
+/// ```
+pub fn relativize_path(path: &HgPath, cwd: impl AsRef<HgPath>) -> Cow<[u8]> {
+    if cwd.as_ref().is_empty() {
+        Cow::Borrowed(path.as_bytes())
+    } else {
+        let mut res: Vec<u8> = Vec::new();
+        let mut path_iter = path.as_bytes().split(|b| *b == b'/').peekable();
+        let mut cwd_iter =
+            cwd.as_ref().as_bytes().split(|b| *b == b'/').peekable();
+        loop {
+            match (path_iter.peek(), cwd_iter.peek()) {
+                (Some(a), Some(b)) if a == b => (),
+                _ => break,
+            }
+            path_iter.next();
+            cwd_iter.next();
+        }
+        let mut need_sep = false;
+        for _ in cwd_iter {
+            if need_sep {
+                res.extend(b"/")
+            } else {
+                need_sep = true
+            };
+            res.extend(b"..");
+        }
+        for c in path_iter {
+            if need_sep {
+                res.extend(b"/")
+            } else {
+                need_sep = true
+            };
+            res.extend(c);
+        }
+        Cow::Owned(res)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
     use pretty_assertions::assert_eq;
 
     #[test]
     fn find_dirs_some() {
         let mut dirs = super::find_dirs(HgPath::new(b"foo/bar/baz"));
         assert_eq!(dirs.next(), Some(HgPath::new(b"foo/bar")));
         assert_eq!(dirs.next(), Some(HgPath::new(b"foo")));
         assert_eq!(dirs.next(), Some(HgPath::new(b"")));
         assert_eq!(dirs.next(), None);
         assert_eq!(dirs.next(), None);
     }
 
     #[test]
     fn find_dirs_empty() {
         // looks weird, but mercurial.pathutil.finddirs(b"") yields b""
         let mut dirs = super::find_dirs(HgPath::new(b""));
         assert_eq!(dirs.next(), Some(HgPath::new(b"")));
         assert_eq!(dirs.next(), None);
         assert_eq!(dirs.next(), None);
     }
 
     #[test]
     fn test_find_dirs_with_base_some() {
         let mut dirs = super::find_dirs_with_base(HgPath::new(b"foo/bar/baz"));
         assert_eq!(
             dirs.next(),
             Some((HgPath::new(b"foo/bar"), HgPath::new(b"baz")))
         );
         assert_eq!(
             dirs.next(),
             Some((HgPath::new(b"foo"), HgPath::new(b"bar")))
         );
         assert_eq!(dirs.next(), Some((HgPath::new(b""), HgPath::new(b"foo"))));
         assert_eq!(dirs.next(), None);
         assert_eq!(dirs.next(), None);
     }
 
     #[test]
     fn test_find_dirs_with_base_empty() {
         let mut dirs = super::find_dirs_with_base(HgPath::new(b""));
         assert_eq!(dirs.next(), Some((HgPath::new(b""), HgPath::new(b""))));
         assert_eq!(dirs.next(), None);
         assert_eq!(dirs.next(), None);
     }
 
     #[test]
     fn test_canonical_path() {
         let root = Path::new("/repo");
         let cwd = Path::new("/dir");
         let name = Path::new("filename");
         assert_eq!(
             canonical_path(root, cwd, name),
             Err(HgPathError::NotUnderRoot {
                 path: PathBuf::from("/dir/filename"),
                 root: root.to_path_buf()
             })
         );
 
         let root = Path::new("/repo");
         let cwd = Path::new("/");
         let name = Path::new("filename");
         assert_eq!(
             canonical_path(root, cwd, name),
             Err(HgPathError::NotUnderRoot {
                 path: PathBuf::from("/filename"),
                 root: root.to_path_buf()
             })
         );
 
         let root = Path::new("/repo");
         let cwd = Path::new("/");
         let name = Path::new("repo/filename");
         assert_eq!(
             canonical_path(root, cwd, name),
             Ok(PathBuf::from("filename"))
         );
 
         let root = Path::new("/repo");
         let cwd = Path::new("/repo");
         let name = Path::new("filename");
         assert_eq!(
             canonical_path(root, cwd, name),
             Ok(PathBuf::from("filename"))
         );
 
         let root = Path::new("/repo");
         let cwd = Path::new("/repo/subdir");
         let name = Path::new("filename");
         assert_eq!(
             canonical_path(root, cwd, name),
             Ok(PathBuf::from("subdir/filename"))
         );
     }
 
     #[test]
     fn test_canonical_path_not_rooted() {
         use std::fs::create_dir;
         use tempfile::tempdir;
 
         let base_dir = tempdir().unwrap();
         let base_dir_path = base_dir.path();
         let beneath_repo = base_dir_path.join("a");
         let root = base_dir_path.join("a/b");
         let out_of_repo = base_dir_path.join("c");
         let under_repo_symlink = out_of_repo.join("d");
 
         create_dir(&beneath_repo).unwrap();
         create_dir(&root).unwrap();
 
         // TODO make portable
         std::os::unix::fs::symlink(&root, &out_of_repo).unwrap();
 
         assert_eq!(
             canonical_path(&root, Path::new(""), out_of_repo),
             Ok(PathBuf::from(""))
         );
         assert_eq!(
             canonical_path(&root, Path::new(""), &beneath_repo),
             Err(HgPathError::NotUnderRoot {
                 path: beneath_repo.to_owned(),
                 root: root.to_owned()
             })
         );
         assert_eq!(
             canonical_path(&root, Path::new(""), &under_repo_symlink),
             Ok(PathBuf::from("d"))
         );
     }
 }

rust/rhg/src/commands/files.rs

@@ -1,50 +1,60 b''
 use crate::commands::Command;
 use crate::error::{CommandError, CommandErrorKind};
 use crate::ui::Ui;
 use hg::operations::{ListTrackedFiles, ListTrackedFilesErrorKind};
+use hg::utils::files::{get_bytes_from_path, relativize_path};
+use hg::utils::hg_path::HgPathBuf;
 
 pub const HELP_TEXT: &str = "
 List tracked files.
 
 Returns 0 on success.
 ";
 
 pub struct FilesCommand<'a> {
     ui: &'a Ui,
 }
 
 impl<'a> FilesCommand<'a> {
     pub fn new(ui: &'a Ui) -> Self {
         FilesCommand { ui }
     }
 }
 
 impl<'a> Command<'a> for FilesCommand<'a> {
     fn run(&self) -> Result<(), CommandError> {
         let operation_builder = ListTrackedFiles::new()?;
         let operation = operation_builder.load().map_err(|err| {
             CommandErrorKind::Abort(Some(
                 [b"abort: ", err.to_string().as_bytes(), b"\n"]
                     .concat()
                     .to_vec(),
             ))
         })?;
         let files = operation.run().map_err(|err| match err.kind {
             ListTrackedFilesErrorKind::ParseError(_) => {
                 CommandErrorKind::Abort(Some(
                     // TODO find a better error message
                     b"abort: parse error\n".to_vec(),
                 ))
             }
         })?;
 
+        let cwd = std::env::current_dir()
+            .or_else(|e| Err(CommandErrorKind::CurrentDirNotFound(e)))?;
+        let rooted_cwd = cwd
+            .strip_prefix(operation_builder.get_root())
+            .expect("cwd was already checked within the repository");
+        let rooted_cwd = HgPathBuf::from(get_bytes_from_path(rooted_cwd));
+
         let mut stdout = self.ui.stdout_buffer();
+
         for file in files {
-            stdout.write_all(file.as_bytes())?;
+            stdout.write_all(relativize_path(file, &rooted_cwd).as_ref())?;
             stdout.write_all(b"\n")?;
         }
         stdout.flush()?;
 
         Ok(())
     }
 }