Function commits_under

crates/flowtrace-cli/src/git.rs:183–229

Commits whose tree changed `rel_path` (file or directory), newest first. `rel_path` is trace-relative; resolves to repo-relative internally so single-repo and per-trace layouts both work.

(root: &Path, rel_path: &str)

/// `rel_path` is trace-relative; resolves to repo-relative internally so
/// single-repo and per-trace layouts both work.
pub fn commits_under(root: &Path, rel_path: &str) -> Result<Vec<CommitInfo>> {
    let repo = open(root)?;
    let translated = translate(&repo, root, rel_path);
    let mut walk = repo.revwalk()?;
    walk.push_head().context("revwalk push HEAD")?;
    walk.set_sorting(git2::Sort::TIME)?;

    let target_path = Path::new(&translated);
    let mut out = Vec::new();
    for oid in walk {
        let oid = oid?;
        let commit = repo.find_commit(oid)?;
        let commit_tree = commit.tree()?;
        let touched = if commit.parent_count() == 0 {
            tree_contains_path(&commit_tree, target_path)?
        } else {
            let mut found = false;
            for i in 0..commit.parent_count() {
                let parent = commit.parent(i)?;
                let parent_tree = parent.tree()?;
                let diff = repo.diff_tree_to_tree(Some(&parent_tree), Some(&commit_tree), None)?;
                for delta in diff.deltas() {
                    if path_matches(delta.new_file().path(), target_path)
                        || path_matches(delta.old_file().path(), target_path)
                    {
                        found = true;
                        break;
                    }
                }
                if found {
                    break;
                }
            }
            found
        };
        if touched {
            let time = commit.time();
            let at = Utc.timestamp_opt(time.seconds(), 0).single().unwrap_or_else(Utc::now);
            out.push(CommitInfo {
                sha: oid.to_string(),
                at,
                message: commit.message().unwrap_or("").trim_end().to_string(),
            });
        }
    }
    Ok(out)
}

fn path_matches(p: Option<&Path>, target: &Path) -> bool {
    let Some(p) = p else { return false };