pub fn show_file_at(
dir: &Path,
revision: &str,
rel_path: &str,
) -> Option<String>Expand description
rel_path’s content at revision (git show <revision>:<rel_path>, e.g.
Git → Open File at Revision…). None when revision doesn’t resolve,
the path isn’t in that tree, or revision fails the same validation
checkout applies to a ref name.