Function resolve_diff_arguments 

pub fn resolve_diff_arguments(
    repo: &Repository,
    cwd_prefix: Option<&str>,
    staged: bool,
    unstaged: bool,
    against: Option<&str>,
    positionals: &[String],
    explicit_paths: &[String],
) -> Result<DiffArguments, ResolveDiffArgumentsError>

Parse grit diff flags and positionals into a DiffTarget and pathspecs.

cwd_prefix is the path from the process cwd to the work tree root (from pathdiff); pass None when unknown or in a bare repo.

Errors

Returns ResolveDiffArgumentsError for flag conflicts or unresolvable revisions.