Function submodule_active_pathspec_match 

pub fn submodule_active_pathspec_match(
    index: &Index,
    specs: &[String],
    path: &str,
) -> Result<bool, String>

Whether path matches submodule.active pathspecs using the given index (Git match_pathspec).

On missing string values (bare submodule.active), returns an error message suitable for stderr.