Function git_overlay_current_thread_push_ok 

pub fn git_overlay_current_thread_push_ok(
    all_threads: bool,
    requested: Option<&str>,
    attached: Option<&str>,
) -> bool

Whether a git-overlay current-thread refs push may target requested.

Git-overlay refs push always ships the attached HEAD branch. When the user names a different thread without --all-threads, callers should refuse. all_threads == true or requested == None always allows.