sbool jmenuItem_newThreads;

static JMenuItem jmenuItem(fS text) {
  ret jMenuItem(text, null);
}

static JMenuItem jmenuItem(fS text, fO r) {
  ret swing(func -> JMenuItem {
    Pair<S, Int> p = jmenu_autoMnemonic(dropPrefix("[disabled] ", text));
    JMenuItem mi = new JMenuItem(p.a);
    if (startsWith(text, "[disabled] ")) disableMenuItem(mi);
    if (p.b != 0) mi.setMnemonic(p.b);
    mi.addActionListener(jmenuItem_newThreads
      ? actionListenerInNewThread(r)
      : actionListener(r));
    ret mi;
  });
}

Began life as a copy of #1003661