Function isKeypressCommand

docs/external/js/react-dom.development.js:8806–8809

* Return whether a native keypress event is assumed to be a command. * This is required because Firefox fires `keypress` events for key commands * (cut, copy, select-all, etc.) even though no character is inserted.

(nativeEvent)

   */

  function isKeypressCommand(nativeEvent) {
    return (nativeEvent.ctrlKey || nativeEvent.altKey || nativeEvent.metaKey) && // ctrlKey && altKey is equivalent to AltGr, and is not a command.
    !(nativeEvent.ctrlKey && nativeEvent.altKey);
  }
  /**
   * Translate native top level events into event types.
   *