message: Fix Ensure we don't write 0 bytes to pty
  Any action that results in 0 bytes, such as pasting 0 bytes
  from the clipboard hangs the terminal (`pbcopy </dev/null`
  followed by ctrl-v), hangs the terminal on both macOS and
  Linux. This ensures we never send 0 bytes.
diff: @@ -60,6 +60,10 @@ impl event::Notify for Notifier {
  where B: Into<Cow<'static, [u8]>>
  {
  let bytes = bytes.into();
  + // terminal hangs if we send 0 bytes through.
  + if bytes.len() == 0 {
  + return
  + }
  match self.0.send(Msg::Input(bytes)) {
  Ok(_) => (),
  Err(_) => panic!("expected send event loop msg"),
  