ded");
  assert_equals(openedWindow.history.length, 1,
    "history.length should not increase after normal navigation away from initial empty document");

  // Navigate again using the same method, but this time it shouldn't do a
  // replacement since it's no longer on the initial empty document.
  openedWindow.open(url2, "_self");
  await waitForMessage(t, "loaded");
  assert_equals(openedWindow.history.length, 2,
    "history.length should increase after normal navigation away from non-initial empty doc