<!doctype html>
<meta charset="utf-8">
<title>history.forward() uses this's associated document's browsing context to determine if navigation is allowed</title>
<link rel="help" href="https://html.spec.whatwg.org/multipage/history.html#dom-history-forward">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<iframe id="sandboxedIframe" srcdoc="hello" sandbox="allow-scripts allow-same-origin"></iframe>
<script>
const t = async_test();

t.step(() => {
  history.pushState({}, null, "?prev");
  history.pushState({}, null, "?current");
  history.back();
});

let isCrossRealmForward = false;
window.onpopstate = t.step_func(() => {
  if (isCrossRealmForward) {
    assert_equals(location.search, "?current");
    t.done();
  } else {
    sandboxedIframe.contentWindow.history.forward.call(history);
    isCrossRealmForward = true;
  }
});
</script>
