<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
promise_test(async t => {
  // Wait for after the load event so that the navigation doesn't get converted
  // into a replace navigation.
  await new Promise(resolve => window.onload = () => t.step_timeout(resolve, 0));
  location.hash = "#1";
  location.hash = "#2";
  history.go(-2);
  await new Promise(r => window.onpopstate = r);

  // Traverse forward then immediately do a same-document push. This will
  // truncate the back forward list.
  history.forward();
  location.hash = "#clobber";

  // history.forward() should be aborted.
  window.onpopstate = t.unreached_func("history.forward() should have been cancelled");
  await new Promise(r => t.step_timeout(r, 20));
  assert_equals(location.hash, "#clobber");
}, "If forward pruning clobbers the target of a traverse, abort");
</script>
