<!DOCTYPE html>
<head>
  <title>Deferred loading=lazy iframes load relative to the document's base URL
         at parse-time</title>
  <link rel="author" title="Dom Farolino" href="mailto:dom@chromium.org">
  <link rel="author" title="Raj T" href="mailto:rajendrant@chromium.org">
  <script src="/resources/testharness.js"></script>
  <script src="/resources/testharnessreport.js"></script>
  <script src="../resources/common.js"></script>
</head>

<script>
  const below_viewport_iframe = new ElementLoadPromise("below-viewport");

  let has_window_loaded = false;

  async_test(t => {
    // Change the document's base URL to a bogus one, and scroll the
    // below-viewport iframe into view. When it loads, it should load relative
    // to the old base URL computed at parse-time.
    window.addEventListener("load", t.step_func(() => {
      window.history.pushState(2, document.title,
                               '/invalid-url-where-no-subresources-exist/')
      has_window_loaded = true;
      below_viewport_iframe.element().scrollIntoView();
    }));

    below_viewport_iframe.promise.then(t.step_func_done(() => {
      assert_true(has_window_loaded,
            "Below-viewport loading=lazy iframes do not block the " +
            "window load event");
      assert_true(below_viewport_iframe.element()
                    .contentDocument.body.innerHTML.includes("<p>Subframe</p>"));
    }));

  }, "When a loading=lazy iframe is loaded, it loads relative to the " +
     "document's base URL computed at parse-time.");
</script>

<body>
  <div style="height:1000vh;"></div>
  <script>
    // Change the document's base URL so that the iframe request parses relative
    // to it when it sets up the request at parse-time.
    window.history.pushState(1, document.title, 'resources/')
  </script>
  <iframe id="below-viewport" src="subframe.html" loading="lazy" width="200px"
          height="100px" onload="below_viewport_iframe.resolve()"</iframe>
</body>
