<!doctype html>
<html>
  <head>
    <title>XMLHttpRequest: open() resolving URLs (about:blank iframe)</title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <link rel="help" href="https://xhr.spec.whatwg.org/#the-open()-method" data-tested-assertations="following::ol/li[2]/ol/li[2] following::ol/li[7] following::ol/li[14]/ul/li[2]" />
    <link rel="help" href="https://xhr.spec.whatwg.org/#the-responsetext-attribute" data-tested-assertat