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<html lang="en">
  <head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8">
    <title>Bug 1300461</title>
  </head>
  <body onload="test();">
    <script>
      /**
       * Bug 1300461 identifies that if a history entry was not bfcached, and
       * a http redirection happens when navigating to that entry, the history
       * index would mess up.
       *
       * The test case emulates the circumstance by the following steps
       * 1) Navigate to file_bug1300461_back.html which is not bf-cachable.
       * 2) In file_bug1300461_back.html, replace its own history state to
       *    file_bug1300461_redirect.html.
       * 3) Back, and then forward. Since the document is not in bfcache, it
       *    tries to load file_bug1300461_redirect.html directly.
       * 4) file_bug1300461_redirect.html redirects UA to
       *    file_bug1300461_back.html through HTTP 301 header.
       *
       * We verify the history index, canGoBack, canGoForward, etc. keep correct
       * in this process.
       */
      let Ci = SpecialPowers.Ci;
      let webNav = SpecialPowers.wrap(window)
                     .docShell
                     .QueryInterface(Ci.nsIWebNavigation);
      let shistory = webNav.sessionHistory;
      let testSteps = [
        function() {
          opener.is(shistory.count, 1, "check history length");
          opener.is(shistory.index, 0, "check history index");
          opener.ok(!webNav.canGoForward, "check canGoForward");
          setTimeout(() => window.location = "file_bug1300461_back.html", 0);
        },
        function() {
          opener.is(shistory.count, 2, "check history length");
          opener.is(shistory.index, 0, "check history index");
          opener.ok(webNav.canGoForward, "check canGoForward");
          window.history.forward();
        },
        function() {
          opener.is(shistory.count, 2, "check history length");
          opener.is(shistory.index, 0, "check history index");
          opener.ok(webNav.canGoForward, "check canGoForward");
          opener.info("file_bug1300461.html tests finished");
          opener.finishTest();
        },
      ];

      function test() {
        if (opener) {
          opener.info("file_bug1300461.html test " + opener.testCount);
          testSteps[opener.testCount++]();
        }
      }
    </script>
  </body>
</html>
