gecko-dev/docshell/test/browser/browser_bug670318.js

/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

/**
 * Test for Bug 670318
 *
 * When LoadEntry() is called on a browser that has multiple duplicate history
 * entries, history.index can end up out of range (>= history.count).
 */

const URL =
  "http://mochi.test:8888/browser/docshell/test/browser/file_bug670318.html";

add_task(async function test() {
  await BrowserTestUtils.withNewTab(
    { gBrowser, url: "about:blank" },
    async function(browser) {
      await ContentTask.spawn(browser, URL, async function(URL) {
        let history = docShell.QueryInterface(Ci.nsIWebNavigation)
          .sessionHistory;
        let count = 0;

        let testDone = {};
        testDone.promise = new Promise(resolve => {
          testDone.resolve = resolve;
        });

        let listener = {
          OnHistoryNewEntry(aNewURI) {
            if (aNewURI.spec == URL && 5 == ++count) {
              addEventListener(
                "load",
                function onLoad() {
                  removeEventListener("load", onLoad, true);

                  Assert.ok(
                    history.index < history.count,
                    "history.index is valid"
                  );
                  testDone.resolve();
                },
                true
              );

              history.legacySHistory.removeSHistoryListener(listener);
              delete content._testListener;
              content.setTimeout(() => {
                content.location.reload();
              }, 0);
            }
          },

          OnHistoryReload: () => true,
          OnHistoryGotoIndex: () => {},
          OnHistoryPurge: () => {},
          OnHistoryReplaceEntry: () => {
            // The initial load of about:blank causes a transient entry to be
            // created, so our first navigation to a real page is a replace
            // instead of a new entry.
            ++count;
          },

          QueryInterface: ChromeUtils.generateQI([
            Ci.nsISHistoryListener,
            Ci.nsISupportsWeakReference,
          ]),
        };

        history.legacySHistory.addSHistoryListener(listener);
        // Since listener implements nsISupportsWeakReference, we are
        // responsible for keeping it alive so that the GC doesn't clear
        // it before the test completes. We do this by anchoring the listener
        // to the content global window, and clearing it just before the test
        // completes.
        content._testListener = listener;
        content.location = URL;

        await testDone.promise;
      });
    }
  );
});