Bug 1170226 - Restore correct shistory index when setting up pending tabs r=billm

browser/components/sessionstore/ContentRestore.jsm

@@ -193,11 +193,6 @@ ContentRestoreInternal.prototype = {
       if (loadArguments) {
         // A load has been redirected to a new process so get history into the
         // same state it was before the load started then trigger the load.
-        let activeIndex = tabData.index - 1;
-        if (activeIndex > 0) {
-          // Go to the right history entry, but don't load anything yet.
-          history.getEntryAtIndex(activeIndex, true);
-        }
         let referrer = loadArguments.referrer ?
                        Utils.makeURI(loadArguments.referrer) : null;
         let referrerPolicy = ('referrerPolicy' in loadArguments
@@ -210,12 +205,6 @@ ContentRestoreInternal.prototype = {
         // If the user typed a URL into the URL bar and hit enter right before
         // we crashed, we want to start loading that page again. A non-zero
         // userTypedClear value means that the load had started.
-        let activeIndex = tabData.index - 1;
-        if (activeIndex > 0) {
-          // Go to the right history entry, but don't load anything yet.
-          history.getEntryAtIndex(activeIndex, true);
-        }
-
         // Load userTypedValue and fix up the URL if it's partial/broken.
         webNavigation.loadURI(tabData.userTypedValue,
                               Ci.nsIWebNavigation.LOAD_FLAGS_ALLOW_THIRD_PARTY_FIXUP,
@@ -231,7 +220,6 @@ ContentRestoreInternal.prototype = {
         // In order to work around certain issues in session history, we need to
         // force session history to update its internal index and call reload
         // instead of gotoIndex. See bug 597315.
-        history.getEntryAtIndex(activeIndex, true);
         history.reloadCurrentEntry();
       } else {
         // If there's nothing to restore, we should still blank the page.

browser/components/sessionstore/SessionHistory.jsm

@@ -265,6 +265,12 @@ let SessionHistoryInternal = {
       let persist = "persist" in entry ? entry.persist : true;
       history.addEntry(this.deserializeEntry(entry, idMap, docIdentMap), persist);
     }
+
+    // Select the right history entry.
+    let index = tabData.index - 1;
+    if (index < history.count && history.index != index) {
+      history.getEntryAtIndex(index, true);
+    }
   },
 
   /**

browser/components/sessionstore/test/browser.ini

@@ -94,6 +94,7 @@ skip-if = buildapp == 'mulet'
 [browser_merge_closed_tabs.js]
 [browser_page_title.js]
 [browser_pageStyle.js]
+[browser_pending_tabs.js]
 [browser_privatetabs.js]
 [browser_replace_load.js]
 [browser_restore_redirect.js]

browser/components/sessionstore/test/browser_pending_tabs.js

@@ -0,0 +1,32 @@
+"use strict";
+
+const TAB_STATE = {
+  entries: [{ url: "about:mozilla" }, { url: "about:robots" }],
+  index: 1,
+};
+
+add_task(function* () {
+  // Create a background tab.
+  let tab = gBrowser.addTab("about:blank");
+  let browser = tab.linkedBrowser;
+  yield promiseBrowserLoaded(browser);
+
+  // The tab shouldn't be restored right away.
+  Services.prefs.setBoolPref("browser.sessionstore.restore_on_demand", true);
+
+  // Prepare the tab state.
+  let promise = promiseTabRestoring(tab);
+  ss.setTabState(tab, JSON.stringify(TAB_STATE));
+  ok(tab.hasAttribute("pending"), "tab is pending");
+  yield promise;
+
+  // Flush to ensure the parent has all data.
+  yield TabStateFlusher.flush(browser);
+
+  // Check that the shistory index is the one we restored.
+  let tabState = TabState.collect(tab);
+  is(tabState.index, TAB_STATE.index, "correct shistory index");
+
+  // Cleanup.
+  gBrowser.removeTab(tab);
+});