Bug 900910 - Initialize SessionStore earlier to catch windows opened immediately after startup. r=ttaubert

browser/components/nsBrowserGlue.js

@@ -472,6 +472,7 @@ BrowserGlue.prototype = {
     ShumwayUtils.init();
     webrtcUI.init();
     AboutHome.init();
+    SessionStore.init();
 
     if (Services.prefs.getBoolPref("browser.tabs.remote"))
       ContentClick.init();
@@ -612,7 +613,6 @@ BrowserGlue.prototype = {
     }
 #endif
 
-    SessionStore.init(aWindow);
     this._trackSlowStartup();
 
     // Offer to reset a user's profile if it hasn't been used for 60 days.

browser/components/sessionstore/src/SessionStore.jsm

@@ -156,8 +156,8 @@ this.SessionStore = {
     SessionStoreInternal.canRestoreLastSession = val;
   },
 
-  init: function ss_init(aWindow) {
-    SessionStoreInternal.init(aWindow);
+  init: function ss_init() {
+    SessionStoreInternal.init();
   },
 
   getBrowserState: function ss_getBrowserState() {
@@ -368,15 +368,11 @@ let SessionStoreInternal = {
   /**
    * Initialize the sessionstore service.
    */
-  init: function (aWindow) {
+  init: function () {
     if (this._initialized) {
       throw new Error("SessionStore.init() must only be called once!");
     }
 
-    if (!aWindow) {
-      throw new Error("SessionStore.init() must be called with a valid window.");
-    }
-
     this._disabledForMultiProcess = Services.prefs.getBoolPref("browser.tabs.remote");
     if (this._disabledForMultiProcess) {
       this._deferredInitialized.resolve();
@@ -390,20 +386,6 @@ let SessionStoreInternal = {
 
     this._initPrefs();
     this._initialized = true;
-
-    // Wait until nsISessionStartup has finished reading the session data.
-    gSessionStartup.onceInitialized.then(() => {
-      // Parse session data and start restoring.
-      let initialState = this.initSession();
-
-      // Start tracking the given (initial) browser window.
-      if (!aWindow.closed) {
-        this.onLoad(aWindow, initialState);
-      }
-
-      // Let everyone know we're done.
-      this._deferredInitialized.resolve();
-    }, Cu.reportError);
   },
 
   initSession: function ssi_initSession() {
@@ -489,7 +471,6 @@ let SessionStoreInternal = {
       this._prefBranch.setBoolPref("sessionstore.resume_session_once", false);
 
     this._performUpgradeBackup();
-    this._sessionInitialized = true;
 
     return state;
   },
@@ -876,7 +857,34 @@ let SessionStoreInternal = {
   onOpen: function ssi_onOpen(aWindow) {
     let onload = () => {
       aWindow.removeEventListener("load", onload);
-      this.onLoad(aWindow);
+
+      if (this._sessionInitialized) {
+        this.onLoad(aWindow);
+        return;
+      }
+
+      // We can't call this.onLoad since initialization
+      // hasn't completed, so we'll wait until it is done.
+      // Even if additional windows are opened and wait
+      // for initialization as well, the first opened
+      // window should execute first, and this.onLoad
+      // will be called with the initialState.
+      gSessionStartup.onceInitialized.then(() => {
+        if (aWindow.closed) {
+          return;
+        }
+
+        if (this._sessionInitialized) {
+          this.onLoad(aWindow);
+        } else {
+          let initialState = this.initSession();
+          this._sessionInitialized = true;
+          this.onLoad(aWindow, initialState);
+
+          // Let everyone know we're done.
+          this._deferredInitialized.resolve();
+        }
+      }, Cu.reportError);
     };
 
     aWindow.addEventListener("load", onload);