Bug 682681 tab.title should never be empty

packages/addon-kit/docs/tabs.md

@@ -171,7 +171,7 @@ passed the `Tab` object that triggered the event.
 
 <api name="title">
 @property {string}
-The title of the page currently loaded in the tab.
+The title of the tab (usually the title of the page currently loaded in the tab)
 This property can be set to change the tab title.
 </api>
 

packages/addon-kit/tests/test-tabs.js

@@ -29,6 +29,54 @@ exports.testActiveTab_getter = function(test) {
   });
 };
 
+// Bug 682681 - tab.title should never be empty
+exports.testBug682681_aboutURI = function(test) {
+  test.waitUntilDone();
+
+  openBrowserWindow(function(window, browser) {
+    let tabs = require("tabs");
+
+    tabs.on('ready', function onReady(tab) {
+      tabs.removeListener('ready', onReady);
+
+      test.assertEqual(tab.title, "New Tab", "title of about: tab is not blank");
+
+      // end of test
+      closeBrowserWindow(window, function() test.done());
+    });
+
+    // open a about: url
+    tabs.open({
+      url: "about:blank",
+      inBackground: true
+    });
+  });
+};
+
+// related to Bug 682681
+exports.testTitleForDataURI = function(test) {
+  test.waitUntilDone();
+
+  openBrowserWindow(function(window, browser) {
+    let tabs = require("tabs");
+
+    tabs.on('ready', function onReady(tab) {
+      tabs.removeListener('ready', onReady);
+
+      test.assertEqual(tab.title, "tab", "data: title is not Connecting...");
+
+      // end of test
+      closeBrowserWindow(window, function() test.done());
+    });
+
+    // open a about: url
+    tabs.open({
+      url: "data:text/html;charset=utf-8,<title>tab</title>",
+      inBackground: true
+    });
+  });
+};
+
 // test 'BrowserWindow' instance creation on tab 'activate' event
 // See bug 648244: there was a infinite loop.
 exports.testBrowserWindowCreationOnActivate = function(test) {

packages/api-utils/lib/tabs/tab.js

@@ -11,7 +11,11 @@ const { defer } = require("../functional");
 const { EVENTS } = require("./events");
 const { getThumbnailURIForWindow } = require("../utils/thumbnail");
 const { getFaviconURIForLocation } = require("../utils/data");
-
+const {
+  getOwnerWindow,
+  getBrowserForTab,
+  getTabTitle
+} = require("./utils");
 
 
 // Array of the inner instances of all the wrapped tabs.
@@ -82,11 +86,11 @@ const TabTrait = Trait.compose(EventEmitter, {
   /**
    * Browser DOM element where page of this tab is currently loaded.
    */
-  get _browser() this._window.gBrowser.getBrowserForTab(this._tab),
+  get _browser() getBrowserForTab(this._tab),
   /**
    * Window DOM element containing this tab.
    */
-  get _window() this._tab.ownerDocument.defaultView,
+  get _window() getOwnerWindow(this._tab),
   /**
    * Document object of the page that is currently loaded in this tab.
    */
@@ -101,8 +105,8 @@ const TabTrait = Trait.compose(EventEmitter, {
    * Changing this property changes an actual title.
    * @type {String}
    */
-  get title() this._contentDocument.title,
-  set title(value) this._contentDocument.title = String(value),
+  get title() getTabTitle(this._tab),
+  set title(value) this._tab.label = String(value),
   /**
    * Location of the page currently loaded in this tab.
    * Changing this property will loads page under under the specified location.

packages/api-utils/lib/tabs/utils.js

@@ -49,16 +49,31 @@ function isTabOpen(tab) {
 exports.isTabOpen = isTabOpen;
 
 function closeTab(tab) {
-  return getOwnerWindow(tab).gBrowser.removeTab(tab);
+  return getGBrowserForTab(tab).removeTab(tab);
 }
 exports.closeTab = closeTab;
 
 function activateTab(tab) {
-  getOwnerWindow(tab).gBrowser.selectedTab = tab;
+  getGBrowserForTab(tab).selectedTab = tab;
 }
 exports.activateTab = activateTab;
 
 function getURI(tab) {
   return tab.linkedBrowser.currentURI.spec;
 }
 exports.getURI = getURI;
+
+function getGBrowserForTab(tab) {
+  return getOwnerWindow(tab).gBrowser;
+}
+exports.getGBrowserForTab = getGBrowserForTab;
+
+function getBrowserForTab(tab) {
+  return getGBrowserForTab(tab).getBrowserForTab(tab);
+}
+exports.getBrowserForTab = getBrowserForTab;
+
+function getTabTitle(tab) {
+  return getBrowserForTab(tab).contentDocument.title || tab.label;
+}
+exports.getTabTitle = getTabTitle;