Bug 1363078 - Refuse to insert lazy browsers in closed windows. r=dao

MozReview-Commit-ID: Gc783ESwXjv

browser/base/content/tabbrowser.xml

@@ -2149,8 +2149,8 @@
           <![CDATA[
             "use strict";
 
-            // If browser is already inserted don't do anything.
-            if (aTab.linkedPanel) {
+            // If browser is already inserted or window is closed don't do anything.
+            if (aTab.linkedPanel || window.closed) {
               return;
             }
 

browser/components/sessionstore/test/browser.ini

@@ -225,6 +225,7 @@ skip-if = true
 [browser_625016.js]
 skip-if = os == "mac"
 
+[browser_906076_lazy_tabs.js]
 [browser_911547.js]
 [browser_send_async_message_oom.js]
 [browser_multiple_navigateAndRestore.js]

browser/components/sessionstore/test/browser_906076_lazy_tabs.js

@@ -0,0 +1,88 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const TEST_STATE = {
+  windows: [{
+    tabs: [
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+      { entries: [{ url: "http://example.com" }] },
+    ]
+  }]
+};
+
+function countNonLazyTabs(win) {
+  win = win || window;
+  let count = 0;
+  for (let browser of win.gBrowser.browsers) {
+    if (browser.isConnected) {
+      count++;
+    }
+  }
+  return count;
+}
+
+/**
+ * Test that lazy browsers do not get prematurely inserted by
+ * code accessing browser bound properties on the unbound browser.
+ */
+
+add_task(function* test() {
+  yield SpecialPowers.pushPrefEnv({
+    "set": [
+      ["browser.sessionstore.restore_on_demand", true],
+      ["browser.sessionstore.restore_tabs_lazily", true],
+    ]
+  });
+
+  let backupState = SessionStore.getBrowserState();
+
+  yield promiseBrowserState(TEST_STATE);
+
+  info("Check that no lazy browsers get unnecessarily inserted after session restore");
+  is(countNonLazyTabs(), 1, "Window has only 1 non-lazy tab");
+
+  yield TestUtils.topicObserved("sessionstore-state-write-complete");
+
+  // When sessionstore write occurs, tabs are checked for state changes.
+  // Make sure none of them insert their browsers when this happens.
+  info("Check that no lazy browsers get inserted after sessionstore write");
+  is(countNonLazyTabs(), 1, "Window has only 1 non-lazy tab");
+
+  info("Check that lazy browser gets inserted properly");
+  ok(!gBrowser.browsers[1].isConnected, "The browser that we're attempting to insert is indeed lazy");
+  gBrowser._insertBrowser(gBrowser.tabs[1]);
+  is(countNonLazyTabs(), 2, "Window now has 2 non-lazy tabs");
+
+  // Check if any lazy tabs got inserted when window closes.
+  let newWindow = yield promiseNewWindowLoaded();
+
+  SessionStore.setWindowState(newWindow, JSON.stringify(TEST_STATE));
+
+  yield new Promise(resolve => {
+    newWindow.addEventListener("unload", () => {
+      info("Check that no lazy browsers get inserted when window closes");
+      is(countNonLazyTabs(newWindow), 1, "Window has only 1 non-lazy tab");
+
+      info("Check that it is not possible to insert a lazy browser after the window closed");
+      ok(!newWindow.gBrowser.browsers[1].isConnected, "The browser that we're attempting to insert is indeed lazy");
+      newWindow.gBrowser._insertBrowser(newWindow.gBrowser.tabs[1]);
+      is(countNonLazyTabs(newWindow), 1, "Window still has only 1 non-lazy tab");
+
+      resolve();
+    }, { once: true });
+
+    newWindow.close();
+  });
+
+  // Cleanup.
+  yield promiseBrowserState(backupState);
+});
+