Checking node object before checking its property.

chrome/browser/resources/bookmark_manager/js/main.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 (function() {
 /** @const */ var BookmarkList = bmm.BookmarkList;
 /** @const */ var BookmarkTree = bmm.BookmarkTree;
 /** @const */ var Command = cr.ui.Command;
@@ skipping 300 matching lines @@
  * Returns a promise for all the URLs in the {@code nodes} and the direct
  * children of {@code nodes}.
  * @param {!Array<BookmarkTreeNode>} nodes .
  * @return {!Promise<Array<string>>} .
  */
 function getAllUrls(nodes) {
   var urls = [];
 
   // Adds the node and all its direct children.
   function addNodes(node) {
-    if (node.id == 'new')
+    if (!node || node.id == 'new')
       return;
 
     if (node.children) {
       node.children.forEach(function(child) {
         if (!bmm.isFolder(child))
           urls.push(child.url);
       });
     } else {
       urls.push(node.url);
     }
   }
 
   // Get a future promise for the nodes.
+  // TODO(deepak.m1): All the nodes here should be existed. When we delete

[Bernhard Bauer, 2015/04/30 15:08:07]

Move this up to addNodes(), because that's where the check for undefined values
is (which shouldn't be necessary). Also, s/should be existed/should exist/.

[Deepak, 2015/04/30 16:11:19]

Done.

+  // the nodes then datamodel gets updated but still it shows deleted items as
+  // selected items and accessing those nodes throws chrome.runtime.lastError.
+  // Please refer https://crbug.com/480935.
   var promises = nodes.map(function(node) {
     if (bmm.isFolder(assert(node)))
       return bmm.loadSubtree(node.id);
     // Not a folder so we already have all the data we need.
     return Promise.resolve(node);
   });
 
   return Promise.all(promises).then(function(nodes) {
     nodes.forEach(addNodes);
     return urls;
@@ skipping 1172 matching lines @@
 
   cr.ui.FocusOutlineManager.forDocument(document);
   initializeSplitter();
   bmm.addBookmarkModelListeners();
   dnd.init(selectItemsAfterUserAction);
   bmm.tree.reload();
 }
 
 initializeBookmarkManager();
 })();