Strange Quicktabs behavior with Chrome [#1586158]

I have a block with the following Quicktabs code:

$view_result = views_get_view_result('award_recipients', $display_id = "default");
        foreach($view_result as $item){
            $node = node_load($item->nid);
            $tabs[$node->nid] = array(
              'title' => $node->field_year[0]['value'],
              'type' => 'freetext',
              'text' => '<h1 class="title">' . t($node->title). '</h1>' . t($node->body),
           );
        }
        $quicktabs['qtid'] = 'award-recipients';
        $quicktabs['tabs'] = $tabs;
        $quicktabs['style'] = 'Navlist';
        $quicktabs['ajax'] = FALSE;
        
        print theme('quicktabs', $quicktabs);

My block works fine in all browsers except Chrome where the order is reversed. See screenshots of the source code from Chrome and Safari.
Note that in Chrome the active tab "qtab-81" activates the tabpage__49, NOT tabpage__81 like correctly displayed in all other browsers.

Comment	File	Size	Author
	Chrome-browser-Incorrect-display.png	98.71 KB	nelslynn
	All-Browsers-correct-display.png	99.02 KB	nelslynn

Comments

Comment #1

adamdicarlo commented 27 August 2013 at 00:27

I just tracked this down after seeing the same issue.

The problem is in how Quicktabs's JavaScript works; unfortunately, I believe the code has a major flaw. Snippet:

Drupal.quicktabs.tab = function (el) {
  // ...
  var i = 0;
  for (var key in Drupal.settings.quicktabs[qtKey].tabs) {
    if (i == this.tabIndex) {
      this.tabObj = Drupal.settings.quicktabs[qtKey].tabs[key];
      this.tabKey = key;
    }
    i++;
  }
  // ...

This code is relying on iteration of object properties to be in the same order as those properties were added to the object. Unfortunately, while apparently most/all browsers happen to provide that characteristic, it is specifically not guaranteed:

ECMAScript® Language Specification for for-in loops

My guess: V8 recently implemented an optimization or slight change that causes code that makes this incorrect ordering assumption to break.