Plugings that provide extended_valid_elements are ignored due to error in panopoly_wysiwyg_alter_wysiwyg_editor_settings()

I have defined my own simple plugin using hook_wysiwyg_plugin() hook. Basically all it has to do is to provide the list of extended_valid_elements so that editor wouldn't cut them off from textaerea.

However, I noticed that elements which I've put into extended_valid_elements are not present in settings of wysisyg editor on the page - Drupal.settings.wysisyg.configs.tinymce.formatpanopoly_wysiwyg_text.extended_valid_elements

So I started my debugger. And here is what I've found:
panopoly_wysiwyg_alter_wysiwyg_editor_settings() (which is called from panopoly_wysiwyg_wysiwyg_editor_settings_alter()) plays with some params inside $settings array (among which is also extended_valid_elements). The block of code that screw everything is the following one:

        // When adding new elements to $settings['extended_valid_elements'], make sure
        // that we're merging, and not overwriting.
        $settings_array = array();
        foreach($settings['extended_valid_elements'] as $tag) {
          if (strpos("[", $tag) !== FALSE) {
            list($tag, $allowed_attributes) = explode('[', $tag);
            ...
          }
        }

some one had messed up order of params that are passed to strpos() func inside if() clause - haystack should be passed firts, needle - second, but not vise versa. Because of that code inside if() has no chances to be executed.

And here is the patch.