Collapsible bug in Bootstrap based themes (Drupal).

scripts.js

// Place in theme file, eg. mytheme/js/script.js

(function($, Drupal, window, document, undefined) {

  Drupal.behaviors.bootstrap_based_theme = {
    attach : function(context, settings) {

      // Fix collapsible bug.
      $(".collapse").on("hidden.bs.collapse", function() {
        if ($(this).hasClass("in")) {
          $(this).removeClass("in");
        }
      });

    }
  };

})(jQuery, Drupal, this, this.document);