Nest jQuery UI sortables

Answer 1

plugin fixes :

var sortable = $.widget("ui.sortable", $.ui.mouse, {
    _contactContainers: function(event) {   
            // never consider a container that's located within the item itself
            if($.contains(this.currentItem[0], this.containers[i].element[0]) || this.currentItem[0] === this.containers[i].element[0]) {
                continue;
            }
    }   
}