Draggable: Cause focus and blur triggered every time when clicking the element

[flyoverL]

jsBin: ​http://jsbin.com/qahiyib/2/edit?html,js,console,output

At the version 1.12.1, Every time when clicking a draggable element, its focus event is always triggered.

Before the version 1.11.4, Every time when clicking a draggable element, both focus and blur event are always triggered.

I think the following source of draggable in JqueryUi may cause this problem:

_mouseUp: function( event ) {
                this._unblockFrames();

                //If the ddmanager is used for droppables, inform the manager that dragging has stopped (see #5003)
                if ( $.ui.ddmanager ) {
                        $.ui.ddmanager.dragStop(this, event);
                }

                var activeElement = $.ui.safeActiveElement( this.document[ 0 ] );
                // Only need to focus if the event occurred on the draggable itself, see #10527
                //if ( this.handleElement.is( event.target ) ) {
                if (this.handleElement.is( event.target)) {
                        // The interaction is over; whether or not the click resulted in a drag, focus the element
                        this.element.focus();
                }

                return $.ui.mouse.prototype._mouseUp.call(this, event);
        }