EE ROD on listbox override scrollToIndex

Steps to Reproduce

Run locally (somehow fiddle causes events to cascade and trigger an additional call)

https://zkfiddle.org/sample/3scu23s/2-listbox-ee-rod-scroll

Current Result

Listbox scroll to item 25

Expected Result

Listbox scroll to item 500

Debug Information

the scrollToIndex invokation is executed during the command processing, before init pads.

At this stage, the listbox hasn't triggered onRender, and pads are not initialized

So it scrolls by a ration of the currently rendered item count instead of the actual requested position

Workaround

wait for render if render is pending:

	<script><![CDATA[ 
	zk.afterLoad("zul.sel", function () {
	    var _xListbox = {};
	    zk.override(zul.sel.Listbox.prototype, _xListbox, {
	        scrollToIndex: function(index, scrollRatio) {
		    	function scrollLater(self,selfArgs){
		    		if(self._pendOnRender){
		    			setTimeout(function(){scrollLater(self, selfArgs)},0);
		    		}else{
		    			_xListbox.scrollToIndex.apply(self, selfArgs);
		    		}
		    	}
		    	scrollLater(this, arguments);
	        }
	     });
	});
]]></script>