:data selector fails to return results when the data is set to empty string

The :data additional selector in jquery.ui.core.js does not match elements that contain empty strings as data.

HTML:

    <ol id="test">
      <li id="hasdata">hello</li>
      <li>foobar</li>
    </ol>

CODE:

$("#hasdata").data("empty", "");
$("#hasdata").data("hello", "oh hai");

console.debug('has data:', $("#hasdata").data() );
        
var cant_find = $("#test").find("li:data(empty)");
console.debug("selector fails to see the empty string in the data", cant_find);
        
var can_find = $("#test").find("li:data(hello)");
console.debug("selector is cool with a non empty string", can_find);

This is likely due to this in ui.core.js, line 181:

	data: function(elem, i, match) {
		return !!$.data(elem, match[3]);
	}

Because "empty string" evaluates to false, !!"" returns false, even though the key exists in the data. Should probably be something like

 !($.data(elem, match[3]) === undefined)