Added tests for #3981 - Slider label ID gets overwritten

tests/unit/slider/index.html

@@ -91,6 +91,11 @@ <h2 id="qunit-userAgent"></h2>
 		<label for="empty-string-val-slider">Input slider:</label>
 		<input type="range" name="empty-string-val-slider" id="empty-string-val-slider" value="25" min="10" max="100" step="20"/>
 	</div>
+
+	<div data-role="fieldcontain">
+		<label id="label-id" for="label-id-slider">Input slider:</label>
+		<input type="range" name="slider" id="label-id-slider" value="25" min="0" max="100"/>
+	</div>
 </div>
 
 <div id="enhancetest">

tests/unit/slider/slider_core.js

@@ -44,4 +44,15 @@
 		same( $unhighlighted.siblings( ".ui-slider" ).find( ".ui-slider-bg" ).length, 0,
 					"unhighlighted slider _not_ should have a div for the track bg" );
 	});
-})( jQuery );
+
+	test( "labels that have id keep that id", function() {
+		var label = $( "[for=label-id-slider]" );
+		equal(label.attr( "id" ), "label-id", "label id was not changed" );
+	});
+
+	test( "labels without an id get an id", function() {
+		var slider = $( "#empty-string-val-slider" ),
+			label = $( "[for=empty-string-val-slider]" );
+		equal(label.attr( "id" ), slider.attr( "id" ) + "-label", "the label id is based off the slider id" );
+	});
+})( jQuery );