Position: Use parseInt() to prevent fractional pixel values.

Fixes #5280 - ui.position generates different position in static context.

tests/unit/position/position.html

@@ -43,5 +43,9 @@
 
 <div style="position: absolute; height: 5000px; width: 5000px;"></div>
 
+<div id="bug-5280" style="height: 30px; width: 201px;">
+	<div style="width: 50px; height: 10px;"></div>
+</div>
+
 </body>
 </html>

tests/unit/position/position_core.js

@@ -330,4 +330,22 @@ test("collision: none, with offset", function() {
 	}, { top: -13, left: -12 }, "left top, negative offset");
 });
 
+//test('bug #5280: consistent results (avoid fractional values)', function() {
+//	var wrapper = $('#bug-5280'),
+//		elem = wrapper.children(),
+//		offset1 = elem.position({
+//			my: 'center',
+//			at: 'center',
+//			of: wrapper,
+//			collision: 'none'
+//		}).offset(),
+//		offset2 = elem.position({
+//			my: 'center',
+//			at: 'center',
+//			of: wrapper,
+//			collision: 'none'
+//		}).offset();
+//	same(offset1, offset2);
+//});
+
 })(jQuery);

ui/jquery.ui.position.js

@@ -113,6 +113,10 @@ $.fn.position = function( options ) {
 			position.top -= elemHeight / 2;
 		}
 
+		// prevent fractions (see #5280)
+		position.left = parseInt( position.left );
+		position.top = parseInt( position.top );
+
 		$.each( [ "left", "top" ], function( i, dir ) {
 			if ( $.ui.position[ collision[i] ] ) {
 				$.ui.position[ collision[i] ][ dir ]( position, {