Fix the logic to set overflow:hidden on width & height animations - F…

…ixes #12117 - Closes gh-869

src/effects.js

@@ -269,7 +269,7 @@ function defaultPrefilter( elem, props, opts ) {
 	}
 
 	// height/width overflow pass
-	if ( elem.nodeType === 1 && ( props.height || props.width ) ) {
+	if ( elem.nodeType === 1 && ( "height" in props || "width" in props ) ) {
 		// Make sure that nothing sneaks out
 		// Record all 3 overflow attributes because IE does not
 		// change the overflow attribute when overflowX and

test/unit/effects.js

@@ -1785,4 +1785,18 @@ asyncTest("Animation callbacks (#11797)", 15, function() {
 	});
 });
 
+test( "Animate properly sets overflow hidden when animating width/height (#12117)", 4, function() {
+	jQuery.each( [ "height", "width" ], function( _, prop ) {
+		jQuery.each( [ 100, 0 ], function( _, value ) {
+			var div = jQuery("<div>"),
+				props = {};
+			props[ prop ] = value;
+			div.animate( props, 1 );
+			equal( div.css( "overflow" ), "hidden",
+				"overflow: hidden set when animating " + prop + " to " + value );
+			div.stop();
+		});
+	});
+});
+
 } // if ( jQuery.fx )