Fix for animating hyphenated CSS properties. Fixes #4156.

src/fx.js

@@ -109,6 +109,14 @@ jQuery.fn.extend({
 				self = this;
 
 			for ( p in prop ) {
+				var name = p.replace(rdashAlpha, fcamelCase);
+
+				if ( p !== name ) {
+					prop[ name ] = prop[ p ];
+					delete prop[ p ];
+					p = name;
+				}
+
 				if ( prop[p] == "hide" && hidden || prop[p] == "show" && !hidden )
 					return opt.complete.call(this);
 

test/unit/fx.js

@@ -100,6 +100,18 @@ test("animate duration 0", function() {
 	});	
 });
 
+test("animate hyphenated properties", function(){
+	expect(1);
+	stop();
+
+	jQuery("#nothiddendiv")
+		.css("font-size", 10)
+		.animate({"font-size": 20}, 200, function(){
+			equals( this.style.fontSize, "20px", "The font-size property was animated." );
+			start();
+		});
+});
+
 test("animate non-element", function(){
 	expect(1);
 	stop();