Made sure that animate callbacks get executed even when no properties are passed in. Fixes #5459.

src/fx.js

@@ -164,6 +164,10 @@ jQuery.fn.extend({
 				}
 			});
 
+			if ( jQuery.isEmptyObject( prop ) ) {
+				return optall.complete.call(this);
+			}
+
 			// For JS strict compliance
 			return true;
 		});
@@ -427,4 +431,4 @@ if ( jQuery.expr && jQuery.expr.filters ) {
 			return elem === fn.elem;
 		}).length;
 	};
-}
+}