From e220cf2a7dc709fdbbdfeacbb29378e005a0afd8 Mon Sep 17 00:00:00 2001
From: Corey Frang <gnarf@gnarf.net>
Date: Tue, 27 Mar 2012 14:06:49 -0500
Subject: [PATCH] Effects: Backporting e8ba367 to 1-8-stable - Fixes #8113 -
 addClass not animating

---
 ui/jquery.effects.core.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ui/jquery.effects.core.js b/ui/jquery.effects.core.js
index 74b29af26..27bbe7c31 100644
--- a/ui/jquery.effects.core.js
+++ b/ui/jquery.effects.core.js
@@ -236,7 +236,7 @@ $.effects.animateClass = function(value, duration, easing, callback) {
 			originalStyleAttr = that.attr('style') || ' ',
 			originalStyle = filterStyles(getElementStyles.call(this)),
 			newStyle,
-			className = that.attr('class');
+			className = that.attr('class') || "";
 
 		$.each(classAnimationActions, function(i, action) {
 			if (value[action]) {