--- old/src/java.desktop/share/classes/javax/swing/RepaintManager.java	2014-08-26 11:17:39.000000000 +0800
+++ new/src/java.desktop/share/classes/javax/swing/RepaintManager.java	2014-08-26 11:17:38.000000000 +0800
@@ -990,10 +990,7 @@
      * @return a String representation of this object
      */
     public synchronized String toString() {
-        StringBuilder sb = new StringBuilder();
-        if(dirtyComponents != null)
-            sb.append("" + dirtyComponents);
-        return sb.toString();
+        return dirtyComponents != null ? dirtyComponents.toString() : "";
     }