--- old/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/JSType.java	2014-11-26 14:36:26.000000000 +0400
+++ new/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/JSType.java	2014-11-26 14:36:26.000000000 +0400
@@ -714,6 +714,9 @@
      * @return a number
      */
     public static double toNumber(final Object obj) {
+        if (obj instanceof Double) {
+            return (Double)obj;
+        }
         if (obj instanceof Number) {
             return ((Number)obj).doubleValue();
         }