diff --git a/mozilla/js/rhino/src/org/mozilla/javascript/ScriptRuntime.java b/mozilla/js/rhino/src/org/mozilla/javascript/ScriptRuntime.java
index 0787e783bb4..60d539db249 100644
--- a/mozilla/js/rhino/src/org/mozilla/javascript/ScriptRuntime.java
+++ b/mozilla/js/rhino/src/org/mozilla/javascript/ScriptRuntime.java
@@ -516,7 +516,7 @@ public class ScriptRuntime {
             if (!Character.isJavaIdentifierPart(s.charAt(i)))
                 return false;
         }
-        return true;
+        return !TokenStream.isKeyword(s);
     }
 
     /**
diff --git a/mozilla/js/rhino/src/org/mozilla/javascript/TokenStream.java b/mozilla/js/rhino/src/org/mozilla/javascript/TokenStream.java
index 11da1efc260..a56d3efd3d5 100644
--- a/mozilla/js/rhino/src/org/mozilla/javascript/TokenStream.java
+++ b/mozilla/js/rhino/src/org/mozilla/javascript/TokenStream.java
@@ -123,7 +123,12 @@ public class TokenStream
         return "";
     }
 
-    private int stringToKeyword(String name) {
+    static boolean isKeyword(String s)
+    {
+        return Token.EOF != stringToKeyword(s);
+    }
+
+    private static int stringToKeyword(String name) {
 // #string_id_map#
 // The following assumes that Token.EOF == 0
         final int