Fix bug 541530. r=jst sr=brendan

dom/base/nsDOMClassInfo.cpp

@@ -584,7 +584,8 @@ static nsDOMClassInfoData sClassInfoData[] = {
                            WINDOW_SCRIPTABLE_FLAGS)
 
   NS_DEFINE_CLASSINFO_DATA(Location, nsLocationSH,
-                           DOM_DEFAULT_SCRIPTABLE_FLAGS)
+                           (DOM_DEFAULT_SCRIPTABLE_FLAGS &
+                            ~nsIXPCScriptable::ALLOW_PROP_MODS_TO_PROTOTYPE))
 
   NS_DEFINE_CLASSINFO_DATA(Navigator, nsNavigatorSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS |
@@ -6538,7 +6539,10 @@ nsWindowSH::NewResolve(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
 
     JSBool ok = ::JS_DefineUCProperty(cx, obj, ::JS_GetStringChars(str),
                                       ::JS_GetStringLength(str), v, nsnull,
-                                      nsnull, JSPROP_ENUMERATE);
+                                      nsnull,
+                                      JSPROP_PERMANENT |
+                                      JSPROP_READONLY |
+                                      JSPROP_ENUMERATE);
 
     if (!ok) {
       return NS_ERROR_FAILURE;
@@ -8155,7 +8159,10 @@ nsDocumentSH::NewResolve(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
     JSString *str = JSVAL_TO_STRING(id);
     JSBool ok = ::JS_DefineUCProperty(cx, obj, ::JS_GetStringChars(str),
                                       ::JS_GetStringLength(str), v, nsnull,
-                                      nsnull, JSPROP_ENUMERATE);
+                                      nsnull,
+                                      JSPROP_PERMANENT |
+                                      JSPROP_READONLY |
+                                      JSPROP_ENUMERATE);
 
     if (!ok) {
       return NS_ERROR_FAILURE;