diff -r 000000000000 -r 1918ee327afb src/3rdparty/webkit/JavaScriptCore/runtime/ErrorPrototype.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/3rdparty/webkit/JavaScriptCore/runtime/ErrorPrototype.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,68 @@
+/*
+ *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
+ *  Copyright (C) 2003, 2008 Apple Inc. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include "config.h"
+#include "ErrorPrototype.h"
+
+#include "JSFunction.h"
+#include "JSString.h"
+#include "ObjectPrototype.h"
+#include "PrototypeFunction.h"
+#include "UString.h"
+
+namespace JSC {
+
+ASSERT_CLASS_FITS_IN_CELL(ErrorPrototype);
+
+static JSValue JSC_HOST_CALL errorProtoFuncToString(ExecState*, JSObject*, JSValue, const ArgList&);
+
+// ECMA 15.9.4
+ErrorPrototype::ErrorPrototype(ExecState* exec, NonNullPassRefPtr<Structure> structure, Structure* prototypeFunctionStructure)
+    : ErrorInstance(structure)
+{
+    // The constructor will be added later in ErrorConstructor's constructor
+
+    putDirectWithoutTransition(exec->propertyNames().name, jsNontrivialString(exec, "Error"), DontEnum);
+    putDirectWithoutTransition(exec->propertyNames().message, jsNontrivialString(exec, "Unknown error"), DontEnum);
+
+    putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 0, exec->propertyNames().toString, errorProtoFuncToString), DontEnum);
+}
+
+JSValue JSC_HOST_CALL errorProtoFuncToString(ExecState* exec, JSObject*, JSValue thisValue, const ArgList&)
+{
+    JSObject* thisObj = thisValue.toThisObject(exec);
+
+    UString s = "Error";
+
+    JSValue v = thisObj->get(exec, exec->propertyNames().name);
+    if (!v.isUndefined())
+        s = v.toString(exec);
+
+    v = thisObj->get(exec, exec->propertyNames().message);
+    if (!v.isUndefined()) {
+        // Mozilla-compatible format.
+        s += ": ";
+        s += v.toString(exec);
+    }
+
+    return jsNontrivialString(exec, s);
+}
+
+} // namespace JSC