--- a/nashorn/src/jdk/nashorn/internal/objects/NativeDate.java	Wed Apr 24 13:28:25 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/objects/NativeDate.java	Wed Apr 24 13:34:22 2013 +0200
@@ -182,7 +182,8 @@
 
     @Override
     public String safeToString() {
-        return "[Date " + toISOStringImpl(this) + "]";
+        final String str = isValidDate() ? toISOStringImpl(this) : INVALID_DATE;
+        return "[Date " + str + "]";
     }
 
     @Override

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8012931.js	Wed Apr 24 13:34:22 2013 +0200
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * JDK-8012931: NativeDate.safeToString() throws RangeError for invalid date
+ *
+ * @test
+ * @run
+ */
+
+var d = new Date(NaN);
+d.toString = Number.prototype.toString;
+
+try {
+    d.toString();
+} catch(e) {
+    print(e);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8012931.js.EXPECTED	Wed Apr 24 13:34:22 2013 +0200
@@ -0,0 +1,1 @@
+TypeError: [Date Invalid Date] is not a Number