--- a/nashorn/src/jdk/nashorn/internal/objects/NativeFunction.java	Mon Apr 15 20:12:50 2013 +0530
+++ b/nashorn/src/jdk/nashorn/internal/objects/NativeFunction.java	Wed Apr 17 16:52:06 2013 +0530
@@ -81,23 +81,13 @@
 
         Object[] args = null;
 
-        if (ScriptObject.isArray(array)) {
-            args = ((NativeArray)array).asObjectArray();
-        } else if (array instanceof ScriptObject) {
+        if (array instanceof ScriptObject) {
             // look for array-like object
             final ScriptObject sobj = (ScriptObject)array;
             final Object       len  = sobj.getLength();
-
-            if (len == UNDEFINED || len == null) {
-                throw typeError("function.apply.expects.array");
-            }
+            final int n = (int)JSType.toUint32(len);
 
-            final int n = (int)JSType.toUint32(len);
-            if (n != JSType.toNumber(len)) {
-                throw typeError("function.apply.expects.array");
-            }
-
-            args = new Object[(int)JSType.toUint32(len)];
+            args = new Object[n];
             for (int i = 0; i < args.length; i++) {
                 args[i] = sobj.get(i);
             }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8012457.js	Wed Apr 17 16:52:06 2013 +0530
@@ -0,0 +1,46 @@
+/*
+ * 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-8012457: Function.prototype.apply should accept any array-like argument for function arguments
+ *
+ * @test
+ * @run
+ */
+
+// no exception for these
+Function().apply(null, {length: null})
+Function().apply(null, {length: 0.1})
+
+// getter should be called
+var getter_0_called = false;
+
+Function().apply(null, 
+    Object.defineProperty([],"0",
+        {  get: function(){ getter_0_called = true; return 0 }
+    })
+);
+
+if (! getter_0_called) {
+    fail("getter for '0' of arguments array not called");
+}