--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/JSObjectLinker.java	Thu Mar 09 21:35:20 2017 +0000
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/JSObjectLinker.java	Fri Mar 10 18:30:39 2017 +0100
@@ -176,6 +176,8 @@
             final int index = getIndex((Number)key);
             if (index > -1) {
                 return ((JSObject)jsobj).getSlot(index);
+            } else {
+                return ((JSObject)jsobj).getMember(JSType.toString(key));
             }
         } else if (isString(key)) {
             final String name = key.toString();
@@ -193,7 +195,12 @@
         if (key instanceof Integer) {
             ((JSObject)jsobj).setSlot((Integer)key, value);
         } else if (key instanceof Number) {
-            ((JSObject)jsobj).setSlot(getIndex((Number)key), value);
+            final int index = getIndex((Number)key);
+            if (index > -1) {
+                ((JSObject)jsobj).setSlot(index, value);
+            } else {
+                ((JSObject)jsobj).setMember(JSType.toString(key), value);
+            }
         } else if (isString(key)) {
             ((JSObject)jsobj).setMember(key.toString(), value);
         }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8176511.js	Fri Mar 10 18:30:39 2017 +0100
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2017, 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-8176511: JSObject property access is broken for numeric keys outside the int range
+ *
+ * @test
+ * @run
+ */
+
+
+var reassignWithNewGlobal = loadWithNewGlobal({
+    script: '(function (o, i) { o[i] = o[i]; })', name: 'internal.js'
+
+});
+
+function test(i) {
+    var o = {};
+    o[i] = true;
+    var before = JSON.stringify(o);
+    reassignWithNewGlobal(o, i);
+    var after = JSON.stringify(o);
+    Assert.assertEquals(before, after);
+}
+
+test(-2147483649);
+test(-2147483648);
+test(2147483647);
+test(2147483648);
+