--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/FieldObjectCreator.java	Mon Sep 15 15:18:13 2014 +0530
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/FieldObjectCreator.java	Mon Sep 15 17:51:11 2014 +0200
@@ -231,7 +231,7 @@
             if (symbol != null) {
                 if (hasArguments() && symbol.isParam()) {
                     symbol.setFieldIndex(paramCount++);
-                } else {
+                } else if (!isValidArrayIndex(getArrayIndex(tuple.key))) {
                     symbol.setFieldIndex(fieldCount++);
                 }
             }

--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/PropertyMap.java	Mon Sep 15 15:18:13 2014 +0530
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/PropertyMap.java	Mon Sep 15 17:51:11 2014 +0200
@@ -568,9 +568,7 @@
         for (final Property property : otherProperties) {
             // This method is only safe to use with non-slotted, native getter/setter properties
             assert property.getSlot() == -1;
-            if (isValidArrayIndex(getArrayIndex(property.getKey()))) {
-                newMap.setContainsArrayKeys();
-            }
+            assert !(isValidArrayIndex(getArrayIndex(property.getKey())));
         }
 
         return newMap;

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8056978.js	Mon Sep 15 17:51:11 2014 +0200
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2014, 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-8056978: ClassCastException: cannot cast jdk.nashorn.internal.scripts.JO*
+ *
+ * @test
+ * @run
+ */
+
+var obj1 = {
+    'name': 'test name',
+    '1': '1',
+    '2': '2',
+    '3': '3',
+    '4': '4',
+    '5': '5'
+};
+
+var obj2 = {
+    'name': 'hello'
+};
+
+print(obj2['name']);
+print(obj2.name);
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8056978.js.EXPECTED	Mon Sep 15 17:51:11 2014 +0200
@@ -0,0 +1,2 @@
+hello
+hello