--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/nio/MappedByteBuffer/SubclassCastUOE.java	Mon Feb 12 08:19:23 2018 -0800
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2018, 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.
+ */
+
+/* @test
+ * @bug 8191416
+ * @summary Verify no UnsupportedOperationException for cast subclass
+ */
+
+import java.nio.ByteBuffer;
+import java.nio.MappedByteBuffer;
+
+public class SubclassCastUOE {
+    public static void main(String[] args) throws Exception {
+        ByteBuffer buf = ByteBuffer.allocateDirect(37);
+
+        if (!(buf instanceof MappedByteBuffer)) {
+            throw new RuntimeException("Direct buffer not a MappedByteBuffer");
+        }
+
+        if (((MappedByteBuffer)buf).load() != buf) {
+            throw new RuntimeException("load() did not return same buffer");
+        }
+
+        if (!((MappedByteBuffer)buf).isLoaded()) {
+            throw new RuntimeException("isLoaded() returned false");
+        }
+
+        if (((MappedByteBuffer)buf).force() != buf) {
+            throw new RuntimeException("force() did not return same buffer");
+        }
+    }
+}