--- /dev/null	2018-08-06 19:33:22.830000512 +0900
+++ new/test/jdk/sun/nio/cs/TestGB18030.java	2018-10-02 18:05:44.845265277 +0900
@@ -0,0 +1,82 @@
+/*
+ * 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 8211382
+ * @summary Check GB18030
+ * @modules jdk.charsets
+ */
+
+import java.io.*;
+import java.nio.*;
+import java.nio.charset.*;
+
+public class TestGB18030 {
+    public static void gb18030_1(boolean useDirect) throws Exception {
+        for(char ch : new char[]{'\uFFFE', '\uFFFF'}) {
+            char[] ca = new char[]{ch};
+            Charset cs = Charset.forName("GB18030");
+            CharsetEncoder ce = cs.newEncoder();
+            CharsetDecoder cd = cs.newDecoder();
+            CharBuffer cb = CharBuffer.wrap(ca);
+            ByteBuffer bb;
+            if (useDirect) {
+                bb = ByteBuffer.allocateDirect(
+                    (int)Math.ceil(ce.maxBytesPerChar()));
+            } else {
+                bb = ByteBuffer.allocate(
+                    (int)Math.ceil(ce.maxBytesPerChar()));
+            }
+            CoderResult cr = ce.encode(cb, bb, true);
+            if (!cr.isUnderflow()) {
+                throw new RuntimeException(
+                    String.format("Encoder Error: \\u%04X: direct=%b: %s",
+                        (int)ch,
+                        useDirect,
+                        cr.toString()));
+            }
+            bb.position(0);
+            cb = CharBuffer.allocate((int)Math.ceil(
+                cd.maxCharsPerByte()*bb.limit()));
+            cr = cd.decode(bb, cb, true);
+            if (!cr.isUnderflow()) {
+                throw new RuntimeException(
+                    String.format("Decoder Error: \\u%04X: direct=%b: %s",
+                        (int)ch,
+                        useDirect,
+                        cr.toString()));
+            }
+            if (ca[0] != cb.get(0)) {
+                throw new RuntimeException(
+                    String.format("direct=%b: \\u%04X <> \\u%04X",
+                        useDirect,
+                        (int)ca[0],
+                        (int)cb.get(0)));
+            }
+        }
+    }
+    public static void main(String args[]) throws Exception {
+        gb18030_1(false);
+        gb18030_1(true);
+    }
+}