--- /dev/null	2018-01-29 13:46:29.000000000 +0800
+++ new/test/jdk/sun/nio/cs/MalformedSurrogateStringTest.java	2018-01-29 13:46:29.000000000 +0800
@@ -0,0 +1,88 @@
+/*
+ * 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 4153987 6354525
+ * @summary Malformed surrogates should be handled by the converter in
+ * substitution mode.
+ */
+
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+
+public class MalformedSurrogateStringTest {
+
+    public static void main(String[] args) throws Exception {
+
+        String fe = System.getProperty("file.encoding");
+        if (  fe.equalsIgnoreCase("UTF8")
+              || fe.equalsIgnoreCase("UTF-8")
+              || fe.equalsIgnoreCase("UTF_8"))
+            // This test is meaningless if the default charset
+            // does handle surrogates
+            return;
+
+        System.out.println("Testing string conversion...");
+        /* Example with malformed surrogate, and an offset */
+        String t = "abc\uD800\uDB00efgh";
+        String t2 = t.substring(2);
+        byte[] b = t2.getBytes();
+        System.err.println(b.length);
+        for (int i = 0; i < b.length; i++)
+            System.err.println("[" + i + "]" + "=" + (char) b[i]
+                               + "=" + (int) b[i]);
+        if (b.length != 7) {
+            throw new Exception("Bad string conversion for bad surrogate");
+        }
+
+        /* Example with a proper surrogate, no offset. Always worked */
+        String t3 = "abc\uD800\uDC00efgh";
+        byte[] b2 = t3.getBytes();
+        System.out.println(b2.length);
+        for(int i = 0; i < b2.length; i++)
+            System.err.println("[" + i + "]" + "=" + (char) b2[i]);
+        if (b2.length != 8) {
+            throw new Exception("Bad string conversion for good surrogate");
+        }
+
+        OutputStream os = new ByteArrayOutputStream();
+        OutputStreamWriter osw = new OutputStreamWriter(os);
+        System.out.println("Testing flush....");
+        /* Check for the case where the converter has a left over
+           high surrogate when flush is called on the converter */
+        osw.flush();
+        String s = "abc\uD800"; // High surrogate
+        char[] c = s.toCharArray();
+        osw.write(s, 0, 4);
+        osw.flush();
+
+        System.out.println("Testing convert...");
+        /* Verify that all other characters go through */
+        for (int k = 1; k < 65535 ; k++) {
+            osw.write("Char[" + k + "]=\"" + ((char) k) + "\"");
+        }
+
+    }
+}