--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/io/Serializable/classDescHooks/ExternLoopback.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2001 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+ * @bug 4461737
+ * @summary Verify that serialization functions properly for externalizable
+ *          classes if ObjectInputStream.readClassDescriptor() returns a local
+ *          class descriptor.
+ */
+
+import java.io.*;
+import java.util.*;
+
+class LoopbackOutputStream extends ObjectOutputStream {
+    LinkedList descs;
+
+    LoopbackOutputStream(OutputStream out, LinkedList descs)
+        throws IOException
+    {
+        super(out);
+        this.descs = descs;
+    }
+
+    protected void writeClassDescriptor(ObjectStreamClass desc)
+        throws IOException
+    {
+        descs.add(desc);
+    }
+}
+
+class LoopbackInputStream extends ObjectInputStream {
+    LinkedList descs;
+
+    LoopbackInputStream(InputStream in, LinkedList descs) throws IOException {
+        super(in);
+        this.descs = descs;
+    }
+
+    protected ObjectStreamClass readClassDescriptor()
+        throws IOException, ClassNotFoundException
+    {
+        return (ObjectStreamClass) descs.removeFirst();
+    }
+}
+
+public class ExternLoopback implements Externalizable {
+
+    String a, b, c;
+
+    public ExternLoopback() {
+    }
+
+    ExternLoopback(String a, String b, String c) {
+        this.a = a;
+        this.b = b;
+        this.c = c;
+    }
+
+    public void writeExternal(ObjectOutput out) throws IOException {
+        out.writeBoolean(false);
+        out.writeObject(a);
+        out.writeObject(b);
+        out.writeObject(c);
+    }
+
+    public void readExternal(ObjectInput in)
+        throws IOException, ClassNotFoundException
+    {
+        in.readBoolean();
+        a = (String) in.readObject();
+        b = (String) in.readObject();
+        c = (String) in.readObject();
+    }
+
+    public boolean equals(Object obj) {
+        if (!(obj instanceof ExternLoopback)) {
+            return false;
+        }
+        ExternLoopback other = (ExternLoopback) obj;
+        return streq(a, other.a) && streq(b, other.b) && streq(c, other.c);
+    }
+
+    static boolean streq(String s1, String s2) {
+        return (s1 != null) ? s1.equals(s2) : (s2 == null);
+    }
+
+    public static void main(String[] args) throws Exception {
+        ExternLoopback lb = new ExternLoopback("foo", "bar", "baz");
+        LinkedList descs = new LinkedList();
+        ByteArrayOutputStream bout = new ByteArrayOutputStream();
+        LoopbackOutputStream lout = new LoopbackOutputStream(bout, descs);
+        lout.writeObject(lb);
+        lout.close();
+
+        LoopbackInputStream lin = new LoopbackInputStream(
+            new ByteArrayInputStream(bout.toByteArray()), descs);
+        ExternLoopback lbcopy = (ExternLoopback) lin.readObject();
+        if (!lb.equals(lbcopy)) {
+            throw new Error();
+        }
+    }
+}