--- a/src/share/classes/sun/security/util/DerOutputStream.java	Mon Jun 29 16:28:58 2009 -0700
+++ b/src/share/classes/sun/security/util/DerOutputStream.java	Tue Jun 30 11:55:58 2009 +0800
@@ -1,5 +1,5 @@
 /*
- * Copyright 1996-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1996-2009 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
@@ -200,12 +200,12 @@
         // Reduce them to the least number of bytes needed to
         // represent this int
 
-        if (bytes[0] == 0xff) {
+        if (bytes[0] == (byte)0xff) {
 
             // Eliminate redundant 0xff
 
             for (int j = 0; j < 3; j++) {
-                if ((bytes[j] == 0xff) &&
+                if ((bytes[j] == (byte)0xff) &&
                     ((bytes[j+1] & 0x80) == 0x80))
                     start++;
                 else

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/sun/security/util/DerValue/NegInt.java	Tue Jun 30 11:55:58 2009 +0800
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2009 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 6855671
+ * @summary DerOutputStream encodes negative integer incorrectly
+ */
+import sun.security.util.DerOutputStream;
+
+public class NegInt {
+
+    public static void main(String[] args) throws Exception {
+        DerOutputStream out;
+        out = new DerOutputStream();
+        out.putInteger(-128);
+        if(out.toByteArray().length != 3) {
+            throw new Exception("-128 encode error");
+        }
+        out = new DerOutputStream();
+        out.putInteger(-129);
+        if(out.toByteArray().length != 4) {
+            throw new Exception("-129 encode error");
+        }
+    }
+}