--- a/jdk/src/share/classes/sun/security/jgss/spnego/SpNegoContext.java	Thu Sep 26 18:20:25 2013 -0700
+++ b/jdk/src/share/classes/sun/security/jgss/spnego/SpNegoContext.java	Fri Sep 27 15:25:18 2013 +0800
@@ -525,6 +525,10 @@
 
                 // get the mechanism token
                 byte[] mechToken = initToken.getMechToken();
+                if (mechToken == null) {
+                    throw new GSSException(GSSException.FAILURE, -1,
+                            "mechToken is missing");
+                }
 
                 /*
                  * Select the best match between the list of mechs

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/sun/security/jgss/spnego/MechTokenMissing.java	Fri Sep 27 15:25:18 2013 +0800
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2013, 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 8024861
+ * @summary Incomplete token triggers GSS-API NullPointerException
+ */
+
+import org.ietf.jgss.GSSContext;
+import org.ietf.jgss.GSSCredential;
+import org.ietf.jgss.GSSException;
+import org.ietf.jgss.GSSManager;
+
+public class MechTokenMissing {
+    public static void main(String[] args) throws Exception {
+        GSSCredential cred = null;
+        GSSContext ctx = GSSManager.getInstance().createContext(cred);
+
+        String var =
+            /*0000*/ "60 1C 06 06 2B 06 01 05 05 02 A0 12 30 10 A0 0E " +
+            /*0010*/ "30 0C 06 0A 2B 06 01 04 01 82 37 02 02 0A ";
+        byte[] token = new byte[var.length()/3];
+        for (int i=0; i<token.length; i++) {
+            token[i] = Integer.valueOf(var.substring(3*i,3*i+2), 16).byteValue();
+        }
+        try {
+            ctx.acceptSecContext(token, 0, token.length);
+        } catch (GSSException gsse) {
+            System.out.println("Expected exception: " + gsse);
+        }
+    }
+}