FULL PRODUCT VERSION :
java version "1.6.0_31"
Java(TM) SE Runtime Environment (build 1.6.0_31-b05)
Java HotSpot(TM) Client VM (build 20.6-b01, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
I have created a SPNEGO security context and except appropriate tokens. Though the client sent me a Kerberos 5 token which of course will be rejected. GssContext#acceptSecContext throws an exception with following message:

> GSSException: No credential found for: 1.2.840.113554.1.2.21.2.840.113554.1.2.2 usage: Accept

The mech is printed TWICE.

It should be:
GSSException: No credential found for: 1.2.840.113554.1.2.2 usage: Accept

This bug can be easily fixed in JDK 6 and 7 by editing:
sun.security.jgss.GSSCredentialImpl

Changing throw new GSSExceptionImpl(GSSException.NO_CRED,
                                       "No credential found for: " +
                                       mechOid + getElementStr(mechOid,
                                       initiate? INITIATE_ONLY : ACCEPT_ONLY));

to throw new GSSExceptionImpl(GSSException.NO_CRED,
                                       "No credential found for: " +
                                       getElementStr(mechOid,
                                       initiate? INITIATE_ONLY : ACCEPT_ONLY));


REPRODUCIBILITY :
This bug can be reproduced always.