In spnego_gss_ctx_id_rec, store the set of negotiable mechanisms as
well as the currently selected internal_mech, which becomes an alias
into mech_set.  In init_ctx_reselect, locate the acceptor's counter-
proposal in sc->mech_set and consider the token defective if it is not
found.

https://github.com/krb5/krb5/commit/91e4a3f5db32febb8b95706e4ec3d4642b02b446
Commit By: ghudson
Revision: 25590
Changed Files:
U   trunk/src/lib/gssapi/spnego/gssapiP_spnego.h
U   trunk/src/lib/gssapi/spnego/spnego_mech.c