krb5_dbe_lookup_mkvno assumes an mkvno of 1 for entries with no
explicit tl_data.  We've seen at least one pre-1.7 KDB with a master
kvno of 0, violating this assumption.  Fix this as follows:

* krb5_dbe_lookup_mkvno outputs 0 instead of 1 if no tl_data exists.
* A new function krb5_dbe_get_mkvno translates this 0 value to the
  minimum version number in the mkey_list.  (krb5_dbe_lookup_mkvno
  cannot do this as it doesn't take the mkey_list as a parameter.)
* Call sites to krb5_dbe_lookup_mkvno are converted to
  krb5_dbe_get_mkvno, except for an LDAP case where it is acceptable
  to store 0 if the mkvno is unknown.


https://github.com/krb5/krb5/commit/f0e084261aec6be2d508b33f960d38d19f0d0345
Commit By: ghudson
Revision: 23676
Changed Files:
U   trunk/src/include/kdb.h
U   trunk/src/kadmin/dbutil/kdb5_mkey.c
U   trunk/src/lib/kadm5/srv/svr_principal.c
U   trunk/src/lib/kdb/kdb5.c
U   trunk/src/lib/kdb/libkdb5.exports