pull up r20222 from trunk

pull up r20222 from trunk

 r20222@cathode-dark-space:  tlyu | 2008-02-07 02:07:06 -0500
 ticket: new
 target_version: 1.6.4
 tags: pullup
 subject: more tests for libdb btree page split on zero index
 component: krb5-kdc

 Enhance btree debugging output somewhat to limit key printout to the
 key length if the key is not null-terminated.

 Add additional test case for the zero-index page split bug; test case
 can create a corrupted btree database with records unreachable by
 random access but reachable by sequential access.  Requires
 recompiling with CPPFLAGS='-DDEBUG -DDEBUG_IDX0SPLIT' to correctly
 model mpool page reuse that would be present in production conditions.
 (CPPFLAGS=-DDEBUG would otherwise explicitly overwrite the contents of
 reused pages.)

ticket: 5888
version_fixed: 1.6.4

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-6@20233 dc483132-0cff-0310-8789-dd5450dbe970