pull up r22369 from trunk

pull up r22369 from trunk

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 r22369 | ghudson | 2009-05-24 17:53:51 +0200 (Sun, 24 May 2009) | 11 lines

 ticket: 6496
 subject: Fix vector initialization error in KDC preauth code
 target_version: 1.7
 tags: pullup

 In the KDC, get_preauth_hint_list had two bugs initializing the
 preauth array.  It was allocating 21 extra entries instead of two due
 to a typo (harmless), and it was only zeroing up through one extra
 entry (harmful).  Adjust the code to use calloc to avoid further
 disagreements of this nature.

ticket: 6496
version_fixed: 1.7

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-7@22377 dc483132-0cff-0310-8789-dd5450dbe970