Pull up r25660 from trunk

Pull up r25660 from trunk

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 r25660 | ghudson | 2012-01-26 16:56:16 -0500 (Thu, 26 Jan 2012) | 22 lines

 ticket: 7082
 subject: Various lookaside cache fixes
 target_version: 1.10
 tags: pullup

 Don't touch the lookaside cache if we're responding with a lookaside
 cache entry.  Also, leave the null entry behind if we're deliberately
 dropping a request (a rare case) so that we don't have to process it
 again.  Fixes several lookaside problems in 1.10:

 * When dropping a request because it was already being processed, we
   were erroneously removing the null entry, causing us to process the
   request again upon a second retransmit.

 * When responding to a finished request with a lookaside entry, we
   were removing and re-adding the entry to the cache, resetting its
   time and performing unnecessary work.

 * We were not caching responses we couldn't deliver because they were
   too big for UDP, causing us to re-process the request when it came
   in again via TCP instead of simply delivering the cached response.

ticket: 7082
version_fixed: 1.10.1
status: resolved

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-10@25681 dc483132-0cff-0310-8789-dd5450dbe970