Original revision is from mysql-6.0-codebase:

revno: 2630.3.1
committer: Alexander Nozdrin <alik@mysql.com>
branch nick: 6.0-rt-bug26704
timestamp: Thu 2008-05-29 21:04:06 +0400
message:
  A fix for Bug#26704: Failing DROP DATABASE brings
  mysql-client out of sync.

  The problem was that we changed current database w/o caring
  whether it was dropped successfully or not.

  The fix is not to change current database if we failed to drop it.