Push the patch of Jan Lindstrom: better comments
ha_innodb.cc:
  Partial fix for Bug #12263 : we let InnoDB always to perform a rollback on the trx object if MySQL closes a connection; but we do print a warning to the .err log if an InnoDB transaction was active; we may remove that print later, since the situation really is not a bug; MySQL just is not aware that some cursor operation started an InnoDB transaction