Reading from a self-logging engine and updating a transactional engine such as Innodb
generates changes that are written to the binary log in the statement format and may
make slaves diverge. In the mixed mode, such changes should be written to the binary
log in the row format.

Note that the issue does not happen if we mix a self-logging engine and MyIsam
as this case is caught by checking the mixture of non-transactional and transactional
engines.

So, we classify a mixed statement where one reads from NDB and writes into another 
engine as unsafe:

if (multi_engine && flags_some_set & HA_HAS_OWN_BINLOGGING)
  lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE);