"alter table from MyISAM to MERGE lost data without errors and warnings"
Add new handlerton flag which prevent user from altering table storage
engine to storage engines which would lose data. Both 'blackhole' and
'merge' are marked with the new flag.
Tests included.
no rows of the blackhold engine (for this engine to be a binlog propagator).
NOTE: blackhole.test currently hangs in 5.0 BUG#10175 so I'll merge without running this test; the
person who fixes the hang will correct the merged blackhole.result or ask me to).