Problem was that the mix of handlers was not consistent between
CREATE and ALTER
changed so that it works like:
- All partitions must use the same engine
AND it must be the same as the table.
- if one does NOT specify an engine on the table level
then one must either NOT specify any engine on any
partition/subpartition OR for ALL partitions/subpartitions
Note: that after a table have been created, the storage engine
is specified for all parts of the table (table/partition/subpartition)
and so when using alter, one does not need to specify it (unless one
wants to change the storage engine, then one have to specify it on the
table level)
Problem: when alter to partitioned table,
it does not see it as change of engine.
Solution: If alter includes partitioning, check if it is possible
to change engines (eg. is the table referenced by a FK)
Before the fix:
ha_partition objects had ha_partition::m_part_info==NULL and that caused
crash
After:
- The new ha_partition::clone() function makes the clones use parent's
m_part_info value.
- The parent ha_partition object remains responsible for deallocation of
m_part_info.
