Fixed a bug: a join could result in a seg fault in copying of a BLOB or
TEXT column if some of the BLOB or TEXT columns in the table contained
SQL NULL values.
Fixed a bug: if you added self-referential foreign key constraints with
ON DELETE CASCADE to tables and a row deletion caused InnoDB
to attempt the deletion of the same row twice because of
a cascading delete, then you got an assertion failure.
Fixed a bug: if you use MySQL 'user level locks' and close
a connection, then InnoDB may assert in ha_innobase.cc, line 302.