Bugfix for 53290, fast unique index creation fails on duplicate null values
Summary:
Bug in the fast index creation code incorrectly considers null
values to be duplicates during block merging. Innodb policy is that
multiple null values are allowed in a unique index. Null duplicates
were correctly ignored while sorting individual blocks and with slow
index creation.
Test Plan:
mtr, including new test, load dbs using deferred index creation
DiffCamp Revision: 110840
Reviewed By: mcallaghan
CC: mcallaghan, mysql-devel@lists
Revert Plan:
OK