During the UPDATE of PRIMARY KEY columns, we may miscalculate the
size of the clustered index record.
row_upd_clust_rec_by_insert(): Pass the total number of off-page columns,
which may include such columns that were inherited from the record
and not created as part of the UPDATE operation.
This is based on
mysql/mysql-server@490c45e8c8
which is a follow-up to
mysql/mysql-server@1fa475b85d
which we filed and fixed as MDEV-21511.
No test case was provided by Oracle.
2644e52fdb