Because method _read() no longer updates existing values in memory,
those values in memory must be consistent with the database.
On the other hand, if pending updates are not performed on the database
before fetching values, it means that the corresponding database values
cannot be put in cache. This implies that one cannot empty the cache
without flushing the corresponding fields.
In order to avoid mistakes, flush automatically before invalidating the
cache. This makes the invalidation methods safe by default, and avoids
cargo-culting which would systematically associate invalidation to
flushing, which may eventually be less performant.
Part-of: odoo/odoo#66938
Raphael Collet
9c3b9a4926