The ORM doesn't automatically link subrecords when it receives an
update command for a one2many. However, it may be necessary when
the default_get returns existing records for a one2many field. It
only worked before this rev. for the hr_expense model because of an
hack from 2016 (to reproduce: go to Expenses, check some expenses
from the list view, in Actions, click on 'Submit to Manager', the
new hr_expense_sheet contains the checked expenses (one2many), and
the webclient only sent an update command by linked subrecord).
This rev. fixes the problem properly: when the default_get returns
existing subrecords for a one2many field, a link_to command (4) is
generated alongside the update (1) command.
Aaron Bohy
7b8001a847