In the normal course of saving-action, readonly fields are stripped
out when sending data to the server. The SSF would reuse the same code
when "saving" O2M lines to the parent record however that is not
correct and would lead to misbehaving views as readonly (non-stored)
fields used as "transients" (storing data within the extent of a
record's edition session) would not behave properly.
Fix by overriding the O2M Form's save so that readonly fields are
kept and stored in the parent record.
Closes#23620
Useful to better test business flows & replace yaml test files:
instantiating records & calling onchanges by hand is very
error-prone (it's easy to miss onchanges, or to manually set fields
which can't be set through the view we're interested in, ...)
odoo.tests.common.Form implements the basic *creation*
flow (fields_get, default_get, onchange) up to saving the record,
including proper handling of the required and readonly modifiers &
their domains.
* edition of existing records, including filtering out unmodified
fields when saving
* possibly buttons
* ensuring the API is convenient
Laurent Smet