[FIX] fields: setting a one2many field deletes all its lines (#13082)

Setting the value of a one2many field (`rec.line_ids = ...`) converts the new
recordset to a list of commands, and passes it to `write`.

Currently the list of commands is like: `[(5,), (0, 0, vals), (1, id, vals), (4, id), ...]`.
Notice that the command `(5,)` is inappropriate here: it deletes all the
existing lines of the record. Reintroducing the same lines with `(4, id)`
commands crashes, because the corresponding `id` is no longer in database.

The fix serializes the recordset as a list of commands like
`[(6, 0, ids), (0, 0, vals), (1, id, vals), ...]`.
Only the lines that are not kept will be deleted in this case.

0 files changed, 0 insertions, 0 deletions