Let's assume the following scenario with 'purchase_product_matrix'
module installed:
 - create a new Purchase Order
 - add a line in the one2many
 - select "Customizable desk" as product
 - [the desk matrix opens]
 - close the matrix
 - select "Conference chair" instead
 - [the desk matrix opens, whereas it should be the chair one]

It didn't work because of a small bug in the FieldOne2Many. This
field is configured to be reset when any other field in the view
changes. The product configurator feature relies on that. However,
when another field changes, the One2Many didn't update its internal
state with the new record (and it skipped the rendering, which is
fine). The matrix product configurator thus read an obsolete value
in the internal of the one2many.

Since the internal state is now always up-to-date, we can directly
read there the grid information, instead of looking inside other
fields that have been updated (attempt done in [1])

It would be nice to rethink the whole product configurator stuff
in master, to make it more robust, maybe when converting it to owl?

[1] https://github.com/odoo/odoo/commit/21bcafc053be7f80eed7a684fee2dc1e3caaafa5

opw~2421798

closes odoo/odoo#64552

Signed-off-by: Géry Debongnie (ged) <ged@openerp.com>

Probably since recent js framework changes, when trying
to modify the matrix of a product on a new SO (not saved),
a js error was raised (wrong qweb template rendering).

This is due to a wrong check when loading the matrix data,
in the case of a new record, the data wasn't correctly updated
on all widgets, resulting in an opening of the matrix with the results
of the last matrix changes (since the information is transferred in the same field).

This commit:

* Ensures that the correct data is taken to open the matrix (solving the main
problem of matrix update on new records)
* Improves test coverage to cover untested buggy situation
* Fixes another error found while improving test coverage:
The edition of existing quantities was wrongly creating new lines, instead of updating
existing ones.  Simplify lines comparison to ensure the matrix won't generate two lines
for the same variant combination.

closes odoo/odoo#54917

Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

X-original-commit: 127a75ed5c746291f9b0b7466d8935c83abc32a0

X-original-commit: 44462e11ddba648d64fb75997e3f87a877c642eb