[FIX] core: convert_to_write() of x2many field with new records

When comparing the values of a new record with its origin, x2many fields
are always different because we compare new records with real records.
For instance, converting the value of a one2many field where lines have
a many2many field always returns update commands for the many2many
field.

closes odoo/odoo#66937

X-original-commit: 03a4137cc3fa398dbd0cb214dc5472a083ae33b8
Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/odoo/addons/test_new_api/tests/test_new_fields.py b/odoo/addons/test_new_api/tests/test_new_fields.py
index 3efb67ce3e2..5a50f5b2b18 100644
--- a/odoo/addons/test_new_api/tests/test_new_fields.py
+++ b/odoo/addons/test_new_api/tests/test_new_fields.py
@@ -1651,6 +1651,16 @@ class TestFields(TransactionCaseWithUserDemo):
         self.assertNotEqual(new_disc.participants, disc.participants)
         self.assertEqual(new_disc.participants._origin, disc.participants)
 
+        # check convert_to_write
+        tag = self.env['test_new_api.multi.tag'].create({'name': 'Foo'})
+        rec = self.env['test_new_api.multi'].create({
+            'lines': [(0, 0, {'tags': [(6, 0, tag.ids)]})],
+        })
+        new = rec.new(origin=rec)
+        self.assertEqual(new.lines.tags._origin, rec.lines.tags)
+        vals = new._convert_to_write(new._cache)
+        self.assertEqual(vals['lines'], [(6, 0, rec.lines.ids)])
+
     def test_41_new_compute(self):
         """ Check recomputation of fields on new records. """
         move = self.env['test_new_api.move'].create({