Fix RelationToMany calling undefined fonction.

tests/test_relation.py

@@ -17,9 +17,10 @@
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 ##############################################################################
+from typing import Any
 
 from odoo import tests
 
 from odoo.addons.converter import (
     Field,
     Model,
@@ -20,9 +21,10 @@
 
 from odoo import tests
 
 from odoo.addons.converter import (
     Field,
     Model,
+    RelationToMany,
     RelationToOne,
     Skip,
     Xref,
@@ -117,3 +119,50 @@
         message_to_odoo(self.env, message, self.env["res.users"], converter)
         self.assertEqual(user.partner_id, new_partner)
         self.assertEqual(new_partner.color, 3)
+
+    def test_many2many_to_odoo(self):
+        """Ensure multiple sub-objects linked from the main one gets updated
+        when Odoo receives a message.
+        """
+
+        # This converter wraps a user and adds info from its related partner.
+        converter = Model(
+            None,
+            {
+                "users": RelationToMany(
+                    "user_ids",
+                    "res.users",
+                    Model(
+                        "user",
+                        {
+                            "email": Field("email"),
+                            "xref": Xref("base"),
+                        },
+                    ),
+                ),
+                "xref": Xref("base"),
+            },
+        )
+
+        partner = self.env.ref("base.main_partner")
+        self.assertFalse(partner.user_ids)
+
+        # Run our message reception.
+        message: dict[str, Any] = {
+            "users": [
+                {
+                    "__type__": "user",
+                    "xref": "user_admin",
+                },
+                {
+                    "__type__": "user",
+                    "xref": "user_demo",
+                },
+            ],
+            "xref": "main_partner",
+        }
+        message_to_odoo(self.env, message, self.env["res.partner"], converter)
+
+        # Check the partner's users
+        self.assertTrue(partner.user_ids)
+        self.assertEqual(len(partner.user_ids), 2)