From 9ea17019f6891a8036aac9e87b6f636f921e486c Mon Sep 17 00:00:00 2001
From: Victor Feyens <vfe@odoo.com>
Date: Thu, 14 Dec 2023 15:06:18 +0100
Subject: [PATCH] [FIX] core: default multi-company domain

of check_company=True fields.

Suppose two models

class A:

    company_id = fields.M2O() # not required

class B:
    _check_company_auto = True

    company_id = fields.M2O() # not required
    a_id = fields.M20(check_company=True)

and the following code:

a = A.create({'company_id': 1})
b = B.create({'a_id': a.id, 'company_id': False})

The creation of B will fail because of the multi-company
checks, which is expected.

Nevertheless, since 0d30cc2bc9b9cc2b805d6c2d0a440f185c648da0, the domain
of the field a_id would be:

(company_id and ['|', ('company_id', '=', False), ('company_id', 'in', [company_id])] or []) + ([])

which means that through the interface, if you create a record b following
the example above (no company_id on b), the evaluated domain would be empty,
allowing to select records of class A, even if they belong to another company.
Of course, this would lead to a multi-company error when trying to save the
record.

This commit makes sure that the right domain is applied on
check_company=True fields, even if the current record has no value
in its `company_id` field.

opw-3629374

closes odoo/odoo#151341

X-original-commit: aaddedc3bab4f16747fb0f71ae626d94f3975ee3
Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>
---
 odoo/addons/base/models/res_users.py | 6 ++++--
 odoo/fields.py                       | 3 ++-
 odoo/models.py                       | 2 ++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/odoo/addons/base/models/res_users.py b/odoo/addons/base/models/res_users.py
index 9e7e65cec9d..9308aaf71f7 100644
--- a/odoo/addons/base/models/res_users.py
+++ b/odoo/addons/base/models/res_users.py
@@ -280,8 +280,10 @@ class Users(models.Model):
     _order = 'name, login'
     _allow_sudo_commands = False
 
-    def _check_company_domain(self, companies=None):
-        return [('company_ids', 'in', models.to_company_ids(companies))] if companies else []
+    def _check_company_domain(self, companies):
+        if not companies:
+            return []
+        return [('company_ids', 'in', models.to_company_ids(companies))]
 
     @property
     def SELF_READABLE_FIELDS(self):
diff --git a/odoo/fields.py b/odoo/fields.py
index 4baede645ad..04083a0cfe4 100644
--- a/odoo/fields.py
+++ b/odoo/fields.py
@@ -2925,7 +2925,8 @@ class _Relational(Field):
             else:
                 cid = "id" if self.model_name == "res.company" else "company_id"
             company_domain = env[self.comodel_name]._check_company_domain(companies=unquote(cid))
-            return f"({cid} and {company_domain} or []) + ({domain or []})"
+            no_company_domain = env[self.comodel_name]._check_company_domain(companies='')
+            return f"({cid} and {company_domain} or {no_company_domain}) + ({domain or []})"
         return domain
 
 
diff --git a/odoo/models.py b/odoo/models.py
index 79eb7f9d35a..1a77dd270e2 100644
--- a/odoo/models.py
+++ b/odoo/models.py
@@ -4000,6 +4000,8 @@ class BaseModel(metaclass=MetaModel):
         :param companies: the allowed companies for the related record
         :type companies: BaseModel or list or tuple or int or unquote
         """
+        if not companies:
+            return [('company_id', '=', False)]
         return ['|', ('company_id', '=', False), ('company_id', 'in', to_company_ids(companies))]
 
     def _check_company(self, fnames=None):