[FIX] base: returning a domain from an onchange

Turns out we've got an operator just for the pattern of "match value
if there's one, otherwise match everything".

Also remove an example of domain in onchange doc.

closes odoo/odoo#40938

Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>

2 files changed, 4 insertions, 6 deletions

diff --git a/odoo/addons/base/models/res_company.py b/odoo/addons/base/models/res_company.py
index 84e4468850d..9731779dfdc 100644
--- a/odoo/addons/base/models/res_company.py
+++ b/odoo/addons/base/models/res_company.py
@@ -81,7 +81,10 @@ class Company(models.Model):
     street2 = fields.Char(compute='_compute_address', inverse='_inverse_street2')
     zip = fields.Char(compute='_compute_address', inverse='_inverse_zip')
     city = fields.Char(compute='_compute_address', inverse='_inverse_city')
-    state_id = fields.Many2one('res.country.state', compute='_compute_address', inverse='_inverse_state', string="Fed. State")
+    state_id = fields.Many2one(
+        'res.country.state', compute='_compute_address', inverse='_inverse_state',
+        string="Fed. State", domain="[('country_id', '=?', country_id)]"
+    )
     bank_ids = fields.One2many('res.partner.bank', 'company_id', string='Bank Accounts', help='Bank accounts related to this company')
     country_id = fields.Many2one('res.country', compute='_compute_address', inverse='_inverse_country', string="Country")
     email = fields.Char(related='partner_id.email', store=True, readonly=False)
@@ -173,13 +176,9 @@ class Company(models.Model):
 
     @api.onchange('country_id')
     def _onchange_country_id_wrapper(self):
-        res = {'domain': {'state_id': []}}
-        if self.country_id:
-            res['domain']['state_id'] = [('country_id', '=', self.country_id.id)]
         values = self.on_change_country(self.country_id.id)['value']
         for fname, value in values.items():
             setattr(self, fname, value)
-        return res
 
     @api.model
     def _name_search(self, name, args=None, operator='ilike', limit=100, name_get_uid=None):
diff --git a/odoo/api.py b/odoo/api.py
index ebda349fe61..68b92943640 100644
--- a/odoo/api.py
+++ b/odoo/api.py
@@ -148,7 +148,6 @@ def onchange(*args):
     .. code-block:: python
 
         return {
-            'domain': {'other_id': [('partner_id', '=', partner_id)]},
             'warning': {'title': "Warning", 'message': "What is this?", 'type': 'notification'},
         }