[FIX] base: make country code required

Steps to reproduce:
- Go to Contact-Configuration-Countries
- Remove the code of a country
- Create a new contact
- Select the country from which you deleted the code
- Put any vat number starting with country code you deleted

Issue:
Traceback

Cause:
in `_run_vat_test` we want to `country.code.lower()` -> country code does not exist

Solution:
Prevent the user to delete a country code by making the field required.

sentry-3923412146

closes odoo/odoo#113207

Signed-off-by: William André (wan) <wan@odoo.com>

addons/test_website/tests/test_is_multilang.py

@@ -31,7 +31,7 @@ class TestIsMultiLang(odoo.tests.HttpCase):
         it = self.env.ref('base.lang_it').sudo()
         en = self.env.ref('base.lang_en').sudo()
         be = self.env.ref('base.lang_fr_BE').sudo()
-        country1 = self.env['res.country'].create({'name': "My Super Country"})
+        country1 = self.env['res.country'].create({'name': "My Super Country", 'code': 'ZV'})
 
         it.active = True
         be.active = True

odoo/addons/base/models/res_country.py

@@ -38,6 +38,7 @@ class Country(models.Model):
         string='Country Name', required=True, translate=True)
     code = fields.Char(
         string='Country Code', size=2,
+        required=True,
         help='The ISO country code in two chars. \nYou can use this field for quick search.')
     address_format = fields.Text(string="Layout in Reports",
         help="Display format to use for addresses belonging to this country.\n\n"

odoo/addons/base/tests/test_form_create.py

@@ -64,6 +64,7 @@ class TestFormCreate(TransactionCase):
     def test_create_res_country(self):
         country_form = Form(self.env['res.country'])
         country_form.name = 'a country'
+        country_form.code = 'ZX'
         country_form.save()
 
     def test_create_res_lang(self):

odoo/addons/base/tests/test_orm.py

@@ -45,13 +45,13 @@ class TestORM(TransactionCase):
         self.assertTrue(type(Model).display_name.automatic, "test assumption not satisfied")
 
         # access regular field when another record from the same prefetch set has been deleted
-        records = Model.create([{'name': name} for name in ('Foo', 'Bar', 'Baz')])
+        records = Model.create([{'name': name[0], 'code': name[1]} for name in (['Foo', 'ZV'], ['Bar', 'ZX'], ['Baz', 'ZY'])])
         for record in records:
             record.name
             record.unlink()
 
         # access computed field when another record from the same prefetch set has been deleted
-        records = Model.create([{'name': name} for name in ('Foo', 'Bar', 'Baz')])
+        records = Model.create([{'name': name[0], 'code': name[1]} for name in (['Foo', 'ZV'], ['Bar', 'ZX'], ['Baz', 'ZY'])])
         for record in records:
             record.display_name
             record.unlink()
@@ -285,12 +285,14 @@ class TestORM(TransactionCase):
                 Command.create({'name': 'West Foo', 'code': 'WF'}),
                 Command.create({'name': 'East Foo', 'code': 'EF'}),
             ],
+            'code': 'ZV',
         }, {
             'name': 'Bar',
             'state_ids': [
                 Command.create({'name': 'North Bar', 'code': 'NB'}),
                 Command.create({'name': 'South Bar', 'code': 'SB'}),
             ],
+            'code': 'ZX',
         }]
         foo, bar = self.env['res.country'].create(vals_list)
         self.assertEqual(foo.name, 'Foo')

odoo/addons/base/tests/test_res_partner.py

@@ -193,7 +193,7 @@ class TestPartner(TransactionCase):
     def test_display_address_missing_key(self):
         """ Check _display_address when some keys are missing. As a defaultdict is used, missing keys should be
         filled with empty strings. """
-        country = self.env["res.country"].create({"name": "TestCountry", "address_format": "%(city)s %(zip)s"})
+        country = self.env["res.country"].create({"name": "TestCountry", "address_format": "%(city)s %(zip)s", "code": "ZV"})
         partner = self.env["res.partner"].create({
             "name": "TestPartner",
             "country_id": country.id,

odoo/addons/base/tests/test_search.py

@@ -166,7 +166,7 @@ class test_search(TransactionCase):
             'ttype': 'boolean',
         })
         self.assertEqual('x_active', model_country._active_name)
-        country_ussr = model_country.create({'name': 'USSR', 'x_active': False})
+        country_ussr = model_country.create({'name': 'USSR', 'x_active': False, 'code': 'ZV'})
         ussr_search = model_country.search([('name', '=', 'USSR')])
         self.assertFalse(ussr_search)
         ussr_search = model_country.with_context(active_test=False).search([('name', '=', 'USSR')])

odoo/addons/test_new_api/tests/test_new_fields.py

@@ -661,8 +661,9 @@ class TestFields(TransactionCaseWithUserDemo):
 
     def test_13_inverse_with_unlink(self):
         """ test x2many delete command combined with an inverse field """
-        country1 = self.env['res.country'].create({'name': 'test country'})
-        country2 = self.env['res.country'].create({'name': 'other country'})
+
+        country1 = self.env['res.country'].create({'name': 'test country', 'code': 'ZV'})
+        country2 = self.env['res.country'].create({'name': 'other country', 'code': 'ZX'})
         company = self.env['res.company'].create({
             'name': 'test company',
             'child_ids': [

odoo/addons/test_new_api/tests/test_schema.py

@@ -254,7 +254,7 @@ class TestSchema(common.TransactionCase):
     def test_10_char(self):
         """ check the database representation of a char field """
         model = self.env['res.country']
-        self.assertFalse(type(model).code.required)
+        self.assertTrue(type(model).code.required)
         self.assertEqual(type(model).code.size, 2)
         columns_data = self.get_columns_data(model._table)
         self.assertEqual(columns_data['code'], {
@@ -263,7 +263,7 @@ class TestSchema(common.TransactionCase):
             'column_name': u'code',
             'data_type': u'character varying',
             'datetime_precision': None,
-            'is_nullable': u'YES',
+            'is_nullable': u'NO',
             'is_updatable': u'YES',
             'numeric_precision': None,
             'numeric_precision_radix': None,