[18.0][FIX] partner_firstname: res.partner name_create("") fails

[amh-mw]

The name field constraint in core Odoo only requires that name IS NOT NULL, allowing an empty string.

This causes unit tests to fail for the main Odoo mail module:

2025-10-05 17:03:43,999 1 ERROR odoo odoo.addons.mail.tests.test_res_partner: ERROR: Subtest TestPartner.test_name_create_corner_cases (sample='', login='admin')
Traceback (most recent call last):
  File "<decorator-gen-130>", line 2, in test_name_create_corner_cases
  File "/usr/lib/python3/dist-packages/odoo/tests/common.py", line 2344, in _users
    func(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/odoo/addons/mail/tests/test_res_partner.py", line 508, in test_name_create_corner_cases
    self.env['res.partner'].name_create(sample)[0]
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/odoo/addons/base/models/res_partner.py", line 937, in name_create
    partner = self.create(create_values)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<decorator-gen-174>", line 2, in create
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 497, in _model_create_multi
    return create(self, [arg])
           ^^^^^^^^^^^^^^^^^^^
  File "/usr/local/src/metricwise/oca/partner-contact/partner_firstname/models/res_partner.py", line 84, in create
    ).create([vals])
      ^^^^^^^^^^^^^^
  File "<decorator-gen-23>", line 2, in create
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 498, in _model_create_multi
    return create(self, arg)
           ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/odoo/addons/base/models/res_partner.py", line 806, in create
    partners = super().create(vals_list)
               ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<decorator-gen-57>", line 2, in create
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 498, in _model_create_multi
    return create(self, arg)
           ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/odoo/addons/mail/models/mail_thread.py", line 278, in create
    threads = super(MailThread, self).create(vals_list)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<decorator-gen-0>", line 2, in create
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 498, in _model_create_multi
    return create(self, arg)
           ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/odoo/models.py", line 5033, in create
    records = self._create(data_list)
              ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/odoo/models.py", line 5291, in _create
    records._validate_fields(name for data in data_list for name in data['stored'])
  File "/usr/lib/python3/dist-packages/odoo/models.py", line 1631, in _validate_fields
    check(self)
  File "/usr/local/src/metricwise/oca/partner-contact/partner_firstname/models/res_partner.py", line 261, in _check_name
    raise exceptions.EmptyNamesError(record, self.env)
odoo.addons.partner_firstname.exceptions.EmptyNamesError: ("Error(s) with partner 818's name.", 'No name is set.')

[github-actions]

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[github-actions]

There hasn't been any activity on this pull request in the past 4 months, so it has been marked as stale and it will be closed automatically if no further activity occurs in the next 30 days.
If you want this PR to never become stale, please ask a PSC member to apply the "no stale" label.

[amh-mw]

Rebasing, but it seems like #2280 has attempted to solve a similar problem. Investigating...