[FIX] l10n_account_withholding_tax: partner on journal items

Fixes an issue where the partner is missing from the journal items
generated by the withholding tax on payment system.

closes odoo#220117

X-original-commit: 94a81e0
Signed-off-by: William André (wan) <wan@odoo.com>
Signed-off-by: Nicolas Viseur (vin) <vin@odoo.com>

Author: vin-odoo

addons/l10n_account_withholding_tax/models/account_payment_withholding_line.py

@@ -89,3 +89,6 @@ def _get_valid_liquidity_accounts(self):
             self.payment_id.journal_id.outbound_payment_method_line_ids.payment_account_id |
             self.payment_id.outstanding_account_id
         )
+
+    def _get_comodel_partner(self):
+        return self.payment_id.partner_id

addons/l10n_account_withholding_tax/models/account_withholding_line.py

@@ -381,6 +381,7 @@ def _prepare_withholding_amls_create_values(self):
                 'name': self.env._("WH Tax: %(name)s", name=tax_line_vals['name']),
                 'amount_currency': -tax_line_vals['amount_currency'],
                 'balance': -tax_line_vals['balance'],
+                'partner_id': self._get_comodel_partner().id,
             })
 
         # Aggregate the base lines.
@@ -406,6 +407,7 @@ def _prepare_withholding_amls_create_values(self):
                 'name': self.env._('WH Base: %(names)s', names=', '.join(amounts['names'])),
                 'amount_currency': amounts['amount_currency'],
                 'balance': amounts['balance'],
+                'partner_id': self._get_comodel_partner().id,
             })
             aml_create_values_list.append({
                 **grouping_key,
@@ -415,6 +417,7 @@ def _prepare_withholding_amls_create_values(self):
                 'analytic_distribution': None,
                 'amount_currency': -amounts['amount_currency'],
                 'balance': -amounts['balance'],
+                'partner_id': self._get_comodel_partner().id,
             })
 
         return aml_create_values_list
@@ -532,3 +535,7 @@ def grouping_function(base_line_data, tax_data):
     def _get_valid_liquidity_accounts(self):
         """ Get the valid liquidity accounts for the payment; we need to ensure that the line account does not match any of them. """
         return ()
+
+    def _get_comodel_partner(self):
+        """ Get the partner from the comodel record; in order to have it available when required. """
+        return self.env['res.partner']

addons/l10n_account_withholding_tax/tests/test_account_withholding_flows.py

@@ -1039,3 +1039,32 @@ def test_manual_adjustments(self):
                 line_form.amount = 11
             self.assertEqual(line['base_amount'], 500)
             self.assertEqual(line['amount'], 11)
+
+    def test_partner_is_set_on_lines(self):
+        """ Test that the partner is set on the lines generated by the withholding tax on payment system. """
+        withholding_tax = self.percent_tax(-10, is_withholding_tax_on_payment=True, withholding_sequence_id=self.withholding_sequence.id)
+
+        invoice = self.env['account.move'].create({
+            'move_type': 'out_invoice',
+            'partner_id': self.partner_a.id,
+            'invoice_line_ids': [Command.create({
+                'product_id': self.product_a.id,
+                'price_unit': 1000.0,
+                'tax_ids': [Command.set(withholding_tax.ids)],
+            })],
+        })
+        invoice.action_post()
+        wizard = self.env['account.payment.register']\
+            .with_context(active_model='account.move', active_ids=invoice.ids)\
+            .create({})
+        payment = wizard._create_payments()
+        self.assertRecordValues(payment, [{
+            'amount': 1000.0,
+        }])
+        self.assertRecordValues(payment.move_id.line_ids, [
+            {'balance': 900.0,     'tax_ids': [],                    'partner_id': self.partner_a.id},
+            {'balance': -1000.0,   'tax_ids': [],                    'partner_id': self.partner_a.id},
+            {'balance': 100.0,     'tax_ids': [],                    'partner_id': self.partner_a.id},
+            {'balance': 1000.0,    'tax_ids': withholding_tax.ids,   'partner_id': self.partner_a.id},
+            {'balance': -1000.0,   'tax_ids': [],                    'partner_id': self.partner_a.id},
+        ])

addons/l10n_account_withholding_tax/wizards/account_payment_register_withholding_line.py

@@ -104,3 +104,6 @@ def _get_valid_liquidity_accounts(self):
             self.payment_register_id.journal_id.outbound_payment_method_line_ids.payment_account_id |
             self.payment_register_id.withholding_outstanding_account_id
         )
+
+    def _get_comodel_partner(self):
+        return self.payment_register_id.partner_id