[14.0][FIX] l10n_it_withholding_tax pagamento con spese

l10n_it_withholding_tax/wizards/account_payment_register.py

@@ -1,7 +1,7 @@
 #  Copyright 2023 Simone Rubino - TAKOBI
 #  License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
 
-from odoo import api, models
+from odoo import api, fields, models
 from odoo.tools import float_is_zero
 
 
@@ -38,3 +38,22 @@ def _inject_withholding_net_pay_residual(self, wizard_values_from_batch):
                         "source_amount_currency"
                     ] = net_pay_residual_amount
         return wizard_values_from_batch
+
+    @api.depends('amount')
+    def _compute_payment_difference(self):
+        super()._compute_payment_difference()
+        for wizard in self:
+            withholding_amount = sum(
+                wizard.mapped("line_ids.withholding_tax_amount") or [])
+            if wizard.source_currency_id == wizard.currency_id:
+                # Same currency, probably the only needed here.
+                wizard.payment_difference = (
+                    wizard.source_amount_currency - withholding_amount - wizard.amount)
+            elif wizard.currency_id == wizard.company_id.currency_id:
+                # probably not needed as withholding amount does not know currency
+                # Payment expressed on the company's currency.
+                wizard.payment_difference = (
+                    wizard.source_amount - withholding_amount - wizard.amount)
+            # not supported from withholding:
+            # Foreign currency on payment different from the one set on the journal
+            # entries.