[FIX] account,payment: instant payment post process

Fine-tuning of commit dd8494313f

closes odoo/odoo#32124

Signed-off-by: Lucas Perais (lpe) <lpe@odoo.com>

addons/account/models/account_payment.py

@@ -661,9 +661,7 @@ class account_payment(models.Model):
         if any(len(record.invoice_ids) != 1 for record in self):
             # For multiple invoices, there is account.register.payments wizard
             raise UserError(_("This method should only be called to process a single invoice's payment."))
-        res = self.post()
-        self.mapped('payment_transaction_id').filtered(lambda x: x.state == 'done' and not x.is_processed)._post_process_after_done()
-        return res
+        return self.post()
 
     def _create_payment_entry(self, amount):
         """ Create a journal entry corresponding to a payment, if the payment references invoice(s) they are reconciled.

addons/payment/models/account_payment.py

@@ -71,6 +71,11 @@ class AccountPayment(models.Model):
 
         return transactions
 
+    def action_validate_invoice_payment(self):
+        res = super(AccountPayment, self).action_validate_invoice_payment()
+        self.mapped('payment_transaction_id').filtered(lambda x: x.state == 'done' and not x.is_processed)._post_process_after_done()
+        return res
+
     @api.multi
     def post(self):
         # Post the payments "normally" if no transactions are needed.