[FIX] sale: post processing issues when creating invoices

Before this commit, when the automatic invoice setting is enabled, a
traceback would be shown when customers pay and the post-processing of
the transaction tries to create an invoice. The problem is that the
 invoice is created in sudo, but it's unsudoed before logging invoices
in the chatter.

Now, the invoice will stay sudoed if the method is called in sudo.

opw-3700576

closes odoo/odoo#157779

Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

addons/sale/wizard/sale_make_invoice_advance.py

@@ -221,7 +221,7 @@ class SaleAdvancePaymentInv(models.TransientModel):
 
             invoice = self.env['account.move'].sudo().create(
                 self._prepare_invoice_values(order, down_payment_lines)
-            ).with_user(self.env.uid)  # Unsudo the invoice after creation
+            )
 
             # Ensure the invoice total is exactly the expected fixed amount.
             if self.advance_payment_method == 'fixed':
@@ -256,6 +256,9 @@ class SaleAdvancePaymentInv(models.TransientModel):
                                 line_commands.append(Command.update(line.id, {attr: line[attr] + amt * sign}))
                         invoice.line_ids = line_commands
 
+            # Unsudo the invoice after creation if not already sudoed
+            invoice = invoice.sudo(self.env.su)
+
             poster = self.env.user._is_internal() and self.env.user.id or SUPERUSER_ID
             invoice.with_user(poster).message_post_with_source(
                 'mail.message_origin_link',