[FIX] account: lock posted entry issue with cash rounding

- Enable Cash Rounding in settings.
- Create the cash rounding as
  - Rounding precision: 5.00
  - Rounding Strategy: Add a rounding line
  - Profit Account: Any
  - Loss Account: Any
  - Rounding Method: Half-up
- Enable "Lock Posted Entries with Hash" on Customer Invoices Journal.
- Create a draft invoice and set the cash rounding on it.
- Confirm

Error will raise
You cannot edit the following fields: Account, Label, Partner.
The following entries are already hashed

This occurs because cash rounding is recomputed during post,
after hash was written

opw-3235377

closes odoo/odoo#119126

X-original-commit: 5cb044dd8a2385c9a3c09520ed97eb4faa39216d
Signed-off-by: William André (wan) <wan@odoo.com>

addons/account/models/account_move.py

@@ -1990,6 +1990,12 @@ class AccountMove(models.Model):
             # self.line_ids -= existing_cash_rounding_line
             return
 
+        # No update needed
+        if existing_cash_rounding_line \
+            and existing_cash_rounding_line.balance == diff_balance \
+            and existing_cash_rounding_line.amount_currency == diff_amount_currency:
+            return
+
         _apply_cash_rounding(self, diff_balance, diff_amount_currency, existing_cash_rounding_line)
 
     @contextmanager

addons/account/tests/test_account_inalterable_hash.py

@@ -1,6 +1,7 @@
 from odoo.addons.account.tests.common import AccountTestInvoicingCommon
 from odoo.models import Model
 from odoo.tests import tagged
+from odoo.tests.common import Form
 from odoo import fields
 from odoo.exceptions import UserError
 from odoo.tools import format_date
@@ -243,3 +244,26 @@ class TestAccountMoveInalterableHash(AccountTestInvoicingCommon):
         Model.write(moves[1], {'date': fields.Date.from_string('2023-01-07')})
         integrity_check = moves.company_id._check_hash_integrity()['results'][0]
         self.assertEqual(integrity_check['msg_cover'], f'Corrupted data on journal entry with id {moves[1].id}.')
+
+    def test_account_move_hash_with_cash_rounding(self):
+        # Enable inalterable hash
+        self.company_data['default_journal_sale'].restrict_mode_hash_table = True
+        # Required for `invoice_cash_rounding_id` to be visible in the view
+        self.env.user.groups_id += self.env.ref('account.group_cash_rounding')
+        # Test 'add_invoice_line' rounding
+        invoice = self.init_invoice('out_invoice', products=self.product_a+self.product_b)
+        move_form = Form(invoice)
+        # Add a cash rounding having 'add_invoice_line'.
+        move_form.invoice_cash_rounding_id = self.cash_rounding_a
+        with move_form.invoice_line_ids.edit(0) as line_form:
+            line_form.price_unit = 999.99
+        move_form.save()
+
+        # Should not raise
+        invoice.action_post()
+
+        self.assertEqual(invoice.amount_total, 1410.0)
+        self.assertEqual(invoice.amount_untaxed, 1200.0)
+        self.assertEqual(invoice.amount_tax, 210)
+        self.assertEqual(len(invoice.invoice_line_ids), 2)
+        self.assertEqual(len(invoice.line_ids), 6)