[IMP] account: introduce a new field on move lines to avoid inverting tax tags

The sign of tax tags sometimes could get inverted explicitly. It typically happened for misc operations, so :
    - manual entries
    - CABA entries
    - writeoffs created from the reconciliation widget

We had to do things this way in stable to fix those use cases, but it's not ideal, as the tags shown to the user were inverted, so it was a bit confusing, as one would have expected to see the exact same tags as on tax configuration.

We fix that by using a boolean field on account.move.line telling whether or not the sign must be inverted. This allows keeping the same tags as in the tax config, and simplifies the computation of the tax report's multiplicator, making the overall model more intuitive for both user and developper.

Task 2363287

closes #62536

closes odoo/odoo#64558

Related: odoo/enterprise#15031
Related: odoo/upgrade#1983
Signed-off-by: Laurent Smet <smetl@users.noreply.github.com>
Signed-off-by: oco-odoo <oco-odoo@users.noreply.github.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/addons/hr_expense/tests/test_expenses.py b/addons/hr_expense/tests/test_expenses.py
index f2d1fd86676..9cf10b651bf 100644
--- a/addons/hr_expense/tests/test_expenses.py
+++ b/addons/hr_expense/tests/test_expenses.py
@@ -138,3 +138,33 @@ class TestExpenses(TestExpenseCommon):
                 'currency_id': self.company_data['currency'].id,
             },
         ])
+
+    def test_expenses_with_tax_and_lockdate(self):
+        ''' Test creating a journal entry for multiple expenses using taxes. A lock date is set in order to trigger
+        the recomputation of the taxes base amount.
+        '''
+        self.env.company.tax_lock_date = '2020-02-01'
+
+        expense = self.env['hr.expense.sheet'].create({
+            'name': 'Expense for John Smith',
+            'employee_id': self.expense_employee.id,
+            'accounting_date': '2020-01-01'
+        })
+
+        for i in range(2):
+            expense_line = self.env['hr.expense'].create({
+                'name': 'Car Travel Expenses',
+                'employee_id': self.expense_employee.id,
+                'product_id': self.product_a.id,
+                'unit_amount': 350.00,
+                'tax_ids': [(6, 0, [self.tax_purchase_a.id])],
+                'sheet_id': expense.id,
+                'analytic_account_id': self.analytic_account_1.id,
+            })
+            expense_line._onchange_product_id_date_account_id()
+
+        expense.action_submit_sheet()
+        expense.approve_expense_sheets()
+
+        # Assert not "Cannot create unbalanced journal entry" error.
+        expense.action_sheet_move_create()