[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>

2 files changed, 44 insertions, 8 deletions

diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index 9ff2307c4f5..d2ea1e2fb9d 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -619,19 +619,22 @@ class AccountMove(models.Model):
                     'tax_base_amount': 0.0,
                     'grouping_dict': False,
                 }
-        self.line_ids -= to_remove
+        if not recompute_tax_base_amount:
+            self.line_ids -= to_remove
 
         # ==== Mount base lines ====
         for line in self.line_ids.filtered(lambda line: not line.tax_repartition_line_id):
             # Don't call compute_all if there is no tax.
             if not line.tax_ids:
-                line.tax_tag_ids = [(5, 0, 0)]
+                if not recompute_tax_base_amount:
+                    line.tax_tag_ids = [(5, 0, 0)]
                 continue
 
             compute_all_vals = _compute_base_line_taxes(line)
 
             # Assign tags on base line
-            line.tax_tag_ids = compute_all_vals['base_tags'] or [(5, 0, 0)]
+            if not recompute_tax_base_amount:
+                line.tax_tag_ids = compute_all_vals['base_tags'] or [(5, 0, 0)]
 
             tax_exigible = True
             for tax_vals in compute_all_vals['taxes']:
@@ -653,20 +656,22 @@ class AccountMove(models.Model):
                 taxes_map_entry['amount'] += tax_vals['amount']
                 taxes_map_entry['tax_base_amount'] += self._get_base_amount_to_display(tax_vals['base'], tax_repartition_line, tax_vals['group'])
                 taxes_map_entry['grouping_dict'] = grouping_dict
-            line.tax_exigible = tax_exigible
+            if not recompute_tax_base_amount:
+                line.tax_exigible = tax_exigible
 
         # ==== Process taxes_map ====
         for taxes_map_entry in taxes_map.values():
             # The tax line is no longer used in any base lines, drop it.
             if taxes_map_entry['tax_line'] and not taxes_map_entry['grouping_dict']:
-                self.line_ids -= taxes_map_entry['tax_line']
+                if not recompute_tax_base_amount:
+                    self.line_ids -= taxes_map_entry['tax_line']
                 continue
 
             currency = self.env['res.currency'].browse(taxes_map_entry['grouping_dict']['currency_id'])
 
             # Don't create tax lines with zero balance.
             if currency.is_zero(taxes_map_entry['amount']):
-                if taxes_map_entry['tax_line']:
+                if taxes_map_entry['tax_line'] and not recompute_tax_base_amount:
                     self.line_ids -= taxes_map_entry['tax_line']
                 continue
 
@@ -674,8 +679,9 @@ class AccountMove(models.Model):
             tax_base_amount = currency._convert(taxes_map_entry['tax_base_amount'], self.company_currency_id, self.company_id, self.date or fields.Date.context_today(self))
 
             # Recompute only the tax_base_amount.
-            if taxes_map_entry['tax_line'] and recompute_tax_base_amount:
-                taxes_map_entry['tax_line'].tax_base_amount = tax_base_amount
+            if recompute_tax_base_amount:
+                if taxes_map_entry['tax_line']:
+                    taxes_map_entry['tax_line'].tax_base_amount = tax_base_amount
                 continue
 
             balance = currency._convert(
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()