From 772a2ba023b16f7f24ebbd57d57c1e55bbcd47e0 Mon Sep 17 00:00:00 2001
From: "Andrea Grazioso (agr-odoo)" <agr@odoo.com>
Date: Thu, 12 Jan 2023 13:18:24 +0000
Subject: [PATCH] [FIX] account: payment term discount affecting fixed tax

In Settings>Accounting set 'Cash Discount Tax Reduction' to 'Always'
Have a payment term 'D' with discount
Have a fixed tax 'F'
Create an invoice with paymen term 'D', and 'F' on a line

Issue: Tax amount will be affected by the discount, this should not
occur for fixed taxes

opw-3119894

X-original-commit: e18292d0079ab83673e3b5b406ebee9b5929f06d
Part-of: odoo/odoo#110078
---
 addons/account/models/account_move_line.py    |  3 +-
 .../tests/test_early_payment_discount.py      | 36 +++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/addons/account/models/account_move_line.py b/addons/account/models/account_move_line.py
index 8f5c5a80d00..7e51a0b3783 100644
--- a/addons/account/models/account_move_line.py
+++ b/addons/account/models/account_move_line.py
@@ -1006,12 +1006,13 @@ class AccountMoveLine(models.Model):
             for percentages in percentages_to_apply:
                 percentage = percentages['discount_percentage'] / 100
                 line_percentage = percentages['term_percentage']
+                taxes = line.tax_ids.filtered(lambda t: t.amount_type != 'fixed')
                 epd_needed_vals = epd_needed.setdefault(
                     frozendict({
                         'move_id': line.move_id.id,
                         'account_id': line.account_id.id,
                         'analytic_distribution': line.analytic_distribution,
-                        'tax_ids': [Command.set(line.tax_ids.ids)],
+                        'tax_ids': [Command.set(taxes.ids)],
                         'tax_tag_ids': [Command.set(line.tax_tag_ids.ids)],
                         'display_type': 'epd',
                     }),
diff --git a/addons/account/tests/test_early_payment_discount.py b/addons/account/tests/test_early_payment_discount.py
index 7d44856fea9..27cc2a16213 100644
--- a/addons/account/tests/test_early_payment_discount.py
+++ b/addons/account/tests/test_early_payment_discount.py
@@ -60,6 +60,42 @@ class TestAccountEarlyPaymentDiscount(AccountTestInvoicingCommon):
                     fields.Date.from_string('2019-01-11') or False
                 )
 
+    # ========================== Tests Taxes Amounts =============================
+    def test_fixed_tax_amount_discounted_payment_mixed(self):
+        self.env.company.early_pay_discount_computation = 'mixed'
+        fixed_tax = self.env['account.tax'].create({
+            'name': 'Test 0.05',
+            'amount_type': 'fixed',
+            'amount': 0.05,
+        })
+
+        invoice = self.env['account.move'].create({
+            'move_type': 'out_invoice',
+            'partner_id': self.partner_a.id,
+            'invoice_date': '2019-01-01',
+            'date': '2019-01-01',
+            'invoice_line_ids': [Command.create({
+                'name': 'line',
+                'price_unit': 1000.0,
+                'tax_ids': [Command.set(self.product_a.taxes_id.ids + fixed_tax.ids)],
+            })],
+            'invoice_payment_term_id': self.early_pay_mixed_5_10.id,
+        })
+        self.assertInvoiceValues(invoice, [
+            # pylint: disable=bad-whitespace
+            {'display_type': 'epd',             'balance': -75.0},
+            {'display_type': 'epd',             'balance': 75.0},
+            {'display_type': 'product',         'balance': -1000.0},
+            {'display_type': 'tax',             'balance': -138.75},
+            {'display_type': 'tax',             'balance': -0.05},
+            {'display_type': 'payment_term',    'balance': 569.4},
+            {'display_type': 'payment_term',    'balance': 569.4},
+        ], {
+            'amount_untaxed': 1000.0,
+            'amount_tax': 138.8,
+            'amount_total': 1138.8,
+        })
+
     # ========================== Tests Payment Register ==========================
     def test_register_discounted_payment_on_single_invoice(self):
         self.company_data['company'].early_pay_discount_computation = 'included'