[FIX] purchase: always display inactive taxes on purchase order

Steps to reproduce:

- Create a PO with a tax
- Confirm PO and bill it
- Deactivate tax

Issue:
Tax is shown on bill but not on PO

Solution:
Make sure that we display tax even if inactive.

opw-3631087

closes odoo/odoo#148778

X-original-commit: 4e424750eccff168c3cbb1a3f8411b35905717f3
Signed-off-by: Adrien Widart (awt) <awt@odoo.com>
Signed-off-by: Mattis Megevand (mmeg) <mmeg@odoo.com>

addons/purchase/models/purchase_order_line.py

@@ -30,7 +30,7 @@ class PurchaseOrderLine(models.Model):
         compute='_compute_price_unit_and_date_planned_and_name',
         digits='Discount',
         store=True, readonly=False)
-    taxes_id = fields.Many2many('account.tax', string='Taxes', domain=['|', ('active', '=', False), ('active', '=', True)])
+    taxes_id = fields.Many2many('account.tax', string='Taxes', domain=['|', ('active', '=', False), ('active', '=', True)], context={'active_test': False})
     product_uom = fields.Many2one('uom.uom', string='Unit of Measure', domain="[('category_id', '=', product_uom_category_id)]")
     product_uom_category_id = fields.Many2one(related='product_id.uom_id.category_id')
     product_id = fields.Many2one('product.product', string='Product', domain=[('purchase_ok', '=', True)], change_default=True, index='btree_not_null')

addons/purchase/tests/test_purchase_tax_totals.py

@@ -60,3 +60,26 @@ class PurchaseTestTaxTotals(TestTaxTotals):
         })
         tax_purchase.invalidate_model(fnames=['is_used'])
         self.assertTrue(tax_purchase.is_used)
+
+    def test_archived_tax_totals(self):
+        tax_10 = self.env['account.tax'].create({
+            'name': "tax_10",
+            'amount_type': 'percent',
+            'amount': 10.0,
+            'tax_group_id': self.tax_group1.id,
+        })
+
+        po = self._create_document_for_tax_totals_test([
+            (100.0, tax_10),
+        ])
+        po.button_confirm()
+        po.order_line.qty_received = 1
+        po.action_create_invoice()
+
+        invoice = po.invoice_ids
+        invoice.invoice_date = '2020-01-01'
+        invoice.action_post()
+
+        old_ammount = po.amount_total
+        tax_10.active = False
+        self.assertEqual(po.amount_total, old_ammount)