Lot invoicing + Fee padding

modules/purchase_trade/lot.py

@@ -5049,6 +5049,8 @@ class LotInvoiceStart(ModelView):
         return getattr(record, 'id', None) or id(record)
 
     def _fee_wizard_padding_quantity(self, fee, padding_by_lot):
+        if self._fee_wizard_ignores_padding(fee):
+            return Decimal(0)
         if not getattr(fee, 'add_padding', False):
             return Decimal(0)
         quantity = Decimal(0)
@@ -5090,7 +5092,12 @@ class LotInvoiceStart(ModelView):
                 return Decimal(str(getattr(lot.line, 'unit_price', 0) or 0))
         return Decimal(0)
 
-    @fields.depends('type', 'sale_padding', 'lot_s', 'fee_sale')
+    def _fee_wizard_ignores_padding(self, fee):
+        return (
+            self.action == 'final'
+            and getattr(fee, 'state', None) == 'invoiced')
+
+    @fields.depends('type', 'action', 'sale_padding', 'lot_s', 'fee_sale')
     def on_change_sale_padding(self):
         if self.type != 'sale' or not self.fee_sale:
             return

modules/purchase_trade/tests/test_module.py

@@ -3369,6 +3369,39 @@ class PurchaseTradeTestCase(ModuleTestCase):
         self.assertEqual(fee_line.fee_quantity, Decimal('7'))
         self.assertEqual(fee_line.fee_amount, Decimal('14.00'))
 
+    def test_lot_invoice_final_existing_fee_display_ignores_padding(self):
+        'final DN/CN fee display ignores padding for the current value'
+        start = lot_module.LotInvoiceStart()
+        unit = SimpleNamespace(id=1)
+        sale_line = SimpleNamespace(unit=unit, unit_price=Decimal('100'))
+        lot = SimpleNamespace(id=10, sale_line=sale_line)
+        fee = SimpleNamespace(
+            add_padding=True,
+            state='invoiced',
+            mode='pprice',
+            price=Decimal('2'),
+            quantity=Decimal('5'),
+            sale_line=sale_line,
+            _get_effective_fee_lots=Mock(return_value=[lot]),
+            _get_effective_fee_lots_quantity=Mock(return_value=Decimal('5')),
+            _convert_padding_quantity=Mock(
+                side_effect=lambda quantity, unit: Decimal(str(quantity))),
+            get_quantity=Mock(return_value=Decimal('5')))
+        fee_line = SimpleNamespace(
+            fee=fee,
+            fee_quantity=Decimal('5'),
+            fee_amount=Decimal('10'))
+        start.type = 'sale'
+        start.action = 'final'
+        start.sale_padding = Decimal('2')
+        start.lot_s = [SimpleNamespace(lot=lot)]
+        start.fee_sale = [fee_line]
+
+        start.on_change_sale_padding()
+
+        self.assertEqual(fee_line.fee_quantity, Decimal('5'))
+        self.assertEqual(fee_line.fee_amount, Decimal('10.00'))
+
     def test_fee_get_non_cog_returns_zero_without_move_lines(self):
         'fee non-cog amount is zero before any accounting move line exists'
         fee = fee_module.Fee()