[FW][FIX] sale_stock_margin: make purchase_price overwrite consistent

addons/sale_margin/models/sale_order_line.py

@@ -38,5 +38,11 @@ def _compute_purchase_price(self):
     @api.depends('price_subtotal', 'product_uom_qty', 'purchase_price')
     def _compute_margin(self):
         for line in self:
-            line.margin = line.price_subtotal - (line.purchase_price * line.product_uom_qty)
-            line.margin_percent = line.price_subtotal and line.margin/line.price_subtotal
+            # Find alternative calculation when line is added to order from delivery
+            if line.qty_delivered and not line.product_uom_qty:
+                calculated_subtotal = line.price_unit * line.qty_delivered
+                line.margin = calculated_subtotal - (line.purchase_price * line.qty_delivered)
+                line.margin_percent = calculated_subtotal and line.margin / calculated_subtotal
+            else:
+                line.margin = line.price_subtotal - (line.purchase_price * line.product_uom_qty)
+                line.margin_percent = line.price_subtotal and line.margin / line.price_subtotal

addons/sale_stock_margin/models/sale_order_line.py

@@ -9,18 +9,22 @@ class SaleOrderLine(models.Model):
 
     @api.depends('move_ids', 'move_ids.stock_valuation_layer_ids', 'move_ids.picking_id.state')
     def _compute_purchase_price(self):
-        lines_without_moves = self.browse()
+        line_ids_to_pass = set()
         for line in self:
             product = line.product_id.with_company(line.company_id)
             if not line.has_valued_move_ids():
-                lines_without_moves |= line
-            elif product and product.cost_method != 'standard':
-                purch_price = product._compute_average_price(0, line.product_uom_qty, line.move_ids)
+                line_ids_to_pass.add(line.id)
+            elif (
+                # don't overwrite any existing value unless non-standard cost method
+                (line.product_id and line.product_id.categ_id and line.product_id.categ_id.property_cost_method != 'standard') or
+                # if line added from delivery, allow recomputation
+                (not line.product_uom_qty and line.qty_delivered)
+            ):
+                purch_price = product._compute_average_price(0, line.product_uom_qty or line.qty_to_invoice, line.move_ids)
                 if line.product_uom_id and line.product_uom_id != product.uom_id:
                     purch_price = product.uom_id._compute_price(purch_price, line.product_uom_id)
-                to_cur = line.currency_id or line.order_id.currency_id
                 line.purchase_price = line._convert_to_sol_currency(
                     purch_price,
                     product.cost_currency_id,
                 )
-        return super(SaleOrderLine, lines_without_moves)._compute_purchase_price()
+        return super(SaleOrderLine, self.browse(line_ids_to_pass))._compute_purchase_price()

addons/sale_stock_margin/tests/test_sale_stock_margin.py

@@ -316,3 +316,37 @@ def test_purchase_price_changes(self):
 
         self.assertEqual(so.state, 'sent')
         self.assertEqual(so.order_line[0].purchase_price, 15)
+        so.action_confirm()
+        self.assertEqual(so.order_line[0].purchase_price, 15)
+
+    def test_add_product_on_delivery_price_unit_on_sale(self):
+        """ Adding a product directly on a sale order's delivery should result in the new SOL
+        having its `purchase_price` and `margin` + `margin_percent` fields correctly calculated.
+        """
+        products = [self._create_product() for _ in range(2)]
+        for product, cost, price in zip(products, [20, 10], [25, 20]):
+            product.categ_id.property_cost_method = 'standard'
+            product.write({
+                'standard_price': cost,
+                'list_price': price,
+                'invoice_policy': 'delivery',
+            })
+        sale_order = self._create_sale_order()
+        self._create_sale_order_line(sale_order, products[0], 10, products[0].list_price)
+        sale_order.action_confirm()
+        delivery = sale_order.picking_ids[0]
+        with Form(delivery) as delivery_form:
+            with delivery_form.move_ids_without_package.new() as move:
+                move.product_id = products[1]
+                move.product_uom_qty = 10
+        delivery.move_ids.quantity = 10
+        delivery.button_validate()
+        self.assertRecordValues(
+            sale_order.order_line.filtered(lambda sol: sol.product_id == products[1]),
+            [{
+                'price_unit': products[1].list_price,
+                'purchase_price': products[1].standard_price,
+                'margin': 100,
+                'margin_percent': 0.5,
+            }]
+        )