[FIX] sale_stock,stock_account: ignore SVL without any qty

In some conditions, confirming an invoice will raise an Odoo Server
Error due to a division by zero.

To reproduce the issue:
(Need sale_management)
1. Create a product category PC:
    - Costing Method: Average Cost (AVCO)
    - Inventory Valuation: Automated
2. Create a product P:
    - Product Type: Storable
    - Category: PC
    - Cost: 50
3. Create a sale order SO:
    - 5 x P
4. Confirm and process the delivery D
5. Edit P:
    - Cost: 40
6. Open D and create a return R:
    - 1 x P without "Update quantities on SO/PO"
7. Process R
8. In Inventory, create a transfer T:
    - Operation Type: Receipt
    - 1 x P
9. Process T
10. Back to SO, create an invoice and post it

Error: an Odoo Server Error is raised: "ZeroDivisionError: float
division by zero"

When validating the transfer T, a stock valuation layer is created with
a zero quantity and is linked to the first SO.order_line.move_ids (i.e.,
the SM from Stock to Customer with 5 x P)
https://github.com/odoo/odoo/blob/dfab388fdf8c7597774ff1738a1b09295c12fb49/addons/stock_account/models/product.py#L439-L450

Then, when posting the invoice, this SVL is used to make a division:
https://github.com/odoo/odoo/blob/dfab388fdf8c7597774ff1738a1b09295c12fb49/addons/stock_account/models/product.py#L690-L691

In such cases, we should ignore this SVL and use the standard price:
https://github.com/odoo/odoo/blob/dfab388fdf8c7597774ff1738a1b09295c12fb49/addons/stock_account/models/product.py#L695-L699

OPW-2647921
OPW-2646419

closes odoo/odoo#77909

X-original-commit: d5eccda583e28a15e8a74a4e82f9e76ec32d0806
Signed-off-by: William Henrotin <Whenrow@users.noreply.github.com>

addons/sale_stock/tests/test_anglo_saxon_valuation.py

@@ -478,6 +478,67 @@ class TestAngloSaxonValuation(ValuationReconciliationTestCommon):
         self.assertEqual(income_aml.debit, 0)
         self.assertEqual(income_aml.credit, 24)
 
+    def test_avco_ordered_return_and_receipt(self):
+        """ Sell and deliver some products before the user encodes the products receipt """
+        product = self.product
+        product.invoice_policy = 'order'
+        product.type = 'product'
+        product.categ_id.property_cost_method = 'average'
+        product.categ_id.property_valuation = 'real_time'
+        product.list_price = 100
+        product.standard_price = 50
+
+        so = self.env['sale.order'].create({
+            'partner_id': self.partner_a.id,
+            'partner_invoice_id': self.partner_a.id,
+            'partner_shipping_id': self.partner_a.id,
+            'order_line': [(0, 0, {
+                'name': product.name,
+                'product_id': product.id,
+                'product_uom_qty': 5.0,
+                'product_uom': product.uom_id.id,
+                'price_unit': product.list_price})],
+        })
+        so.action_confirm()
+
+        pick = so.picking_ids
+        pick.move_lines.write({'quantity_done': 5})
+        pick.button_validate()
+
+        product.standard_price = 40
+
+        stock_return_picking_form = Form(self.env['stock.return.picking']
+            .with_context(active_ids=pick.ids, active_id=pick.sorted().ids[0], active_model='stock.picking'))
+        return_wiz = stock_return_picking_form.save()
+        return_wiz.product_return_moves.quantity = 1
+        return_wiz.product_return_moves.to_refund = False
+        res = return_wiz.create_returns()
+
+        return_pick = self.env['stock.picking'].browse(res['res_id'])
+        return_pick.move_lines.write({'quantity_done': 1})
+        return_pick.button_validate()
+
+        picking = self.env['stock.picking'].create({
+            'location_id': self.env.ref('stock.stock_location_suppliers').id,
+            'location_dest_id': self.company_data['default_warehouse'].lot_stock_id.id,
+            'picking_type_id': self.company_data['default_warehouse'].in_type_id.id,
+        })
+        # We don't set the price_unit so that the `standard_price` will be used (see _get_price_unit()):
+        self.env['stock.move'].create({
+            'name': 'test_immediate_validate_1',
+            'location_id': self.env.ref('stock.stock_location_suppliers').id,
+            'location_dest_id': self.company_data['default_warehouse'].lot_stock_id.id,
+            'picking_id': picking.id,
+            'product_id': product.id,
+            'product_uom': product.uom_id.id,
+            'quantity_done': 1,
+        })
+        picking.button_validate()
+
+        invoice = so._create_invoices()
+        invoice.action_post()
+        self.assertEqual(invoice.state, 'posted')
+
     # -------------------------------------------------------------------------
     # AVCO Delivered
     # -------------------------------------------------------------------------

addons/stock_account/models/product.py

@@ -673,6 +673,8 @@ class ProductProduct(models.Model):
         qty_to_take_on_candidates = qty_to_invoice
         tmp_value = 0  # to accumulate the value taken on the candidates
         for candidate in candidates:
+            if not candidate.quantity:
+                continue
             candidate_quantity = abs(candidate.quantity)
             if candidate.stock_move_id.id in returned_quantities:
                 candidate_quantity -= returned_quantities[candidate.stock_move_id.id]