[FIX] purchase_stock: update RR's qty_to_order on POL's qty change

When a RR updates the qty of a POL, the qty to order of that RR will
be incorrect

To reproduce the issue:
1. Create a product
   - Storable
   - With a vendor
2. Create a RR:
   - Min 0
   - Max 0
   - Factor 1
3. Confirm a delivery with 1 x P
   - It should create a PO
4. Confirm a second delivery with 1 x P
    - The POL of the PO should be updated
5. Open the Replenishment page

Error: The qty to order of the product is 1 while it should be 0

`qty_to_order` is a computed field and one of the `depends` is the POL
related to the product. This explains why, after step 3, everything
is ok: the compute is triggered (because of the new POL) and the qty
to order becomes 0. However, step 4, the POL qty is updated -> it
does not concern any `depends` -> the compute is not triggered,
hence the error

OPW-3292297

closes odoo/odoo#128279

X-original-commit: 80521431601323c1eb7c85cafbf08e8ae0adbdd6
Signed-off-by: William Henrotin (whe) <whe@odoo.com>
Signed-off-by: Adrien Widart (awt) <awt@odoo.com>

addons/purchase_stock/models/stock.py

@@ -97,7 +97,7 @@ class Orderpoint(models.Model):
     vendor_id = fields.Many2one(related='supplier_id.partner_id', string="Vendor", store=True)
     purchase_visibility_days = fields.Float(default=0.0, help="Visibility Days applied on the purchase routes.")
 
-    @api.depends('product_id.purchase_order_line_ids', 'product_id.purchase_order_line_ids.state')
+    @api.depends('product_id.purchase_order_line_ids.product_qty', 'product_id.purchase_order_line_ids.state')
     def _compute_qty(self):
         """ Extend to add more depends values """
         return super()._compute_qty()

addons/purchase_stock/tests/test_reordering_rule.py

@@ -259,6 +259,64 @@ class TestReorderingRule(TransactionCase):
         self.assertEqual(len(purchase_order.order_line), 1, 'Not enough purchase order lines created.')
         purchase_order.button_confirm()
 
+    def test_reordering_rule_triggered_two_times(self):
+        """
+        A product P wth RR 0-0-1.
+        Confirm a delivery with 1 x P -> PO created for it.
+        Confirm a second delivery, with 1 x P again:
+        - The PO should be updated
+        - The qty to order of the RR should be zero
+        """
+        warehouse = self.env['stock.warehouse'].search([('company_id', '=', self.env.user.id)], limit=1)
+        stock_location = warehouse.lot_stock_id
+        out_type = warehouse.out_type_id
+        customer_location = self.env.ref('stock.stock_location_customers')
+
+        rr = self.env['stock.warehouse.orderpoint'].create({
+            'location_id': stock_location.id,
+            'product_id': self.product_01.id,
+            'product_min_qty': 0,
+            'product_max_qty': 0,
+            'qty_multiple': 1,
+        })
+
+        delivery = self.env['stock.picking'].create({
+            'picking_type_id': out_type.id,
+            'location_id': stock_location.id,
+            'location_dest_id': customer_location.id,
+            'move_ids': [(0, 0, {
+                'name': self.product_01.name,
+                'product_id': self.product_01.id,
+                'product_uom_qty': 1,
+                'product_uom': self.product_01.uom_id.id,
+                'location_id': stock_location.id,
+                'location_dest_id': customer_location.id,
+            })]
+        })
+        delivery.action_confirm()
+
+        pol = self.env['purchase.order.line'].search([('product_id', '=', self.product_01.id)])
+        self.assertEqual(pol.product_qty, 1.0)
+        self.assertEqual(rr.qty_to_order, 0.0)
+
+        delivery = self.env['stock.picking'].create({
+            'picking_type_id': out_type.id,
+            'location_id': stock_location.id,
+            'location_dest_id': customer_location.id,
+            'move_ids': [(0, 0, {
+                'name': self.product_01.name,
+                'product_id': self.product_01.id,
+                'product_uom_qty': 1,
+                'product_uom': self.product_01.uom_id.id,
+                'location_id': stock_location.id,
+                'location_dest_id': customer_location.id,
+            })]
+        })
+        delivery.action_confirm()
+
+        self.assertEqual(pol.product_qty, 2.0)
+        self.assertEqual(rr.qty_to_order, 0.0)
+
     def test_replenish_report_1(self):
         """Tests the auto generation of manual orderpoints.