[FIX] mrp_multi_level: when a product is a kit do not check rule

When you procure a kit, it doesn't matter what the route configuration
is on the product itself but on its children, so it is not needed to
check anything else but the BoM to assign the 'phantom' supply
method.

Also do not assign a BoM when the supply method is not phantom or manufacture.

mrp_multi_level/models/product_mrp_area.py

@@ -206,18 +206,19 @@ class ProductMRPArea(models.Model):
         boms_by_product = self.env["mrp.bom"]._bom_find(self.mapped("product_id"))
         for rec in self:
             rule = rec._get_rule()
-            if not rule:
+            bom = boms_by_product.get(rec.product_id, self.env["mrp.bom"])
+            if bom.type == "phantom":
+                rec.supply_method = "phantom"
+                rec.supply_bom_id = bom
+            elif not rule:
                 rec.supply_method = "none"
                 rec.supply_bom_id = False
-                continue
-            # Determine the supply method based on the final rule.
-            bom = boms_by_product.get(rec.product_id, self.env["mrp.bom"])
-            rec.supply_method = (
-                "phantom"
-                if rule.action == "manufacture" and bom.type == "phantom"
-                else rule.action
-            )
-            rec.supply_bom_id = bom
+            elif rule.action == "manufacture":
+                rec.supply_method = rule.action
+                rec.supply_bom_id = bom
+            else:
+                rec.supply_method = rule.action
+                rec.supply_bom_id = False
 
     @api.depends(
         "mrp_area_id", "supply_method", "product_id.route_ids", "product_id.seller_ids"

mrp_multi_level/tests/test_mrp_multi_level.py

@@ -449,6 +449,16 @@ class TestMrpMultiLevel(TestMrpMultiLevelCommon):
         ]
         product_mrp_area._compute_supply_method()
         self.assertEqual(product_mrp_area.supply_method, "buy")
+        kit_bom = self.mrp_bom_obj.create(
+            {
+                "product_tmpl_id": self.fp_4.product_tmpl_id.id,
+                "product_id": self.fp_4.id,
+                "type": "phantom",
+            }
+        )
+        product_mrp_area._compute_supply_method()
+        self.assertEqual(product_mrp_area.supply_method, "phantom")
+        self.assertEqual(product_mrp_area.supply_bom_id, kit_bom)
 
     def test_18_priorize_safety_stock(self):
         now = datetime.now()