Restore shipment method in sale when removing load orders.

This commit refs #26394

load.py

@@ -536,6 +536,16 @@ class LoadOrder(metaclass=PoolMeta):
                     order=record.rec_name))
         super(LoadOrder, cls).draft(records)
 
+    @classmethod
+    def delete(cls, records):
+        Sale = Pool().get('sale.sale')
+
+        sales = [r.sale for r in records if r.sale
+            and not r.sale.is_origin_load]
+        super().delete(records)
+        if sales:
+            Sale.restore_load_shipment_method(sales)
+
     def _get_inventory_move(self, move):
         pool = Pool()
         Move = pool.get('stock.move')

sale.py

@@ -76,19 +76,24 @@ class Sale(metaclass=PoolMeta):
         res.extend(super(Sale, cls).copy(clear_methods, default=default))
         return res
 
+    @property
+    def is_origin_load(self):
+        LoadOrder = Pool().get('carrier.load.order')
+        return bool(self.origin
+            and isinstance(self.origin, LoadOrder))
+
     @classmethod
     def cancel(cls, records):
         for record in records:
             if (record.loads and record.origin
-                    and record.origin.__name__ != 'carrier.load.order'):
+                    and not record.is_origin_load):
                 raise UserError(gettext(
                     'carrier_load_ul.msg_sale_sale_cancel_loads',
                     sale=record.rec_name))
-        super(Sale, cls).cancel(records)
+        super().cancel(records)
 
     def check_method(self):
-        if not self.loads and (not self.origin
-                or self.origin.__name__ != 'carrier.load.order'):
+        if not self.loads and not self.is_origin_load:
             super(Sale, self).check_method()
             return
         if (self.shipment_method == 'invoice'
@@ -101,12 +106,19 @@ class Sale(metaclass=PoolMeta):
 
     @classmethod
     def quote(cls, records):
+        cls.restore_load_shipment_method(records)
+        super().quote(records)
+
+    @classmethod
+    def restore_load_shipment_method(cls, records):
+        to_update = []
         for record in records:
             if ((record.shipment_method, record.invoice_method) == (
                     'manual', 'shipment') and not record.loads):
                 record.shipment_method = 'order'
-                record.save()
-        super(Sale, cls).quote(records)
+                to_update.append(record)
+        if to_update:
+            cls.save(to_update)
 
     @classmethod
     def process(cls, sales):