Fixed bug on sale creation from order load when sale_discount is present

This commit refs #25427

__init__.py

@@ -54,6 +54,10 @@ def register():
         load.Load4,
         module='carrier_load', type_='model',
         depends=['carrier_vehicle'])
+    Pool.register(
+        load.LoadOrder4,
+        module='carrier_load', type_='model',
+        depends=['sale_discount'])
     Pool.register(
         load.LoadSheet,
         cmr.CMR,

load.py

@@ -2078,3 +2078,13 @@ class Load4(metaclass=PoolMeta):
             self.driver_identifier = self.vehicle.driver_identifier
             self.trailer_number = self.vehicle.trailer_number
             self.vehicle_number = self.vehicle.number
+
+
+class LoadOrder4(metaclass=PoolMeta):
+    __name__ = 'carrier.load.order'
+
+    def _get_load_sale_line(self, sale, key, grouped_items):
+        line = super()._get_load_sale_line(sale, key, grouped_items)
+        line.base_price = line.unit_price
+        line.discount = 0
+        return line

tryton.cfg

@@ -18,6 +18,7 @@ extras_depend:
     sale_cost_apply_invoice
     analytic_sale
     carrier_vehicle
+    sale_discount
 
 xml:
   load.xml