Add warehouse to invoice line

This ensures that the cost price used for COGS lines come from the right
warehouse when it is computed per warehouse.

issue10568
review362161002

invoice.py

@@ -118,6 +118,16 @@ class InvoiceLine(metaclass=PoolMeta):
             category = self.origin.unit.category.id
         return category
 
+    def get_warehouse(self, name):
+        pool = Pool()
+        PurchaseLine = pool.get('purchase.line')
+        warehouse = super().get_warehouse(name)
+        if (not warehouse
+                and isinstance(self.origin, PurchaseLine)
+                and self.origin.purchase.warehouse):
+            warehouse = self.origin.purchase.warehouse.id
+        return warehouse
+
     @property
     def origin_name(self):
         pool = Pool()