minor fix

sale.py

@@ -42,19 +42,20 @@ class Sale(metaclass=PoolMeta):
             field_status_order = 'status_order' in Line._fields
             records = cls.browse([args['id']])
             lines_action = args.get('lines')
-            for action, lines in lines_action:
-                # action, lines = lines_tuple
-                if action == 'create' and len(lines) > 0:
-                    for line in lines:
-                        product = Product(line['product'])
-                        cls._add_values(product.template, line, field_status_order)
-            cls.write(records, args)
-            res = {
-                'record': {'id': args['id']},
-                'msg': 'Pedido Actualizado!!!',
-                'type': 'success',
-            }
-            return res
+            if lines_action:
+                for action, lines in lines_action:
+                    # action, lines = lines_tuple
+                    if action == 'create' and len(lines) > 0:
+                        for line in lines:
+                            product = Product(line['product'])
+                            cls._add_values(product.template, line, field_status_order)
+                cls.write(records, args)
+                res = {
+                    'record': {'id': args['id']},
+                    'msg': 'Pedido Actualizado!!!',
+                    'type': 'success',
+                }
+                return res
 
     @classmethod
     def _add_values(cls, template, line, field_status_order):
@@ -182,7 +183,8 @@ class Sale(metaclass=PoolMeta):
         if hasattr(sale, 'order_status'):
             cls.write([sale], {'order_status': 'requested'})
 
-        cls.write([sale], {'state': 'quotation'})
+        # this option is not possible because order can receive new products
+        # cls.write([sale], {'state': 'quotation'})
         cls.set_number([sale])
         sale.save()
         record = args.copy()