Fixed #21784: Correctly decode stdin input for migration defaults

            print("Please enter the default value now, as valid Python")

            print("The datetime module is available, so you can do e.g. datetime.date.today()")

            while True:

                code = input(">>> ")

                code = input(">>> ").decode(sys.stdin.encoding)

                if not code:

                    print("Please enter some code, or 'exit' (with no quotes) to exit.")

                elif code == "exit":