return 0, true, nil
	}

	var src *File
	switch v := r.(type) {
	case *File:
		src = v
	case fileWithoutWriteTo:
		src = v.File
	default:
		return 0, false, nil
	}

	if src.checkValid("ReadFrom") != nil {
		// Avoid returning the error as we report handled as false,
		// leave further error handling as the responsibility of the caller.
		return 0, false, nil
	}