think\Model::autoCompleteData PHP Method

    protected function autoCompleteData($auto = [])
    {
        foreach ($auto as $field => $value) {
            if (is_integer($field)) {
                $field = $value;
                $value = null;
            }
            if (!in_array($field, $this->change)) {
                $this->setAttr($field, !is_null($value) ? $value : (isset($this->data[$field]) ? $this->data[$field] : $value));
            }
        }
    }