Magento removes `save_rewrites_history` from custom attribute list from REST API call

Question

I was trying to update a product with new url-key. But create permanent redirect to the old url doesnt work from API.

First i am creating product with this JSON data http://domain.com/rest/all/V1/products

$post ='{
        "product": {
        "sku": "B501-SKU",
        "name": "B501",
        "price": 30.00,
        "status": 1,
        "type_id": "simple",
        "attribute_set_id":4,
        "weight": 1
      }
    }';

Now if i want to update the url and create a 301 redirect from old url to new url then i am hitting this http://domain.com/rest/all/V1/products/B501-SKU (sku of the product)

    $post ='{
  "product": {
   "name": "B506",
   "customAttributes": [
        {
        "attribute_code":"meta_title",
        "value":"test"
        },
        {
        "attribute_code":"save_rewrites_history",
        "value":1
        },
        {
        "attribute_code": "url_key",
        "value": "b506"
        }
    ]
 }
}';

Now if i go to Magento\Catalog\Model\ProductRepository save() function and try to print the product object i will see that it has removed save_rewrites_history and has kept rest as is. probably because its not attribute.

A solution to the problem

1) created a new attribute and if you set the attribute value then

if($product->getData('new_attribute') == 1 && $this->areaCode->getAreaCode() == 'webapi_rest') {
        $product->setData('save_rewrites_history',1);
    }

It fixed the problem but can anyone tell me how magento refines the data before the save function? Why only attributes are getting passed.

Answer 1

As still now i didnt found a solution here is what i am doing right now to achieve it.

1) created a new attribute with 1 or 0 value. Now go to Magento\Catalog\Model\ProductRepository save function. And added the below piece of code in the beginning.(I would advice to override it and add the code as i did this only for development purposes.)

if($product->getData('new_attribute') == 1 && $this->areaCode->getAreaCode() == 'webapi_rest') {
        $product->setData('save_rewrites_history',1);
    }

Now if you send an updated url then it will create a 301 redirect from the new url to the old one.