What is the bug?
Sorting on nested fields does not sort inner_hits of response.

Dataset:

{"index":{"_id":"1"}}
{"message":[{"info":"c"},{"info":"a"}]}
{"index":{"_id":"2"}}
{"message":{"info":"d"}}

Mapping:

{
  "mappings": {
    "properties": {
      "message": {
        "type": "nested",
        "properties": {
          "info": {
            "type": "keyword",
            "index": "true"
          }
        }
      }
    }
  }
}

Query:

SELECT nested(message.info) FROM nested_objects ORDER BY nested(message.info) DESC;

Response:

{
    "schema": [
        {
            "name": "message.info",
            "type": "keyword"
        }
    ],
    "total": 3,
    "datarows": [
        [
            "d"
        ],
        [
            "c"
        ],
        [
            "a"
        ]
    ],
    "size": 3,
    "status": 200
}

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Upload dataset with index mapping.
2. Run SQL query.
3. Verify Results.

What is the expected behavior?
The hits portion of the response is sorted, and the inner_hits portion is not sorted. The inner_hits could be sorted, but this would be two separate sorts and all returned data would not be one contiguous sort. Perhaps an in-memory solution may be the only fix here.

What is your host/environment?

• OS: IOS
• Version: 13.4.1
• Plugins: SQL

Do you have any screenshots?
N/A

Do you have any additional context?
Legacy engine bug.