_ignored is not populated for a "scaled_float" field defined as "ignore_malformed"

[cnliao]

Elasticsearch Version

8.5.3

Installed Plugins

No response

Java Version

bundled

OS Version

5.4.0-124-generic

Problem Description

The _ignored field is not populated correctly under the following condition:

• A scaled_float field is defined as "ignore_malformed": true;
• A document with a malformed value for that field is indexed.

Steps to Reproduce

PUT my-index-000001
{
  "settings": {
    "index.mapping.ignore_malformed": true 
  },
  "mappings": {
    "properties": {
      "a_float": {
        "type": "scaled_float",
        "scaling_factor": 100, 
        "ignore_malformed": true
      },
      "a_long": {
        "type": "long",
        "ignore_malformed": true
      }
    }
  }
}

POST my-index-000001/_doc/1?refresh
{
  "a_float": "hello",
  "a_long": "hello"
}

GET my-index-000001/_search
{}

// Response
{
  "took": 0,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1,
    "hits": [
      {
        "_index": "my-index-000001",
        "_id": "1",
        "_score": 1,
        "_ignored": [
          "a_long"
          // should include "a_float" here
        ],
        "_source": {
          "a_float": "hello",
          "a_long": "hello"
        }
      }
    ]
  }
}

Logs (if relevant)

No response

[elasticsearchmachine]

Pinging @elastic/es-search (Team:Search)

[devnamrits]

Hi @javanna Can I pick this up?

Also, please usher a little bit regarding this issue.

[cbuescher]

@cnliao I just tried your reproduction on 8.6.2 and got the expected result in the _ignore field::

"_ignored": [
          "a_float",
          "a_long"
        ],

Can you check again with 8.6, might be already fixed.

[cbuescher]

This was fixed with #90565 in 8.6, therefore I'm closing this issue.

[cnliao]

GET my-index-000001/_search
{}

Fix confirmed at 8.6.2. Thank you all!