Cannot get semantic_text field mapping with defaults when inference service does not exist #145136

Elasticsearch Version

9.3, 9.2

Installed Plugins

No response

Java Version

bundled

OS Version

N/A

Problem Description

If a user creates a semantic_text field that references an inference service that doesn't exist, they cannot use the get field mapping API with include_defaults to get the mapping.

Steps to Reproduce

1. Create an index with a semantic_text field that references a nonexistent inference service

PUT test-index
{
  "mappings": {
    "properties": {
      "semantic_field": {
        "type": "semantic_text",
        "inference_id": "missing_inference_id"
      }
    }
  }
}

2. Try to use the get field mapping API with include_defaults to get the mapping

GET /test-index/_mapping/field/semantic_field?include_defaults

The response is empty JSON:

{}

The request fails silently, with no errors returned to the user and no errors logged.

Logs (if relevant)

No response