Failure to merge mappings of field named properties

[eyalkoren]

Elasticsearch Version

8.14.0

Installed Plugins

No response

Java Version

bundled

OS Version

Darwin

Problem Description

The new merge algorithm of raw field mappings that was merged through #97317 introduced a new failure when merging mappings of fields named properties. See details in the comment posted to the related PR.

Steps to Reproduce

Merging:

  "template": {
    "mappings": {
      "properties": {
        "properties": {
          "properties": {
            "child1": {
              "type": "text"
            }
          }
        }
      }
    }
  }

with:

  "template": {
    "mappings": {
      "properties": {
        "properties": {
          "properties": {
            "child2": {
              "type": "long"
            }
          }
        }
      }
    }
  }

should yield:

  "template": {
    "mappings": {
      "properties": {
        "properties": {
          "properties": {
            "child1": {
              "type": "text"
            },
            "child2": {
              "type": "long"
            }
          }
        }
      }
    }
  }

but instead yields:

  "template": {
    "mappings": {
      "properties": {
        "properties": {
          "properties": {
            "child2": {
              "type": "long"
            }
          }
        }
      }
    }
  }

Logs (if relevant)

No response

[elasticsearchmachine]

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

[eyalkoren]

@chiarch84 the fix has been merged and backported.
Once 8.14.1 is released, please try again and let us know if the issue has been resolved.

[chiarch84]

Super! Thanks for your help! I'll let you know!