fielddata_fields query string parameter ignored

[gmarz]

Specifying fielddata_fields on the query string seems to be ignored, although the rest spec lists it as a valid query parameter.

PUT /twitter/tweet/1
{
  "user": "gregmarzouka"
}

GET /twitter/_search?fielddata_fields=user

"hits": {
  "total": 1,
  "max_score": 1,
  "hits": [
     {
        "_index": "twitter",
        "_type": "tweet",
        "_id": "1",
        "_score": 1,
        "_source": {
           "user": "gregmarzouka"
        }
     }
  ]
}

Specifying it as part of the request body works as expected:

GET /twitter/_search
{
  "fielddata_fields": ["user"]
}

"hits": {
  "total": 1,
  "max_score": 1,
  "hits": [
     {
        "_index": "twitter",
        "_type": "tweet",
        "_id": "1",
        "_score": 1,
        "_source": {
           "user": "gregmarzouka"
        },
        "fields": {
           "user": [
              "gregmarzouka"
           ]
        }
     }
  ]
}