Failing mvel/geopoint array

gistfile1.js

// Query:
{
  "query":{
    "match_all":{}
  },
  "script_fields":{
    "test1":{
      "script":"i = 0; n = 0; d = 0; if (doc['locs'].values.length > 0) { d = doc['locs'].lons[i]; } d;"
    }
  },
  "fields":["locs",
    "test1"
  ]
}
// Error (from elasticsearch-head):
{

    * took: 13
    * timed_out: false
    * _shards: {
          o total: 5
          o successful: 4
          o failed: 1
          o failures: [
                + {
                      # reason: RemoteTransportException[[Bizarnage][inet[/10.194.17.235:9300]][search/phase/fetch/id]]; nested: RuntimeException[cannot invoke getter: getLons [declr.class: org.elasticsearch.index.mapper.xcontent.geo.GeoPointDocFieldData; act.class: org.elasticsearch.index.mapper.xcontent.geo.GeoPointDocFieldData] (see trace)]; nested: ClassCastException[[D cannot be cast to [Ljava.lang.Object;]; 
                  }
            ]
      }
    * hits: {
          o total: 198
          o max_score: 1
          o hits: [ ]
      }

}