ES Terms Facet send back bad count results

01-create.sh

# Dropping index and Creating articles
curl -X DELETE "http://localhost:9200/articles"
curl -X POST "http://localhost:9200/articles/article" -d '{"tags" : ["one", "two", "three", "four", "five", "six", "seven"]}'
curl -X POST "http://localhost:9200/articles/article" -d '{"tags" : ["two", "three", "four", "five", "six", "seven"]}'
curl -X POST "http://localhost:9200/articles/article" -d '{"tags" : ["three", "four", "five", "six", "seven"]}'
curl -X POST "http://localhost:9200/articles/article" -d '{"tags" : ["four", "five", "six", "seven"]}'
curl -X POST "http://localhost:9200/articles/article" -d '{"tags" : ["five", "six", "seven"]}'
curl -X POST "http://localhost:9200/articles/article" -d '{"tags" : ["six", "seven"]}'
curl -X POST "http://localhost:9200/articles/article" -d '{"tags" : ["seven"]}'

# Classic search with terms facet
curl -X POST "http://localhost:9200/articles/_search?pretty=true" -d '
  {
    "query" : { "match_all" : { } },
    "facets" : {
      "f_tags" : { "terms" : {"field" : "tags"} }
    }
  }
'

02-result.json

{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 7,
    "max_score" : 1.0,
    "hits" : [ {
      "_index" : "articles",
      "_type" : "article",
      "_id" : "gkgAyLN6QWuxSyBLxxknIw",
      "_score" : 1.0, "_source" : {"tags":["two","three","four","five","six","seven"]}
    }, {
      "_index" : "articles",
      "_type" : "article",
      "_id" : "swVlq23SS9aoC8uHNB_LRA",
      "_score" : 1.0, "_source" : {"tags":["one","two","three","four","five","six","seven"]}
    }, {
      "_index" : "articles",
      "_type" : "article",
      "_id" : "oColEdY-SUmMPWvBWBEneQ",
      "_score" : 1.0, "_source" : {"tags":["six","seven"]}
    }, {
      "_index" : "articles",
      "_type" : "article",
      "_id" : "hk-9osIlRViESqEF7WPj_w",
      "_score" : 1.0, "_source" : {"tags":["three","four","five","six","seven"]}
    }, {
      "_index" : "articles",
      "_type" : "article",
      "_id" : "Ki9KA036TI6n7f6vD2gGWA",
      "_score" : 1.0, "_source" : {"tags":["four","five","six","seven"]}
    }, {
      "_index" : "articles",
      "_type" : "article",
      "_id" : "_bFnruq4TdyJQjHH5bTMrg",
      "_score" : 1.0, "_source" : {"tags":["five","six","seven"]}
    }, {
      "_index" : "articles",
      "_type" : "article",
      "_id" : "k1FzqoBwQ82PYNa1jgE-Tg",
      "_score" : 1.0, "_source" : {"tags":["seven"]}
    } ]
  },
  "facets" : {
    "f_tags" : {
      "_type" : "terms",
      "missing" : 0,
      "terms" : [ {
        "term" : "seven",
        "count" : 7
      }, {
        "term" : "six",
        "count" : 6
      }, {
        "term" : "three",
        "count" : 3
      }, {
        "term" : "four",
        "count" : 3
      }, {
        "term" : "five",
        "count" : 3
      } ]
    }
  }
}