Boosts don't seem to work for prefix queries

#!/bin/bash

curl -XDELETE "http://localhost:9200/test?pretty" -s
curl -XPOST "http://localhost:9200/test?pretty" -s
curl -XGET 'http://localhost:9200/_cluster/health?pretty=true&wait_for_status=yellow'


curl -XPOST "http://localhost:9200/test/test/1?pretty" -d '{"foo": "findme"}'
curl -XPOST "http://localhost:9200/test/test/2?pretty" -d '{"bar": "findme"}'
curl -XPOST http://localhost:9200/test/_refresh?pretty


curl -XPOST "http://localhost:9200/test/test/_search?pretty&explain" -d '{
  "query": {
    "query_string": {
      "query": "findm*",
      "fields": ["foo^20", "bar"]
    }
  }
}'

# {
#   "took" : 2,
#   "timed_out" : false,
#   "_shards" : {
#     "total" : 5,
#     "successful" : 5,
#     "failed" : 0
#   },
#   "hits" : {
#     "total" : 2,
#     "max_score" : 1.0,
#     "hits" : [ {
#       "_shard" : 3,
#       "_node" : "sVwRSdM5RuCN77Eait9U5Q",
#       "_index" : "test",
#       "_type" : "test",
#       "_id" : "2",
#       "_score" : 1.0, "_source" : {"bar": "findme"},
#       "_explanation" : {
#         "value" : 1.0,
#         "description" : "max of:",
#         "details" : [ {
#           "value" : 1.0,
#           "description" : "ConstantScore(bar:findm*), product of:",
#           "details" : [ {
#             "value" : 1.0,
#             "description" : "boost"
#           }, {
#             "value" : 1.0,
#             "description" : "queryNorm"
#           } ]
#         } ]
#       }
#     }, {
#       "_shard" : 2,
#       "_node" : "sVwRSdM5RuCN77Eait9U5Q",
#       "_index" : "test",
#       "_type" : "test",
#       "_id" : "1",
#       "_score" : 1.0, "_source" : {"foo": "findme"},
#       "_explanation" : {
#         "value" : 1.0,
#         "description" : "max of:",
#         "details" : [ {
#           "value" : 1.0,
#           "description" : "ConstantScore(foo:findm*^20.0)^20.0, product of:",
#           "details" : [ {
#             "value" : 20.0,
#             "description" : "boost"
#           }, {
#             "value" : 0.05,
#             "description" : "queryNorm"
#           } ]
#         } ]
#       }
#     } ]
#   }
# }


curl -XPOST "http://localhost:9200/test/test/_search?pretty&explain" -d '{
  "query": {
    "bool": {
      "should": [ {
        "prefix": {
          "foo": {
            "value": "findm",
            "boost": 20
          }
        }
      }, {
        "prefix": {
          "bar": "findm"
        }
      } ]
    }
  }
}'


# {
#   "took" : 6,
#   "timed_out" : false,
#   "_shards" : {
#     "total" : 5,
#     "successful" : 5,
#     "failed" : 0
#   },
#   "hits" : {
#     "total" : 2,
#     "max_score" : 0.5,
#     "hits" : [ {
#       "_shard" : 3,
#       "_node" : "sVwRSdM5RuCN77Eait9U5Q",
#       "_index" : "test",
#       "_type" : "test",
#       "_id" : "2",
#       "_score" : 0.5, "_source" : {"bar": "findme"},
#       "_explanation" : {
#         "value" : 0.5,
#         "description" : "product of:",
#         "details" : [ {
#           "value" : 1.0,
#           "description" : "sum of:",
#           "details" : [ {
#             "value" : 1.0,
#             "description" : "ConstantScore(bar:findm*), product of:",
#             "details" : [ {
#               "value" : 1.0,
#               "description" : "boost"
#             }, {
#               "value" : 1.0,
#               "description" : "queryNorm"
#             } ]
#           } ]
#         }, {
#           "value" : 0.5,
#           "description" : "coord(1/2)"
#         } ]
#       }
#     }, {
#       "_shard" : 2,
#       "_node" : "sVwRSdM5RuCN77Eait9U5Q",
#       "_index" : "test",
#       "_type" : "test",
#       "_id" : "1",
#       "_score" : 0.5, "_source" : {"foo": "findme"},
#       "_explanation" : {
#         "value" : 0.5,
#         "description" : "product of:",
#         "details" : [ {
#           "value" : 1.0,
#           "description" : "sum of:",
#           "details" : [ {
#             "value" : 1.0,
#             "description" : "ConstantScore(foo:findm*^20.0)^20.0, product of:",
#             "details" : [ {
#               "value" : 20.0,
#               "description" : "boost"
#             }, {
#               "value" : 0.05,
#               "description" : "queryNorm"
#             } ]
#           } ]
#         }, {
#           "value" : 0.5,
#           "description" : "coord(1/2)"
#         } ]
#       }
#     } ]
#   }
# }

echo