Bug elasticsearch: "match uses the wrong field"

gistfile1.txt

#!/usr/bin/env bash

docker run -tid -p 9200:9200 elasticsearch:1.7.3

sleep 5

ES_URI="http://192.168.99.100:9200"

curl -XDELETE ${ES_URI}/test

curl -XPOST ${ES_URI}/test -d '
{
	"settings": {
        "number_of_shards": "1",
        "number_of_replicas": "1"
    },
	"mappings" : {
		"title" : {
			"properties" : {
				"alias" : {
					"type" : "string",
					"fields" : {
						"simple" : {
							"type" : "string"
						}
					}
				}
			}
		}
	}
}'

curl -XPUT ${ES_URI}/test/title/toto -d '
{
	"alias" : "coca"
}'

sleep 1

echo ""

# This should return nothing but returns "toto" document
curl -XGET ${ES_URI}/test/_search?q=title.simple:coca

echo ""

# This returns nothing
curl -XGET ${ES_URI}/test/_search?q=toto.simple:coca

echo ""

# This returns "toto" document
curl -XGET ${ES_URI}/test/_search?q=alias.simple:coca

echo ""

# This should return nothing but returns "toto" document
curl -XPOST ${ES_URI}/test/_search -d '
{
	"query" : {
		"match" : {
			"title.simple" : "coca"
		}
	}
}
'