Named query causes null pointer

bug.sh

#!/bin/bash

curl -XPUT 'http://localhost:9200/myindex/' -d '
{
  "settings": {
    "index": {
      "number_of_shards": 1,
      "number_of_replicas": 0
    }
  },
  "mappings": {
    "doc": {
      "properties": {
        "datefield": {
          "type": "date"
        },
        "children": {
          "type": "nested"
        }
      }
    }
  }
}
'

echo 

curl -XPUT 'http://localhost:9200/myindex/doc/1' -d '
{
  "datefield": "2015-04-26",
  "children": [
    {
      "thing": "1stuff1"
    },
    {
      "thing": "1stuff2"
    },
    {
      "thing": "1stuff3"
    },
    {
      "thing": "1stuff4"
    }
  ]
}
'

echo 

curl -XPUT 'http://localhost:9200/myindex/doc/2' -d '
{
  "datefield": "2015-04-27",
  "children": [
    {
      "thing": "2stuff1"
    },
    {
      "thing": "2stuff2"
    },
    {
      "thing": "2stuff3"
    },
    {
      "thing": "2stuff4"
    },
    {
      "thing": "2stuff5"
    }
  ]
}
'

echo 

curl -XPUT 'http://localhost:9200/myindex/doc/3' -d '
{
  "datefield": "2015-04-28",
  "children": [
    {
      "thing": "3stuff1"
    },
    {
      "thing": "3stuff2"
    },
    {
      "thing": "3stuff3"
    },
    {
      "thing": "3stuff4"
    },
    {
      "thing": "3stuff5"
    },
    {
      "thing": "3stuff6"
    }
  ]
}
'

echo 

# index a bunch more documents
for id in `seq 7 4000`;
do
	curl -XPUT "http://localhost:9200/myindex/doc/$id" -d '{}' > /dev/null 2>&1
done 



# give it a chance to refresh the readers etc
read -n1 -r -p "Press any key to perform search..." key


### this should return a failure due to a null pointer.
curl -XGET 'http://localhost:9200/myindex/doc/_search' -d '
{
  "query": {
    "range": {
      "datefield": {
        "gte": "2015-04-27",
        "_name": "date1",
        "lte": "2015-04-28"
      }
    }
  }
}
'