java.lang.ClassCastException when "properties" set to []

[edast]

Some languages (e.g. PHP) don't have Map type just Array, so if "properties" or "fields" in mapping are empty - encoding it to json will result in array [], and not object {}
until 0.9 this was not an issue, but now elasticsearch refuses to create mapping with exception:

Caused by: java.lang.ClassCastException: java.util.ArrayList cannot be cast to java.util.Map
  at org.elasticsearch.index.mapper.object.ObjectMapper$TypeParser.parse(ObjectMapper.java:216)
  at org.elasticsearch.index.mapper.object.ObjectMapper$TypeParser.parseProperties(ObjectMapper.java:258)
  at org.elasticsearch.index.mapper.object.ObjectMapper$TypeParser.parse(ObjectMapper.java:216)

sample mapping:

curl -XPUT 'localhost:9200/test' -d '{
    "mappings": {
        "test": {
            "_source": {
                "enabled": true
            },
            "properties": {
                "notes": {
                    "index": "no",
                    "type": "nested",
                    "include_in_all": true,
                    "enabled": true,
                    "properties": []
                }
            }
        }
    },
    "settings": {
        "number_of_shards": 1,
        "number_of_replicas": 0
    }
}'

this issue could be resolved by adding addition check to see if fieldNode is instance of Map:

-    } else if (fieldName.equals("properties")) {
+    } else if (fieldName.equals("properties") && fieldNode instanceof Map) {

[evillemez]

Yeah, this affected me as well, took a bit of time to track down to the root cause.

[kimchy]

Aye, it should be fixed. I think that purposed solution might not make sense, because we need to raise a failure if an array is provided with values in properties, but maybe we can optimize for the array with 0 elements type case.

[kimchy]

fixed in upcoming 1.2, see #6006

[edast]

could you also change src/main/java/org/elasticsearch/index/mapper/core/TypeParsers.java (line 66) to support empty array for "fields"?

   } else if (fieldName.equals("fields")) {
       Map<String, Object> fieldsNode = (Map<String, Object>) fieldNode;