No error shown on non-existing cluster setting

[RobinUS2]

For example setting the default number of shards. This throws no exception, even though it is not supported.

CURL Apply change: curl -XPUT localhost:9200/_cluster/settings -d '{ "persistent" : { "index.number_of_shards" : 2 } }'

Change Response {"acknowledged":true,"persistent":{},"transient":{}}

CURL List settings curl -XGET localhost:9200/_cluster/settings

Settings Response {"persistent":{},"transient":{}}

Mailing list topic: https://groups.google.com/forum/#!topic/elasticsearch/uOXvRid-VoA

[clintongormley]

Closed in favour of #6732