Fix native :fields behavior mismatch with rest

[dspiteself]

When processing results from a search query 'convert-fields-result' called getValue instead of getValues. This caused the first of the values to be returned. This behavior is inconsistent with the behavior of the rest api which always returns a vector.

[dspiteself]

Even though tests pass. It is extremely likely this breaks code in the wild.

[favila]

What follows is a higher-level restatement of the problem this patch addresses.

Currently, if you query elasticsearch specifying "fields", e.g.

{"fields": ["fieldA", "fieldB"],
 "query": ...}

With the elastich (and elasticsearch) REST client the result for fields will always be arrays:

// "fields" result from REST
{"hits":
  {"hits": [
    {"fields": {
      "fieldA":["valueA1", "valueA2"],
      "fieldB":["valueB1"]
    }}
  ]}
}

If you issue the same query using the native client, the result for fields will always be scalar and only supply the first value:

// fields result from native client (WRONG)
{"hits":
  {"hits": [
    {"fields": {
      "fieldA":"valueA1", // "valueA2" missing!
      "fieldB":"valueB1"
    }}
  ]}
}

The attached patch makes the second (wrong, native client) result look like the first (correct, REST) result.

[michaelklishin]

I understand and the right thing to do here is to fix things. Would you mind submitting the same change against 2.1.x-stable? I can cut a point release shortly after. Thank you.

[michaelklishin]

Actually, don't worry, the change is a single commit so I can trivially cherry pick it :)

[michaelklishin]

2.2.1 is up on Clojars.