Filtered documents still get passed to plugin

Elastic Stack Elasticsearch
1

In our current set-up we use a function_score in combination with a native Java plugin to calculate the price of lease cars. I would like to add a not filter around it. Currently it looks something like this:

"query": {
  "filtered": {
    "filter": {
      "not": {
        "term": {
          "make.facet": "Audi"
        }
      }
    },
    "query": {
      "function_score": {
        "functions": [
          {
            "script_score": {
              "script": "native-score",
              "lang": "native",
              "params": {...}
            }
          }
        ],
        "query": {
          "match_all": {}
        },
        "boost_mode": "replace",
        "min_score": 0
      }
    }
  }
}

The problem I am having though is that for the filtered documents the plugin is still called, but without the expected fields. Right now I have solved this with a dirty check in the plugin to see if any of the required fields are set, and if not I simply return null to prevent ending up with NPE's. Surely this isn't the best way to fix this. We are using elasticsearch 1.7.5. Is this a bug, or can I re-organize my query in such a way that it works as expected?

2

FWIW; our query generator places the filter inside the query of function_score. This has the same unwanted effect with the plugin.