javanna 4805250ecf Throw ParsingException if a query is wrapped in an array ...

Our parsing code accepted up until now queries in the following form (note that the query starts with `[`:

```
{
    "bool" : [
        {
          "must" : []
        }
    ]
}
```

This would lead to a null pointer exception as most parsers assume that the field name ("must" in this example) is the first thing that can be found in a query if its json is valid, hence always non null while parsing. Truth is that the additional array layer doesn't make the json invalid, hence the following code fragment would cause NPE within ParseField, because null gets passed to `parseContext.isDeprecatedSetting`:

```
if (token == XContentParser.Token.FIELD_NAME) {
    currentFieldName = parser.currentName();
} else if (parseContext.isDeprecatedSetting(currentFieldName)) {
    // skip
} else if (token == XContentParser.Token.START_OBJECT) {
```

We could add null checks in each of our parsers in lots of places, but we rely on `currentFieldName` being non null in all of our parsers, and we should consider it a bug when these unexpected situations are not caught explicitly. It would be best to find a way to prevent such queries altogether without changing all of our parsers.

The reason why such a query goes through is that we've been allowing a query to start with either `[` or `{`. The only reason I found is that we accept `match_all : []`. This seems like an undocumented corner case that we could drop support for. Then we can be stricter and accept only `{` as start token of a query. That way the only next token that the parser can encounter if the json is valid (otherwise the json parser would barf earlier) is actually a field_name, hence the assumption that all our parser makes hold.

The downside of this is simply dropping support for `match_all : []`

Relates to #12887

2016-08-03 17:05:14 +02:00

..

src

Throw ParsingException if a query is wrapped in an array

2016-08-03 17:05:14 +02:00

build.gradle

Move netty transport and http into a module

2016-07-11 22:21:29 +02:00