Our query DSL supports empty queries (`{}`), which have a different meaning depending on the query that holds it, either ignored, match_all or match_none. We deprecated the support for empty queries in 5.0, where we log a deprecation warning wherever they are used.
The way we supported it once we moved query parsing to the coordinating node was having an Optional<QueryBuilder> return type in all of our parse methods (called fromXContent). See #17624. The central place for this was QueryParseContext#parseInnerQueryBuilder. We can now remove all the optional return types and simply throw an exception whenever an empty query is found.
Currently, the `terms` query is just syctactic sugar for a `bool` query when
used in a query context. This change proposes to always generate the same query
in query and filter contexts, which is less confusing.
The `type` parameter has always been accepted by the search_shards api, probably to make the api and its urls the same as search. Truth is that the type never had any effect, it's been ignored from day one while accepting it may make users think that we actually do something with it.
This commit removes support for the type parameter from the REST layer and the Java API. Backwards compatibility is maintained on the transport layer though.
The new added serialization test also uncovered a bug in the java API where the `ClusterSearchShardsRequest` could be created with no arguments, but the indices were required to be not null otherwise the request couldn't be serialized as `writeTo` would throw NPE. Fixed by setting a default value (empty array) for indices.
This changes only the query parsing behavior to be strict when searching on
boolean values. We continue to accept the variety of values during index time,
but searches will only be parsed using `"true"` or `"false"`.
Resolves#21545
The collect_payloads parameter of the span_near query was previously
deprecated with the intention to be removed. This commit removes this
parameter.
Relates #20385