While playing with ElasticSearch faceting (and having tests failing due to that), I noticed that for Longs and Dates, the preexisting range faceting doesn't take into account facetRequest.hasZeroCountsIncluded().

See
https://github.com/hibernate/hibernate-search/blob/master/engine/src/main/java/org/hibernate/search/query/engine/impl/QueryHits.java#L308
and a few lines below for floating point ranges which take into account this very parameter.