Facet summary of empty collection returns internal error

[lukashornych]

When facet summary of certain reference that references empty collection AND the facet statistics are filtered, the evitaDB returns

Global index of entity {collection name} unexpectedly not found!

Minimal example query is this:

{
    queryProduct{
        extraResults {
            facetSummary {
                groups {
                    facetStatistics(filterBy: {
                        referenceTagsHaving: {
                            entityHaving: {
                                attributeCodeEquals: "COLLECTION_GROUP"
                            }
                        }
                    }) {
                        facetEntity {
                            primaryKey
                            attributes {
                                name
                                url
                                description
                            }
                        }
                    }
                }
            }
        }
    }
}

I understand why it throws this error but I think it should return empty facet statistics like it does without the filter.

[novoj]

@lukashornych I've added test io.evitadb.api.EntityByFacetFilteringFunctionalTest#shouldReturnEmptyFacetSummaryForEmptyCollection, but I cannot reproduce the described behaviour. See related branch.

Does this situation still occur in current version?