https://issues.apache.org/jira/browse/SOLR-16247

Description

Null return / 0 return when searching through negative query in child filter.
!parent filters= is prone to pure negative query

This was a fix worked and developed in the hackathon at London on the 28/11/2025

Solution

Solution is to take out the query from the filter , parse it through makeQueryable() which checks if the query is negative or not, if the query is negative , we add " : " to the query and wrap it in a filter again to return the query.

Tests

Wrote a testPureNegativeQueryInChildFilters() test which child the "childFq" to a negative query and checked that we get the correct value back with the removed negative query

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended, not available for branches on forks living under an organisation)
• I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Reference Guide
• I have added a changelog entry for my change