Description
NULL-aware ANTI join (https://issues.apache.org/jira/browse/SPARK-32290) detects NULL join keys during building the map for `HashedRelation`, and will immediately return `HashedRelationWithAllNullKeys` without taking care of the map built already. Before returning `HashedRelationWithAllNullKeys`, the map needs to be freed properly to save memory and keep memory accounting correctly.
User 'c21' has created a pull request for this issue:
https://github.com/apache/spark/pull/32939