The class org.alfresco.module.org_alfresco_module_rm.search.RecordsManagementSearchParameters deactivates at line 385 all auditing of searches in Alfresco by deactivating the converter from SearchParameters to String.
As per MNT-14795 (ACE-4258 https://issues.alfresco.com/jira/browse/ACE-4258) There was a problem with the attribute "limit" of the class SearchParameters that was changed in Alfresco 5.1.a-EA from a primitive "int" to an "Integer" object. Since "limit" was made into an object it could now be null. The method hashCode() in SearchParameters depended on it not being null. That problem became visible while testing the use of Alfresco 5.1.a-EA with Records Management.
A snippet was inserted at the end of RecordsManagementSearchParameters to deactivate that single call to hashCode that made the problem visible. (commit https://github.com/Alfresco/records-management/commit/fa6a1dcde4648137b852864448d5f51282843814) and a task (https://issues.alfresco.com/jira/browse/RM-2635) added in 2015 to remove this once the bug was fixed.
In addition, the change to the limit attribute that caused this seems to have been reverted since. In the current version limit is no longer an Integer object but a primitive int like before (see https://github.com/Alfresco/alfresco-data-model/blob/master/src/main/java/org/alfresco/service/cmr/search/SearchParameters.java#L140).
The workaround for the bug that is no longer there is still included in Records Management and disables the audit for searches: https://github.com/Alfresco/records-management/blob/master/rm-community/rm-community-repo/source/java/org/alfresco/module/org_alfresco_module_rm/search/RecordsManagementSearchParameters.java#L385
The workaround put in place in https://issues.alfresco.com/jira/browse/RM-2601 should have been removed as per https://issues.alfresco.com/jira/browse/RM-2635, so the audit for search is not available.
The workaround put in place in https://issues.alfresco.com/jira/browse/RM-2601 was not removed as it should have been per https://issues.alfresco.com/jira/browse/RM-2635, so the audit for searches is disabled. In addition the change limit attribute that was the initial cause of the problem, seems to have been reverted in the current version.