Having multiple indexers with the same id registered via multiple custom fields might cause the issue with reindexing due to CustomFieldIndexerAdapter doesn't delegate correctly.
- It uses equals() and hashCode() from Object instead of delegating to the wrapped object which means that custom field indexers returned from com.atlassian.jira.issue.index.managers.FieldIndexerManagerImpl.getAllIssueIndexers() are no longer deduped.
CustomFieldIndexerAdapter delegates correctly
CustomFieldIndexerAdapter doesn't delegate correctly
The below exception is thrown in the Jira file during reindexing: