enotice Warning: implode(): Invalid arguments passed in implode() (line 113 of /CRM/Event/BAO/Participant.php). =>

I can't quite figure out why I'm hitting this because it seems like it's not new & 'should' be seen by others -maybe there is a php version in play?

When I do a back-office event registration I get the enotice in the title.

The issue appears to be that

if (in_array(key($params['role_id']), CRM_Core_DAO::acceptedSQLOperators())) {

is resolving to TRUE when key($params['role_id']) == 0

even though zero is not in the acceptedSQLOperators array.

However, adding the strict param (TRUE) to the in_array call seems to make the evaluation correct. The in_array manual (http://php.net/manual/en/function.in-array.php) comments could be summarised as 'without strict checking here be dragons'.