REST Web Service ./events/custom/delete_events should not delete all events if the "ids" parameter is empty

Current Situation

The web service ./events/custom/delete_events deletes all events if the parameter ids which is an array is empty in the request body.
The web service expects numbers in the ids array.
If there are strings in this array that cannot be converted to a number, they are discarded, so that an empty array can unintentionally be created and all events can be deleted.

Desired Behavior

If the ids array is empty then no event will be deleted.