If an empty leprop parameter is passed to list=logevents, the query contains many empty sets. For example, this query gives me:
{ "batchcomplete": "", "continue": { "lecontinue": "20160924214304|77568834", "continue": "-||" }, "query": { "logevents": [ {}, {}, {}, {}, {}, {}, {}, {}, {}, {} ] } }
There should either be some omnipresent leprop value(s) or this should be an error. From performance point of view, the database query still joins the logging, user and page tables, even for this trivial query.