Query returns "missing bind var __vtschemaname"

[systay]

Issuing an I_S query with the predicate WHERE table_schema = "" leads to an error instead of the expected results:

select column_name as column_name from information_schema.`columns` where table_schema = "" and table_name = "Post";
ERROR 1105 (HY000): target: beam.-.primary: vttablet: rpc error: code = InvalidArgument desc = missing bind var __vtschemaname (CallerID: rsv87azve7ogygh2o9ap)