Segmentation fault while casting empty string to jsquery.

[d0d63r]

Here is steps for issue reproducing. Every "execute" performs successfully until 6th try. Reproduced at PostgreSQL version 10.5, jsquery version 1.1.0.

create extension jsquery;

prepare a as (select $1::text::jsquery);

execute a('');
execute a('');
execute a('');
execute a('');
execute a('');
execute a('');