Prepared statements with st_convexhull hang and eat 100% cpu

*************************** 6. row ***************************

      Id: 9

    User: root

    Host: localhost:7859

      db: test

 Command: Query

    Time: 69

   State: NULL

    Info: do st_convexhull(st_aswkb(multipoint(point(-11702,15179),point(-5031,27960),point(-30557,11158),point(-27804,30314))))

Progress: 0.000

prepare s from 'do st_convexhull(st_aswkb(multipoint(point(-11702,15179),point(-5031,27960),point(-30557,11158),point(-27804,30314))))';

execute s;

execute s;