GIS error message doesn't show the wrong value, just the type.

create table t1(a polygon NOT NULL)engine=innodb;
insert into t1 values (ST_geomfromtext("point(0 1)"));
ERROR 1366 (22007): Incorrect POLYGON value: 'POINT' for column `test`.`t1`.`a` at row 1

So justh the type of the value is seen in the error message, not the full value.