Crash with a stored aggregate function returning INET6

DELIMITER $$

CREATE OR REPLACE AGGREGATE FUNCTION aggregate_min_inet6(x INET6) RETURNS INET6

BEGIN

  DECLARE res INET6 DEFAULT NULL;

  DECLARE CONTINUE HANDLER FOR NOT FOUND

    RETURN res;

  LOOP

    FETCH GROUP NEXT ROW;

    IF (res IS NULL) OR (res > x) THEN

      SET res= x;

    END IF;

  END LOOP;

END;

$$

DELIMITER ;

CREATE OR REPLACE TABLE t1 (name CHAR(30), val INET6);

INSERT INTO t1 VALUES ('a', '::05');

INSERT INTO t1 VALUES ('a', '::03');

INSERT INTO t1 VALUES ('b', '::01');

INSERT INTO t1 VALUES ('b', '::02');

INSERT INTO t1 VALUES ('b', '::05');

CREATE OR REPLACE TABLE t2 (name CHAR(30), val INET6);

INSERT INTO t2 SELECT name, aggregate_min_inet6(val) pc FROM t1 GROUP BY name;

#0  0x00007ffff763c625 in raise () from /lib64/libc.so.6

#1  0x00007ffff76258d9 in abort () from /lib64/libc.so.6

#2  0x00007ffff76257a9 in __assert_fail_base.cold () from /lib64/libc.so.6

#3  0x00007ffff7634a66 in __assert_fail () from /lib64/libc.so.6

#4  0x0000000000752144 in Item::val_native (this=0x7fff98097c70, 

    thd=0x7fff98000d48, to=0x7ffff43962e0)

    at /home/bar/maria-git/server.10.5.vg/sql/item.h:1362

#5  0x0000000001579e07 in Type_handler_inet6::Item_save_in_field (

    this=0x2a671b0 <type_handler_inet6>, item=0x7fff98097c70, 

    field=0x7fffc400a460, no_conversions=false)

    at /home/bar/maria-git/server.10.5.vg/plugin/type_inet/sql_type_inet.h:586

#6  0x0000000000bf7715 in Item::save_in_field (this=0x7fff98097c70, 

    field=0x7fffc400a460, no_conversions=false)

    at /home/bar/maria-git/server.10.5.vg/sql/item.cc:6605

#7  0x00000000007e00b4 in fill_record (thd=0x7fff98000d48, 

    table=0x7fff9809cdc8, ptr=0x7fff9809a890, values=..., ignore_errors=true, 

    use_value=false) at /home/bar/maria-git/server.10.5.vg/sql/sql_base.cc:8719

#8  0x00000000007e023f in fill_record_n_invoke_before_triggers (