Server crash in Item_ref::transform

DROP DATABASE IF EXISTS nonprep_only;

CREATE DATABASE nonprep_only;

USE nonprep_only;

SET optimizer_switch='condition_pushdown_for_derived=on,condition_pushdown_from_having=on,derived_merge=on';

CREATE TABLE t(a INT,b INT);

INSERT INTO t VALUES (1,1),(2,2),(3,3),(NULL,4);

DROP VIEW IF EXISTS vv;

CREATE VIEW vv AS

  SELECT IFNULL(CAST(a AS CHAR), CURRENT_USER()) x,b

  FROM (SELECT * FROM (SELECT a,b FROM t GROUP BY 0.1) q1) q2;

DROP PROCEDURE IF EXISTS p_nonprep;

DELIMITER $$

CREATE PROCEDURE p_nonprep()

BEGIN

  SELECT * FROM vv WHERE IFNULL(x, CURRENT_USER()) IN (x, CURRENT_USER());

END$$

DELIMITER ;

CALL p_nonprep();

CALL p_nonprep();

CALL p_nonprep();

/public/home/mariadb-12.3.1/sql/item.cc:8857:3: runtime error: load of null pointer of type 'struct Item *'

    #0  Item_ref::transform(...)                              sql/item.cc:8857

    #1  Item_ref::transform(...)                              sql/item.cc:8860

    #2  Item_args::transform_args(...)                        sql/item_func.cc:532

    #3  Item_func::transform(...)                             sql/item_func.cc:568

    #4  Item_args::transform_args(...)                        sql/item_func.cc:532

    #5  Item_func::transform(...)                             sql/item_func.cc:568

    #6  Item_ref::transform(...)                              sql/item.cc:8860

    #7  Item_args::transform_args(...)                        sql/item_func.cc:532

    #8  Item_func::transform(...)                             sql/item_func.cc:568

    #9  Item_ref::transform(...)                              sql/item.cc:8860

    #10 Item_args::transform_args(...)                        sql/item_func.cc:532

    #11 Item_func::transform(...)                             sql/item_func.cc:568

    #12 pushdown_cond_for_derived(...)                        sql/sql_derived.cc:1655

    #13 JOIN::optimize_inner()                                sql/sql_select.cc:2580

    #14 JOIN::optimize()                                      sql/sql_select.cc:2016

    #15 mysql_select(...)                                     sql/sql_select.cc:5425

    #16 handle_select(...)                                    sql/sql_select.cc:636

    #17 execute_sqlcom_select                                 sql/sql_parse.cc:6212

    #18 mysql_execute_command(...)                            sql/sql_parse.cc:3987

    #19 Prepared_statement::execute(...)                      sql/sql_prepare.cc:5344

    #20 Prepared_statement::execute_loop(...)                 sql/sql_prepare.cc:4703

    #21 mysql_sql_stmt_execute                                sql/sql_prepare.cc:3635

    #22 mysql_sql_stmt_execute(THD*)                          sql/sql_prepare.cc:3649

    #23 mysql_execute_command(...)                            sql/sql_parse.cc:4003

    #24 mysql_parse(...)                                      sql/sql_parse.cc:7940

    #25 dispatch_command(...)                                 sql/sql_parse.cc:1896

    #26 do_command(...)                                       sql/sql_parse.cc:1432

    #27 do_handle_one_connection(...)                         sql/sql_connect.cc:1503

    #28 handle_one_connection                                 sql/sql_connect.cc:1415

    #29 pfs_spawn_thread                                      storage/perfschema/pfs.cc:2198