SIGSEGV in st_select_lex_unit::optimize

CREATE DATABASE IF NOT EXISTS HuangHe;

USE HuangHe;

CREATE TABLE v1099(c1100 INT);

INSERT v1099 SET c1100 = DEFAULT;

( SELECT * FROM v1099 LOCK IN SHARE MODE ) ORDER BY c1100 , EXISTS ( SELECT * UNION SELECT * ) = c1100;

DROP TABLE v1099;

mariadbd(_ZN18st_select_lex_unit8optimizeEv+0x3a0)[0x6131f6139910]

mariadbd(_ZN18st_select_lex_unit10exec_innerEv+0x78)[0x6131f6141948]

mariadbd(_ZN22subselect_union_engine4execEv+0xc8)[0x6131f6420d68]

mariadbd(_ZN14Item_subselect4execEv+0x4d)[0x6131f640cc3d]