UBSAN: null pointer passed as argument 2, which is declared to never be null in include/m_ctype.h | charset_info_st::opt_casedn | Identifier_chain2::make_sep_name_casedn_part1

CREATE PROCEDURE p0() SELECT 0 ;

call p0();

CREATE DATABASE a;

USE a;

DROP DATABASE a;

--ERROR ER_SP_DOES_NOT_EXIST

CALL foo();

/test/mtest/MDEV-34391/12.3_opt_san/include/m_ctype.h:907:17: runtime error: null pointer passed as argument 2, which is declared to never be null

/usr/include/string.h:44:28: note: nonnull attribute specified here

    #0 0x5ef6fc6d5da2 in charset_info_st::opt_casedn(char const*, unsigned long, char*, unsigned long, char) const /test/mtest/MDEV-34391/12.3_opt_san/include/m_ctype.h:907:5

    #1 0x5ef6fc6d5da2 in Identifier_chain2::make_sep_name_casedn_part1(char*, unsigned long, int) const /test/mtest/MDEV-34391/12.3_opt_san/sql/lex_ident.h:571:15

    #2 0x5ef6fc6d520a in Identifier_chain2::make_qname_casedn_part1(char*, unsigned long) const /test/mtest/MDEV-34391/12.3_opt_san/sql/lex_ident.h:643:12

    #3 0x5ef6fc6d520a in sp_cache_lookup(sp_cache**, Database_qualified_name const*) /test/mtest/MDEV-34391/12.3_opt_san/sql/sp_cache.cc:198:27

    #4 0x5ef6fc6c99a5 in Sp_handler::sp_find_routine(THD*, Database_qualified_name const*, bool) const /test/mtest/MDEV-34391/12.3_opt_san/sql/sp.cc:2254:12

    #5 0x5ef6fccf4a22 in Sql_cmd_call::execute(THD*) /test/mtest/MDEV-34391/12.3_opt_san/sql/sql_parse.cc:3241:24

    #6 0x5ef6fccfe539 in mysql_execute_command(THD*, bool) /test/mtest/MDEV-34391/12.3_opt_san/sql/sql_parse.cc:5861:26

    #7 0x5ef6fcce0780 in mysql_parse(THD*, char*, unsigned int, Parser_state*) /test/mtest/MDEV-34391/12.3_opt_san/sql/sql_parse.cc:7895:18

    #8 0x5ef6fccd7ad0 in dispatch_command(enum_server_command, THD*, char*, unsigned int, bool) /test/mtest/MDEV-34391/12.3_opt_san/sql/sql_parse.cc:1878:7

    #9 0x5ef6fcce2a46 in do_command(THD*, bool) /test/mtest/MDEV-34391/12.3_opt_san/sql/sql_parse.cc:1417:17

    #10 0x5ef6fd446a9c in do_handle_one_connection(CONNECT*, bool) /test/mtest/MDEV-34391/12.3_opt_san/sql/sql_connect.cc:1503:11

    #11 0x5ef6fd4462f6 in handle_one_connection /test/mtest/MDEV-34391/12.3_opt_san/sql/sql_connect.cc:1415:5

    #12 0x5ef6fbb2a68c in asan_thread_start(void*) crtstuff.c

    #13 0x770e9989caa3 in start_thread nptl/pthread_create.c:447:8

    #14 0x770e99929c6b in clone3 misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:78

SUMMARY: UndefinedBehaviorSanitizer: invalid-null-argument /test/mtest/MDEV-34391/12.3_opt_san/include/m_ctype.h:907:17