Memory leak upon two-phase alter event replication

--source include/master-slave.inc

CREATE TABLE t (a INT) CHARACTER SET utf8;

--error ER_BAD_FIELD_ERROR

ALTER TABLE t MODIFY a CHAR(8) DEFAULT '' CHECK (a != b), ALGORITHM=COPY;

--sync_slave_with_master

# Cleanup

--connection master

DROP TABLE t;

--source include/rpl_end.inc

Warning: Memory not freed: 32

=================================================================

==2176007==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 32 byte(s) in 1 object(s) allocated from:

    #0 0x7efc5e6b89cf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69

    #1 0x55f3cbcee623 in my_malloc /data/src/10.9/mysys/my_malloc.c:88

    #2 0x55f3ca303897 in Binary_string::real_alloc(unsigned long) /data/src/10.9/sql/sql_string.cc:45

    #3 0x55f3c9d81a6a in Binary_string::alloc(unsigned long) /data/src/10.9/sql/sql_string.h:792

    #4 0x55f3ca305d94 in String::copy(char const*, unsigned long, charset_info_st const*, charset_info_st const*, unsigned int*) /data/src/10.9/sql/sql_string.cc:474

    #5 0x55f3ca30ad93 in String::copy(String const*, charset_info_st const*, unsigned int*) /data/src/10.9/sql/sql_string.h:1006

    #6 0x55f3ca9d9714 in Item_string::Item_string(THD*, String const*, charset_info_st const*, unsigned int*, Derivation, enum_repertoire_t) /data/src/10.9/sql/item.h:4685

    #7 0x55f3ca983c9c in Item::const_charset_converter(THD*, charset_info_st const*, bool, char const*) /data/src/10.9/sql/item.cc:1399

    #8 0x55f3c9d8d404 in Item::const_charset_converter(THD*, charset_info_st const*, bool) /data/src/10.9/sql/item.h:2560

    #9 0x55f3c9d8e13c in Item_string::safe_charset_converter(THD*, charset_info_st const*) /data/src/10.9/sql/item.h:4729

    #10 0x55f3ca31c8a6 in Column_definition::prepare_stage1_convert_default(THD*, st_mem_root*, charset_info_st const*) /data/src/10.9/sql/sql_table.cc:2485

    #11 0x55f3ca31c4a1 in Column_definition::prepare_stage1_string(THD*, st_mem_root*) /data/src/10.9/sql/sql_table.cc:2448

    #12 0x55f3ca6cfff9 in Type_handler_string_result::Column_definition_prepare_stage1(THD*, st_mem_root*, Column_definition*, column_definition_type_t, Column_derived_attributes const*) const /data/src/10.9/sql/sql_type.cc:3118

    #13 0x55f3ca31c6a2 in Column_definition::prepare_stage1(THD*, st_mem_root*, column_definition_type_t, Column_derived_attributes const*) /data/src/10.9/sql/sql_table.cc:2473

    #14 0x55f3ca31e8ef in mysql_prepare_create_table_stage1 /data/src/10.9/sql/sql_table.cc:2747

    #15 0x55f3ca32a736 in mysql_create_frm_image(THD*, st_mysql_const_lex_string const&, st_mysql_const_lex_string const&, HA_CREATE_INFO*, Alter_info*, int, st_key**, unsigned int*, st_mysql_const_unsigned_lex_string*) /data/src/10.9/sql/sql_table.cc:4112

    #16 0x55f3ca32e1ad in create_table_impl /data/src/10.9/sql/sql_table.cc:4645

    #17 0x55f3ca35a304 in mysql_alter_table(THD*, st_mysql_const_lex_string const*, st_mysql_const_lex_string const*, Table_specification_st*, TABLE_LIST*, Recreate_info*, Alter_info*, unsigned int, st_order*, bool, bool) /data/src/10.9/sql/sql_table.cc:10687

    #18 0x55f3ca51e066 in Sql_cmd_alter_table::execute(THD*) /data/src/10.9/sql/sql_alter.cc:558

    #19 0x55f3ca07156f in mysql_execute_command(THD*, bool) /data/src/10.9/sql/sql_parse.cc:6014

    #20 0x55f3ca07e9b3 in mysql_parse(THD*, char*, unsigned int, Parser_state*) /data/src/10.9/sql/sql_parse.cc:8048

    #21 0x55f3cacebd80 in Query_log_event::do_apply_event(rpl_group_info*, char const*, unsigned int) /data/src/10.9/sql/log_event_server.cc:2178

    #22 0x55f3cace707e in Query_log_event::do_apply_event(rpl_group_info*) /data/src/10.9/sql/log_event_server.cc:1626

    #23 0x55f3caccf376 in Log_event::apply_event(rpl_group_info*) /data/src/10.9/sql/log_event.cc:4176

    #24 0x55f3c9dc2587 in apply_event_and_update_pos_apply /data/src/10.9/sql/slave.cc:3883

    #25 0x55f3c9dc3501 in apply_event_and_update_pos_for_parallel(Log_event*, THD*, rpl_group_info*) /data/src/10.9/sql/slave.cc:4080

    #26 0x55f3ca690e18 in rpt_handle_event /data/src/10.9/sql/rpl_parallel.cc:61

    #27 0x55f3ca699439 in handle_rpl_parallel_thread /data/src/10.9/sql/rpl_parallel.cc:1429

    #28 0x55f3cb0ec6b9 in pfs_spawn_thread /data/src/10.9/storage/perfschema/pfs.cc:2201

    #29 0x7efc5daa7fd3 in start_thread nptl/pthread_create.c:442

SUMMARY: AddressSanitizer: 32 byte(s) leaked in 1 allocation(s).