ASAN errors in ha_mroonga::storage_encode_key_fixed_size_string upon using prefixed key

INSTALL SONAME 'ha_mroonga';

CREATE TABLE t (a char(128), KEY(a(32))) ENGINE=Mroonga;

INSERT INTO t VALUES ('foo'),('bar');

DELETE FROM t WHERE a IS NULL;

# Cleanup

DROP TABLE t;

UNINSTALL SONAME 'ha_mroonga';

==3640855==ERROR: AddressSanitizer: use-after-poison on address 0x621000116d82 at pc 0x7fc527c4814b bp 0x7fc51f9072c0 sp 0x7fc51f906a70

READ of size 128 at 0x621000116d82 thread T5

    #0 0x7fc527c4814a in __interceptor_memcpy ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827

    #1 0x7fc51e58fb6c in ha_mroonga::storage_encode_key_fixed_size_string(Field*, unsigned char const*, unsigned char*, unsigned int*) /data/src/10.4/storage/mroonga/ha_mroonga.cpp:11586

    #2 0x7fc51e59680b in ha_mroonga::storage_encode_key(Field*, unsigned char const*, unsigned char*, unsigned int*) /data/src/10.4/storage/mroonga/ha_mroonga.cpp:12078

    #3 0x7fc51e557e4c in ha_mroonga::storage_records_in_range(unsigned int, st_key_range*, st_key_range*) /data/src/10.4/storage/mroonga/ha_mroonga.cpp:7525

    #4 0x7fc51e559495 in ha_mroonga::records_in_range(unsigned int, st_key_range*, st_key_range*) /data/src/10.4/storage/mroonga/ha_mroonga.cpp:7636

    #5 0x55bebfb27717 in handler::multi_range_read_info_const(unsigned int, st_range_seq_if*, void*, unsigned int, unsigned int*, unsigned int*, Cost_estimate*) /data/src/10.4/sql/multi_range_read.cc:126

    #6 0x7fc51e59ab7c in ha_mroonga::storage_multi_range_read_info_const(unsigned int, st_range_seq_if*, void*, unsigned int, unsigned int*, unsigned int*, Cost_estimate*) /data/src/10.4/storage/mroonga/ha_mroonga.cpp:12375

    #7 0x7fc51e59af22 in ha_mroonga::multi_range_read_info_const(unsigned int, st_range_seq_if*, void*, unsigned int, unsigned int*, unsigned int*, Cost_estimate*) /data/src/10.4/storage/mroonga/ha_mroonga.cpp:12396

    #8 0x55bec020e275 in check_quick_select /data/src/10.4/sql/opt_range.cc:11258

    #9 0x55bec01f4b14 in get_key_scans_params /data/src/10.4/sql/opt_range.cc:7467

    #10 0x55bec01d7c22 in SQL_SELECT::test_quick_select(THD*, Bitmap<64u>, unsigned long long, unsigned long long, bool, bool, bool, bool) /data/src/10.4/sql/opt_range.cc:2943

    #11 0x55bebf95ab5f in SQL_SELECT::check_quick(THD*, bool, unsigned long long) /data/src/10.4/sql/opt_range.h:1654

    #12 0x55bec0297ee3 in mysql_delete(THD*, TABLE_LIST*, Item*, SQL_I_List<st_order>*, unsigned long long, unsigned long long, select_result*) /data/src/10.4/sql/sql_delete.cc:530

    #13 0x55bebf67a975 in mysql_execute_command(THD*) /data/src/10.4/sql/sql_parse.cc:4815

    #14 0x55bebf690a76 in mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) /data/src/10.4/sql/sql_parse.cc:8010

    #15 0x55bebf666d41 in dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool) /data/src/10.4/sql/sql_parse.cc:1857

    #16 0x55bebf6638b0 in do_command(THD*) /data/src/10.4/sql/sql_parse.cc:1378

    #17 0x55bebfa62e0f in do_handle_one_connection(CONNECT*) /data/src/10.4/sql/sql_connect.cc:1420

    #18 0x55bebfa62726 in handle_one_connection /data/src/10.4/sql/sql_connect.cc:1324

    #19 0x55bec06d2e1f in pfs_spawn_thread /data/src/10.4/storage/perfschema/pfs.cc:1869

    #20 0x7fc5276a7fd3 in start_thread nptl/pthread_create.c:442

    #21 0x7fc5277285bb in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

0x621000116d82 is located 130 bytes inside of 4064-byte region [0x621000116d00,0x621000117ce0)

allocated by thread T5 here:

    #0 0x7fc527cb89cf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69

    #1 0x55bec121c882 in my_malloc /data/src/10.4/mysys/my_malloc.c:101

    #2 0x55bec11f92a8 in alloc_root /data/src/10.4/mysys/my_alloc.c:251

    #3 0x55bec01d6083 in SQL_SELECT::test_quick_select(THD*, Bitmap<64u>, unsigned long long, unsigned long long, bool, bool, bool, bool) /data/src/10.4/sql/opt_range.cc:2752

    #4 0x55bebf95ab5f in SQL_SELECT::check_quick(THD*, bool, unsigned long long) /data/src/10.4/sql/opt_range.h:1654

    #5 0x55bec0297ee3 in mysql_delete(THD*, TABLE_LIST*, Item*, SQL_I_List<st_order>*, unsigned long long, unsigned long long, select_result*) /data/src/10.4/sql/sql_delete.cc:530

    #6 0x55bebf67a975 in mysql_execute_command(THD*) /data/src/10.4/sql/sql_parse.cc:4815

    #7 0x55bebf690a76 in mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) /data/src/10.4/sql/sql_parse.cc:8010

    #8 0x55bebf666d41 in dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool) /data/src/10.4/sql/sql_parse.cc:1857

    #9 0x55bebf6638b0 in do_command(THD*) /data/src/10.4/sql/sql_parse.cc:1378

    #10 0x55bebfa62e0f in do_handle_one_connection(CONNECT*) /data/src/10.4/sql/sql_connect.cc:1420

    #11 0x55bebfa62726 in handle_one_connection /data/src/10.4/sql/sql_connect.cc:1324

    #12 0x55bec06d2e1f in pfs_spawn_thread /data/src/10.4/storage/perfschema/pfs.cc:1869

    #13 0x7fc5276a7fd3 in start_thread nptl/pthread_create.c:442

Thread T5 created by T0 here:

    #0 0x7fc527c49726 in __interceptor_pthread_create ../../../../src/libsanitizer/asan/asan_interceptors.cpp:207

    #1 0x55bec06d320c in spawn_thread_v1 /data/src/10.4/storage/perfschema/pfs.cc:1919

    #2 0x55bebf36ef89 in inline_mysql_thread_create /data/src/10.4/include/mysql/psi/mysql_thread.h:1275

    #3 0x55bebf386690 in create_thread_to_handle_connection(CONNECT*) /data/src/10.4/sql/mysqld.cc:6287

    #4 0x55bebf386ddb in create_new_thread(CONNECT*) /data/src/10.4/sql/mysqld.cc:6357

    #5 0x55bebf3872a9 in handle_accepted_socket(st_mysql_socket, st_mysql_socket) /data/src/10.4/sql/mysqld.cc:6455

    #6 0x55bebf388155 in handle_connections_sockets() /data/src/10.4/sql/mysqld.cc:6613

    #7 0x55bebf385df3 in mysqld_main(int, char**) /data/src/10.4/sql/mysqld.cc:5945

    #8 0x55bebf36d0b8 in main /data/src/10.4/sql/main.cc:25

    #9 0x7fc527646189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

SUMMARY: AddressSanitizer: use-after-poison ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 in __interceptor_memcpy

Shadow bytes around the buggy address:

  0x0c428001ad60: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

  0x0c428001ad70: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

  0x0c428001ad80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

  0x0c428001ad90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

  0x0c428001ada0: 00 00 00 00 f7 00 00 00 00 f7 04 f7 00 00 00 00

=>0x0c428001adb0:[02]f7 00 00 00 00 02 f7 00 00 00 00 00 00 00 00

  0x0c428001adc0: 00 00 00 00 00 00 00 f7 00 f7 00 00 00 00 00 00

  0x0c428001add0: 00 00 00 00 00 00 00 f7 00 f7 f7 f7 f7 f7 f7 f7

  0x0c428001ade0: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7

  0x0c428001adf0: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7

  0x0c428001ae00: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7

Shadow byte legend (one shadow byte represents 8 application bytes):

  Addressable:           00

  Partially addressable: 01 02 03 04 05 06 07 

  Heap left redzone:       fa

  Freed heap region:       fd

  Stack left redzone:      f1

  Stack mid redzone:       f2

  Stack right redzone:     f3

  Stack after return:      f5

  Stack use after scope:   f8

  Global redzone:          f9

  Global init order:       f6

  Poisoned by user:        f7

  Container overflow:      fc

  Array cookie:            ac

  Intra object redzone:    bb

  ASan internal:           fe

  Left alloca redzone:     ca

  Right alloca redzone:    cb

==3640855==ABORTING