MyRocks crashes when TTL is defined on table with composite PK with varchar column in utf8_bin or latin_bin and query uses index on another column

CREATE TABLE `test` (

  `a` bigint(20) NOT NULL,
  `b` varchar(10) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `u` bigint(20) unsigned NOT NULL,
  `d` bigint(20) DEFAULT NULL,
  PRIMARY KEY (`a`,`b`),
  KEY `d` (`d`)
) ENGINE=ROCKSDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='ttl_duration=1000;ttl_col=u';

mysql> insert into test values (100, 'aaabbb', unix_timestamp(), 200);

mysql> explain select count(*) from test;
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
| id | select_type | table | partitions | type  | possible_keys | key  | key_len | ref  | rows | filtered | Extra       |
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
|  1 | SIMPLE      | test  | NULL       | index | NULL          | d    | 9       | NULL |    0 |     0.00 | Using index |
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
1 row in set, 1 warning (0.00 sec)

mysql> select count(*) from test;
ERROR 2013 (HY000): Lost connection to MySQL server during query

17:38:39 UTC - mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
Attempting to collect some information that could help diagnose the problem.
As this is a crash and something is definitely wrong, the information
collection process might fail.
Please help us make Percona Server better by reporting any
bugs at http://bugs.percona.com/
 
key_buffer_size=134217728
read_buffer_size=6291456
max_used_connections=2
max_threads=2049
thread_count=3
connection_count=1
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 23228750 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.
 
Thread pointer: 0x2ad4c80d7000
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 2ad4265cacf0 thread_stack 0x40000
/usr/sbin/mysqld(my_print_stacktrace+0x3b)[0xf0077b]
/usr/sbin/mysqld(handle_fatal_signal+0x471)[0x7a5161]
/lib64/libpthread.so.0(+0xf5e0)[0x2ad42689e5e0]
/usr/lib64/mysql/plugin/ha_rocksdb.so(_ZNK7myrocks11Rdb_key_def39unpack_binary_or_utf8_varchar_space_padEPNS_17Rdb_field_packingEP5FieldPhPNS_17Rdb_string_readerES7_+0x43)[0x2ad4976c8f93]
/usr/lib64/mysql/plugin/ha_rocksdb.so(_ZNK7myrocks11Rdb_key_def13unpack_recordEP5TABLEPhPKN7rocksdb5SliceES7_RKb+0x212)[0x2ad4976ccba2]
/usr/lib64/mysql/plugin/ha_rocksdb.so(_ZN7myrocks10ha_rocksdb20secondary_index_readEiPh+0x289)[0x2ad4976a45e9]
/usr/lib64/mysql/plugin/ha_rocksdb.so(_ZN7myrocks10ha_rocksdb25index_next_with_directionEPhb+0xa9)[0x2ad4976a60b9]
/usr/lib64/mysql/plugin/ha_rocksdb.so(_ZN7myrocks10ha_rocksdb18index_first_internEPh+0x133)[0x2ad4976a6303]
/usr/lib64/mysql/plugin/ha_rocksdb.so(_ZN7myrocks10ha_rocksdb11index_firstEPh+0x65)[0x2ad4976a6565]
/usr/sbin/mysqld(_ZN7handler14ha_index_firstEPh+0x11f)[0x8104bf]
/usr/sbin/mysqld(_Z15join_read_firstP7QEP_TAB+0x82)[0xc9afc2]
/usr/sbin/mysqld(_Z10sub_selectP4JOINP7QEP_TABb+0x11b)[0xca177b]
/usr/sbin/mysqld(_ZN4JOIN4execEv+0x267)[0xc9a4a7]
/usr/sbin/mysqld(_Z12handle_queryP3THDP3LEXP12Query_resultyy+0x17d)[0xd0b93d]
/usr/sbin/mysqld[0x7625d8]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THDb+0x44e1)[0xccd191]
/usr/sbin/mysqld(_Z11mysql_parseP3THDP12Parser_state+0x5e5)[0xcd06f5]
/usr/sbin/mysqld(_Z16dispatch_commandP3THDPK8COM_DATA19enum_server_command+0xabd)[0xcd12bd]
/usr/sbin/mysqld(_Z10do_commandP3THD+0x1df)[0xcd2cff]
/usr/sbin/mysqld(handle_connection+0x2b8)[0xd9c8f8]
/usr/sbin/mysqld(pfs_spawn_thread+0x1b4)[0xf18904]
/lib64/libpthread.so.0(+0x7e25)[0x2ad426896e25]
/lib64/libc.so.6(clone+0x6d)[0x2ad4286fd34d]
 
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (2ad4c800e030): select count(*) from test
Connection ID (thread ID): 8
Status: NOT_KILLED

mysql> select count(*) from test use index(primary);
+----------+
| count(*) |
+----------+
|        1 |
+----------+
1 row in set (0.00 sec) 

mysql> CREATE TABLE `test2` (
  `a` bigint(20) NOT NULL,
  `b` bigint(20) NOT NULL,
  `u` bigint(20) unsigned NOT NULL,
  `d` bigint(20) DEFAULT NULL,
  PRIMARY KEY (`a`,`b`),
  KEY `d` (`d`)
) ENGINE=ROCKSDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='ttl_duration=1000;ttl_col=u';

mysql> insert into test2 values (100, 200, unix_timestamp(), 200);

mysql> explain select count(*) from test;
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
| id | select_type | table | partitions | type  | possible_keys | key  | key_len | ref  | rows | filtered | Extra       |
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
|  1 | SIMPLE      | test  | NULL       | index | NULL          | d    | 9       | NULL |    0 |     0.00 | Using index |
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
1 row in set, 1 warning (0.00 sec)

mysql> select count(*) from test2;
+----------+
| count(*) |
+----------+
|        1 |
+----------+
1 row in set (0.01 sec)

mysql> CREATE TABLE `test3` (
  `a` bigint(20) NOT NULL,
  `b` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
  `u` bigint(20) unsigned NOT NULL,
  `d` bigint(20) DEFAULT NULL,
  PRIMARY KEY (`a`,`b`),
  KEY `d` (`d`)
) ENGINE=ROCKSDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin COMMENT='ttl_duration=1000;ttl_col=u';

mysql> insert into test3 values (100, 'aaabbb', unix_timestamp(), 200);

mysql> explain select count(*) from test3;
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
| id | select_type | table | partitions | type  | possible_keys | key  | key_len | ref  | rows | filtered | Extra       |
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
|  1 | SIMPLE      | test3 | NULL       | index | NULL          | d    | 9       | NULL |    0 |     0.00 | Using index |
+----+-------------+-------+------------+-------+---------------+------+---------+------+------+----------+-------------+
1 row in set, 1 warning (0.00 sec)

mysql> select count(*) from test3;
+----------+
| count(*) |
+----------+
|        1 |
+----------+
1 row in set (0.00 sec)