Check TABLE .. EXTENDED returns Warning InnoDB: The B-tree of index ... is corrupted

The server error log shows

[rr 1127005 47893]2021-03-11  2:42:46 15 [Note] InnoDB: Record in index `PRIMARY` of table `test`.`t1`, page [page id: space=6, page number=33], at offset 10656

[rr 1127005 47897]2021-03-11  2:42:46 15 [ERROR] InnoDB: Field 7 len is 499, should be 4; COMPACT RECORD(info_bits=0, 8 fields): {[4]   l(0x8000006C),[6]     %(0x000000000025),[7]    ?  (0x8C0000013F02CC),[4]   l(0x8000006C),NULL,[0+20](0x)(0x0000000000000000000000000000000000000000),[4]   l(0x8000006C),[499]1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111(0x31313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131313131

follwed by the SIGKILL sent by RQG because one connection had harvested a 

Warning InnoDB: The B-tree of index PRIMARY is corrupted

for a CHECK TABLE t1 EXTENDED.

sdp:/home/mleich/RQG_O/storage/1615459353/TBR-757/dev/shm/vardir/1615459353/1/1/rr

_RR_TRACE_DIR="." rr replay --mark-stdio

RQG

===

git clone https://github.com/mleich1/rqg --branch experimental RQG

perl rqg.pl \

--duration=300 \

--queries=10000000 \

--no_mask \

--seed=random \

--gendata=conf/mariadb/table_stress.zz \

--gendata_sql=conf/mariadb/table_stress.sql \

--rpl_mode=none \

--engine=InnoDB \

--mysqld=--log-output=none \

--mysqld=--net_write_timeout=60 \

--mysqld=--innodb-buffer-pool-size=64M \

--mysqld=--loose-debug_assert_on_not_freed_memory=0 \

--mysqld=--loose-idle_write_transaction_timeout=0 \

--mysqld=--wait_timeout=28800 \

--mysqld=--innodb-lock-wait-timeout=50 \

--mysqld=--net_read_timeout=30 \

--mysqld=--lock-wait-timeout=86400 \

--mysqld=--loose_innodb_lock_schedule_algorithm=fcfs \

--mysqld=--interactive_timeout=28800 \

--mysqld=--file-key-management-filename=$RQG_HOME/conf/mariadb/encryption_keys.txt \

--mysqld=--connect_timeout=60 \

--mysqld=--loose-max-statement-time=30 \

--mysqld=--slave_net_timeout=60 \

--mysqld=--plugin-load-add=file_key_management.so \

--mysqld=--loose-idle_readonly_transaction_timeout=0 \

--mysqld=--log_bin_trust_function_creators=1 \

--mysqld=--log-bin \

--mysqld=--loose-idle_transaction_timeout=0 \

--mysqld=--loose-table_lock_wait_timeout=50 \

--reporters=Backtrace,Deadlock1,ErrorLog \

--validators=None \

--grammar=TBR-757.yy \

--threads=3 \

--workdir=<local settings> \

--vardir=<local settings> \

--mtr-build-thread=<local settings> \

--basedir1=<local settings> \

--script_debug=_nix_ \

--rr=Server \

--rr_options=--chaos

The simplified RQG grammar contains

fill_end:

    AS CHAR),1,1), @fill_amount) ;

my_int:

    { $my_int= $prng->int( 65, 512) } ;

string_fill:

    REPEAT(SUBSTR(CAST( $my_int AS CHAR),1,1), 10) ;

thread1:

    CHECK TABLE t1 EXTENDED ;

thread1_connect:

    ;

thread1_init:

    CREATE TABLE t1 ( col1 INT PRIMARY KEY, col_int INTEGER , col_string INTEGER , col_text TEXT , col_int_g INTEGER GENERATED ALWAYS AS (col_int) PERSISTENT , col_text_g TEXT GENERATED ALWAYS AS (SUBSTR(col_text,1,499)) PERSISTENT ) ENGINE = InnoDB ROW_FORMAT = Dynamic ;

thread2:

    INSERT INTO t1 (col1, col_int, col_text) VALUES ( my_int , $my_int, REPEAT(SUBSTR(CAST( $my_int fill_end ) ;

thread2_connect:

    SET AUTOCOMMIT = 0; SET @fill_amount = (@@innodb_page_size / 2 ) + 1 ;

thread2_init:

    ;

No failure on check table in case of

- PERSISTENT replaced with VIRTUAL

- 10.5.9 or older 10.6 used

- InnoDB replaced with ARIA