[#MDEV-27390] InnoDB: Corruption of an index tree

Recently we had mariadb (10.4.22) crash in a loop. The cause seems to be an index corruption. We exported the binlogs for this specific DB, and were able to consistently reproduce (tho cannot share the binlogs because of sensitive data) but were unable to produce a small test case.

MariaDB [test]> select option_id,hex(option_name) from wp_options where option_id in(19269,74606) order by option_name asc\G

*************************** 1. row ***************************

       option_id: 19269

hex(option_name): 77705F696E7374616C6C65725F73657474696E6773

*************************** 2. row ***************************

       option_id: 74606

hex(option_name): 77705F696E7374616C6C65725F73657474696E6773

2 rows in set (0.000 sec)

MariaDB [test]> show create table wp_options\G

*************************** 1. row ***************************

       Table: wp_options

Create Table: CREATE TABLE `wp_options` (

  `option_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,

  `option_name` varchar(191) NOT NULL DEFAULT '',

  `option_value` longtext NOT NULL,

  `autoload` varchar(20) NOT NULL DEFAULT 'yes',

  PRIMARY KEY (`option_id`),

  UNIQUE KEY `option_name` (`option_name`),

  KEY `autoload` (`autoload`)

) ENGINE=InnoDB AUTO_INCREMENT=74609 DEFAULT CHARSET=utf8mb4

1 row in set (0.000 sec)

Replaying the same binlogs on 10.3.32 or 10.4.18 doesn't corrupt the index. Instead, it stops with a duplicate entry error:

[MDEV-27390] InnoDB: Corruption of an index tree Created: 2021-12-30 Updated: 2021-12-30
Status:	Open
Project:	MariaDB Server
Component/s:	Server
Affects Version/s:	10.4.19, 10.4.20, 10.4.21, 10.4.22, 10.5.13, 10.6.5
Fix Version/s:	None

[MDEV-27390] InnoDB: Corruption of an index tree Created: 2021-12-30 Updated: 2021-12-30