Comment 30 for bug 1417810

I was to reproduce this reliably. Here's how:

CREATE TABLE `wp_options` (
  `option_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `option_name` varchar(64) 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`)
) ENGINE=InnoDB CHARSET=utf8;

INSERT INTO wp_options SET option_id=1, option_value='x';

UPDATE wp_options SET option_value=REPEAT('x', 19000000) WHERE option_id=1;

ERROR 2013 (HY000): Lost connection to MySQL server during query

I'm going to try different mysqld / linux kernel combinations and will report my findings soon.