The following changes between MySQL 5.6.43 and MySQL 5.6.44 touch InnoDB files.
Bug#28104394 : INNODB 5.7 PRIMARY KEY SCAN LACK DATA
This is one more fix for the "optimized range scan" series of regressions caused by a change that we decided not to merge to MariaDB in
Bug #25289359 DML/DDL ON LARGE FULLTEXT TABLES CAUSE SEMAPHORE TIMEOUTS AND ASSERTION/SUICIDE
There is no test case, but there is debug instrumentation. We will investigate the scenario and track this change in MDEV-20126.