The recently added test innodb.innodb_wl6326 hangs in 10.4, because a query
causes ha_innobase::records_in_range() to be called with min_key=NULL. No secondary indexes have been defined on the table; only PRIMARY KEY(a00,a01,a02,a03,a04,a05,a06).
That section of the test is demonstrating that only some pages of the table are supposed to be latched.
The hang is caused by ‘too broad’ ha_innobase::records_in_range() calls. Those calls were introduced by an early commit of
MDEV-16188. With the parent of that commit, the following test will not hang:
I would expect the too broad ha_innobase::records_in_range() calls to cause a performance regression, especially if they are being invoked for each and every query. InnoDB will not cache the results of that call in any way.