InnoDB: A tablespace import operation that failed due to the source and destination tables being defined with different DATA DIRECTORY clauses reported an insufficiently descriptive schema mismatch error. Moreover, if a .cfg file was not present, the same operation would raise an assertion failure. A more informative error message is now reported in both cases before the import operation is terminated due to the data directory mismatch. (Bug #30190199, Bug #30190227, Bug #20644698, Bug #76142)

InnoDB: Updating certain InnoDB system variables that take string values raised invalid read errors during Valgrind testing. (Bug #29717909, Bug #95215)

Replication: In the event of an unplanned disconnection of a replication slave from the master, the reference to the master's dump thread might not be removed from the list of registered slaves, in which case statements that accessed the list of slaves would fail. The issue has now been fixed. (Bug #29915479)

Replication: With the settings binlog_format=MIXED, tx_isolation=READ-COMMITTED, and binlog_row_image=FULL, an INSERT ... SELECT query involving a transactional storage engine omitted any columns with a null value from the row image written to the binary log. This happened because when processing INSERT ... SELECT statements, the columns were marked for inserts before the binary logging format was selected. The issue has now been fixed. (Bug #29110804, Bug #93423)

The Event Scheduler had a memory leak. (Bug #30628268)

Under certain circumstances, a memcached command could result in reading an uninitialized memory buffer, causing a failure. (Bug #30592346)

CONCAT() and CONCAT_WS() could produce incorrect results in rare cases due to incorrect substring handling. (Bug #30350206, Bug #96950)

Scheduling of events could be disturbed by removing events. (Bug #30301356, Bug #96849)

Client programs could load authentication plugins from outside the plugin library. (Bug #30191834, Bug #30644258)

A query with a WHERE clause whose predicate contained a numeric value in scientific notation was not handled correctly.

In addition, attempting to insert a particular integer specified as a string caused a server exit when the string-to-integer conversion was not successful. (Bug #29723340, Bug #30441969)

The client library could dereference a null pointer while fetching result set metadata from the server. (Bug #29597896, Bug #30689251)