Performance: The InnoDB adaptive hash latch is released (if held) for several potentially long-running operations. This improves throughput for other queries if the current query is removing a temporary table, changing a temporary table from memory to disk, using CREATE TABLE ... SELECT, or performing a MyISAM repair on a table used within a transaction. (Bug#32149)

Security Fix: A suitable database identifier supplied to the COM_CREATE_DB or COM_DROP_DB command could cause a segmentation fault, and thereby a denial of service. (Bug#45790, CVE-2009-2446)

Security Fix: The server crashed if an account with the CREATE ROUTINE privilege but not the EXECUTE privilege attempted to create a stored procedure. (Bug#44798)

Important Change: Replication: BEGIN, COMMIT, and ROLLBACK statements are no longer affected by --replicate-do-db or --replicate-ignore-db rules. (Bug#43263)

Replication: When reading a binary log that was in use by a master or that had not been properly closed (possibly due to a crash), the following message was printed: Warning: this binlog was not closed properly. Most probably mysqld crashed writing it. This message did not take into account the possibility that the file was merely in use by the master, which caused some users concern who were not aware that this could happen.

To make this clear, the original message has been replaced with Warning: this binlog is either is use or was not closed properly. (Bug#34687)

The server crashed for attempts to use REPLACE or INSERT ... ON DUPLICATE KEY UPDATE with a view defined using a join. (Bug#45806)

The combination of MIN() or MAX() in the select list with WHERE and GROUP BY clauses could lead to incorrect results. (Bug#45386)

Compiler warnings on Mac OS X were fixed. (Bug#45286)

The mysql client could misinterpret some character sequences as commands under some circumstances. (Bug#45236)

Use of ROUND() on a LONGTEXT or LONGBLOB column of a derived table could cause a server crash. (Bug#45152)

Index Merge followed by a filesort could result in a server crash if sort_buffer_size was not large enough for all sort keys. (Bug#44810)

See also Bug#40974.

The PASSWORD() and OLD_PASSWORD() functions could read memory outside of an internal buffer when used with BLOB arguments. (Bug#44767)

Some Perl scripts in AIX packages contained an incorrect path to the perl executable. (Bug#44643)

A workaround for a Sun Studio bug was instituted. (Bug#41710)

Shared-memory connections did not work in Vista if mysqld was started from the command line. (Bug#41190)

Some UPDATE statements that affected no rows returned a rows-affected count of one. (Bug#40565)

Valgrind warnings that occurred for SHOW TABLE STATUS with InnoDB tables were silenced. (Bug#38479)

In the mysql client, using a default character set of binary caused internal commands such as DELIMITER to become case sensitive. (Bug#37268)

A Valgrind error during subquery execution was corrected. (Bug#36995)

When invoked to start multiple server instances, mysqld_multi sometimes would fail to start them all due to not changing location into the base directory for each instance. (Bug#36654)

On Windows, the _PC macro in my_global.h was causing problems for modern compilers. It has been removed because it is no longer used. (Bug#34309)

Setting the session value of the max_allowed_packet or net_buffer_length system variable was allowed but had no effect. The session value of these variables is now read only. (Bug#32223)

See also Bug#22891.