Incompatible Change: In binary installations of MySQL, the supplied binary-configure script would start and configure MySQL, even when command help was requested with the --help command-line option. The --help option, if provided, no longer starts and installs the server. (Bug #30954)

Replication: BEGIN statements were not included in the output of mysqlbinlog. (Bug #46998)

Replication: Database-level character sets were not always honored by the replication SQL thread. This could cause data inserted on the master using LOAD DATA to be replicated using the wrong character set. (Bug #45516)

API: The fix for Bug #24507 could lead in some cases to client application failures due to a race condition. Now the server waits for the “dummy” thread to return before exiting, thus making sure that only one thread can initialize the POSIX threads library. (Bug #42850)

When re-installing MySQL on Windows on a server that has a data directory from a previous MySQL installation, the installer would fail to identify the existence of the installation and the password configured for the root user. (Bug #45200)

When creating a new instance on Windows using mysqld-nt and the --install parameter, the value of the service would be set incorrectly, resulting in a failure to start the configured service. (Bug #46917)

Concurrent execution of FLUSH TABLES along with SHOW FUNCTION STATUS or SHOW PROCEDURE STATUS could cause a server crash. (Bug #34895)

A test for stack growth failed on some platforms, leading to server crashes. (Bug #42213)

References: See also Bug #62856.

The server ignored the setting of sync_frm for CREATE TABLE ... LIKE. (Bug #46591)

CONCAT_WS() could return incorrect results due to an argument buffer also being used as a result buffer. (Bug #46815)

myisamchk performed parameter value casting at startup that generated unnecessary warning messages. (Bug #33785)

The server crashed when re-using outer column references in correlated subqueries when the enclosing query used a temp table. (Bug #46791)

An attempt to create a table with the same name as an existing view could cause a server crash. (Bug #46384)

Client flags were incorrectly initialized for the embedded server, causing several tests in the jp test suite to fail. (Bug #45159)

A memory leak occurred when EXPLAIN encountered a malformed query. (Bug #45989)

EXPLAIN caused a server crash for certain valid queries. (Bug #47106)

Solaris binary packages now are compiled with -g0 rather than -g. (Bug #47137)

On Mac OS X or Windows, sending a SIGHUP signal to the server or an asynchronous flush (triggered by flush_time) caused the server to crash. (Bug #47525)

The server used the wrong lock type (always TL_READ instead of TL_READ_NO_INSERT when appropriate) for tables used in subqueries of UPDATE statements. This led in some cases to replication failure because statements were written in the wrong order to the binary log. (Bug #42108)

Changing the size of a key buffer that is under heavy use could cause a server crash. The fix partially removes the limitation that LOAD INDEX INTO CACHE fails unless all indexes in a table have the same block size. Now the statement fails only if IGNORE LEAVES is specified. (Bug #17332)

When building MySQL on Windows from source, the WITH_BERKELEY_STORAGE_ENGINE option would fail to configure BDB support correctly. (Bug #27693)