Wrap BEGIN/COMMIT around transaction in the binary log. This makes replication honor transactions.
Fixed security bug when having an empty database name in the user.db table.
Changed initialization of RND() to make it less predicatable.
Fixed problem with GROUP BY on result with expression that created a BLOB field.
Fixed problem with GROUP BY on columns that have NULL values. To solve this we now create an MyISAM temporary table when doing a GROUP BY on a possible NULL item. From MySQL 4.0.5 we can use in memory HEAP tables for this case.
Fixed problem with privilege tables when downgrading from 4.0.2 to 3.23.
Fixed thread bug in SLAVE START, SLAVE STOP and automatic repair of MyISAM tables that could cause table cache to be corrupted.
Fixed possible thread related key-cache-corruption problem with OPTIMIZE TABLE and REPAIR TABLE.
Added name of 'administrator command' logs.
Fixed bug with creating an auto-increment value on second part of a UNIQUE() key where first part could contain NULL values.
Don't write slave-timeout reconnects to the error log.
Fixed bug with slave net read timeouting
Fixed a core-dump bug with MERGE tables and MAX() function.
Fixed bug in ALTER TABLE with BDB tables.
Fixed bug when logging LOAD DATA INFILE to binary log with no active database.
Fixed a bug in range optimizer (causing crashes).
Fixed possible problem in replication when doing DROP DATABASE on a database with InnoDB tables.
Fixed mysql_info() to return 0 for Duplicates value when using INSERT DELAYED IGNORE.
Added -DHAVE_BROKEN_REALPATH to the Mac OS X (darwin) compile options in configure.in to fix a failure under high load.