MySQL 5.5.39 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:
This release, similar to the last 5.5 release, is mostly uneventful.
There were two “Functionality Added or Changed” and 24 bugs fixed.
The “Functionality Added or Changed” changes are:
- CMake support was updated to handle CMake version 3.
- The timed_mutexes system variable has no effect and is deprecated.
Out of the 24 bugs, most seemed rather minor or obscure, but here are the ones I think are worth noting (crashing, security, wrong results, deadlock):
- InnoDB: Opening a parent table that has thousands of child tables could result in a long semaphore wait condition.
- Partitioning: Selecting from a table having multiple columns in its primary key and partitioned by LIST COLUMNS(R), where R was the last (rightmost) column listed in the primary key definition, returned an incorrect result. (Bug #71095)
- Replication: When using row-based replication, updating or deleting a row on the master that did not exist on the slave led to failure of the slave when it tried to process the change. This problem occurred with InnoDB tables lacking a primary key. (Bug #72085)
- Replication: A group of threads involved in acquiring locks could deadlock in a certain scenario. (Bug #69954)
- ALTER TABLE on a partitioned table could result in the wrong storage engine being written into the table’s .frm file and displayed in SHOW CREATE TABLE.
- MyISAM temporary files could be used to mount a code-execution attack.
- An assertion could be raised when creating a index on a prefix of a TINYBLOB or GEOMETRY column in an InnoDB column.
- Deadlock could occur if three threads simultaneously performed INSTALL PLUGIN, SHOW VARIABLES, and mysql_change_user(). (Bug #71236, Bug #72870)
- MySQL did not compile with Bison 3. A workaround is to downgrade to Bison 2. (Bug #71250)
For reference, the full 5.5.39 changelog can be viewed here:
Hope this helps.