MySQL Connector/C 6.1.5 has been released

[Jocelyn Ramilison]

Dear MySQL users,

MySQL Connector/C 6.1.5, a new version of the C API for client/server
communication for the MySQL database management system, has been
released.

This version of Connector/C provides full support for MySQL 5.6
protocol. Connector/C is compatible with the client libraries
(libmysql). It includes all the features in the MySQL client library
shipped with MySQL servers 5.6 as well as prior versions. You can
recompile existing code linked with Connector/C 6.1.5 without any code
changes.

You can use Connector/C to run and build client applications which
communicate with MySQL server versions from 5.5 to 5.6 without a need
to do a complete server installation.

The release is now available in source and binary form for a number
of platforms from our download pages at

  http://dev.mysql.com/downloads/connector/c/

MySQL Connector/C 6.1.5 will also be available for downloads via the
Oracle Software Delivery Cloud in approximately 1-2 weeks.

For information on installing, please see the documentation at

http://dev.mysql.com/doc/connector-c/en/connector-c-installation.html

Enjoy!

Changes in MySQL Connector/C 6.1.5 (2014-06-17)

Connector/C 6.1.5 upgrades the linked OpenSSL library from version
1.0.1g to version 1.0.1h. Versions of OpenSSL prior to 1.0.1g are
reported vulnerable to CVE-2014-0224.

Functionality Added or Changed

  * The server can now report session-state changes to client
    programs. Reportable session state consists of these values:

       + The default schema (database)

       + Session-specific values for system variables

       + User-defined variables

       + Temporary tables

       + Prepared statements
    The MySQL client/server protocol now includes tracker
    information so that session state changes can be detected. One
    use for the tracker mechanism is that it provides a means for
    MySQL Connectors, Fabric, and client applications to determine
    whether any session context is available to ensure session
    migration from one server to another. (To change connections
    in a load-balanced environment, it is necessary to detect
    whether there is session state to take into consideration when
    deciding whether a switch can be made.)
    The user interface to control the tracker and retrieve
    state-change information from it has the following components,
    which enable implementation of state-change tracking on the
    client side:

       + Clients can request notification when there is a change
         to any of the session state-related values just listed,
         in the form of a flag that is set in the OK packet
         received from the server after the change occurs. To
         control notification, enable or disable the
         session_track_state_change system variable. This variable
         is disabled by default.

       + Clients can request notification of changed values for
         certain specific types of session state information:
            o The default schema name. To control notification,
              enable or disable the session_track_schema system
              variable. This variable is enabled by default.
            o The session values of system variables. Notification
              occurs for the system variables named by the
              session_track_system_variables system variable. By
              default, notification is enabled for time_zone,
              autocommit, character_set_client,
              character_set_results, and character_set_connection.
              (The latter three variables are those affected by
              SET NAMES.)

       + To enable applications to extract the state-change
         information returned by the server, the MySQL C API
         includes a pair of functions:
            o mysql_session_track_get_first() fetches the first
              state-change information received from the server.
            o mysql_session_track_get_next() fetches any remaining
              state-change information received from the server.
              Following a successful call to
              mysql_session_track_get_first(), call this function
              repeatedly as long as it returns success.

       + The mysqltest program has enable_session_track_info and
         disable_session_track_info commands to enable and disable
         tracking of session state-change information.
    For more information, see Server System Variables
    (http://dev.mysql.com/doc/refman/5.6/en/server-system-variable
    s.html) and mysql_session_track_get_first()
    (http://dev.mysql.com/doc/refman/5.7/en/mysql-session-track-ge
    t-first.html). For information about the structure of the OK
    packet used to convey state-change information, see OK_Packet
    (http://dev.mysql.com/doc/internals/en/packet-OK_Packet.html).

  * Because there are new API functions
    (mysql_session_track_get_first(),
    mysql_session_track_get_next()), the client library ABI
    version is now 18.3. Shared library names now include 18.3
    where appropriate.

Bugs Fixed

  * Calling mysql_get_server_version() with an invalid connection
    handler argument caused the client to exit. Now it returns 0
    and reports a CR_COMMANDS_OUT_OF_SYNC error. (Bug #18053212)

  * The C client library could leak memory when client plugins
    were used. (Bug #17933308)

  * On Windows, calling mysql_thread_init() call without
    mysql_init() caused the client to exit. Now it returns a
    nonzero result because it is an error to call
    mysql_thread_init() before the client library is initialized
    with mysql_library_init(). (Bug #17514920)

  * There was a difference in certificate handling by yaSSL and
    OpenSSL (used for Community and Enterprise, respectively).
    OpenSSL expected a blank certificate to be sent when not all
    of the --ssl-ca, --ssl-cert, and --ssl-key options were
    specified, and yaSSL did not do so. To resolve this, yaSSL has
    been modified to send a blank certificate when an option is
    missing. (Bug #68788, Bug #16715064)

-- 

Hery Ramilison
MySQL/ORACLE Release Engineering Team