Fixed MysqlValidConnectionChecker for JBoss doesn't work with MySQLXADataSources. (Bug #20242)

Better caching of character set converters (per-connection) to remove a bottleneck for multibyte character sets. (Bug #20242)

Added connection/datasource property pinGlobalTxToPhysicalConnection (defaults to false). When set to true, when using XAConnections, the driver ensures that operations on a given XID are always routed to the same physical connection. This enables the XAConnection to support XA START ... JOIN after XA END has been called, and is also a workaround for transaction managers that don't maintain thread affinity for a global transaction (most either always maintain thread affinity, or have it as a configuration option). (Bug #20242)

MysqlXaConnection.recover(int flags) now permits combinations of XAResource.TMSTARTRSCAN and TMENDRSCAN. To simulate the “scanning” nature of the interface, we return all prepared XIDs for TMSTARTRSCAN, and no new XIDs for calls with TMNOFLAGS, or TMENDRSCAN when not in combination with TMSTARTRSCAN. This change was made for API compliance, as well as integration with IBM WebSphere's transaction manager. (Bug #20242)

Fixed ConnectionProperties (and thus some subclasses) are not serializable, even though some J2EE containers expect them to be. (Bug #19169)

Fixed driver fails on non-ASCII platforms. The driver was assuming that the platform character set would be a superset of the MySQL latin1 character set when doing the handshake for authentication, and when reading error messages. We now use Cp1252 for all strings sent to the server during the handshake phase, and a hard-coded mapping of the language system variable to the character set that is used for error messages. (Bug #18086)

Fixed can't use XAConnection for local transactions when no global transaction is in progress. (Bug #17401)