* CMake configuration support on Linux now provides a boolean ENABLE_GCOV
option to control whether to include support for gcov.
* InnoDB now permits concurrent reads while creating a secondary index.
* Client programs now display more information for SSL errors to aid in
diagnosis and debugging of connection problems.
* In the audit plugin interface, the event_class member was removed from the
mysql_event_general structure and the calling sequence for the notification
function changed. Originally, the second argument was a pointer to the event
structure. The function now receives this information as two arguments: an
event class number and a pointer to the event. Corresponding to these
changes, MYSQL_AUDIT_INTERFACE_VERSION was increased to 0x0300.
* The plugin_audit.h header file, and the NULL_AUDIT example plugin in the
plugin/audit_null directory have been modified per these changes. See
Section 21.2.4.7, “Writing Audit Plugins”.
* Bug fixes.