mysqldump --single-transaction now uses START TRANSACTION /*!40100 WITH CONSISTENT SNAPSHOT */ rather than BEGIN to start a transaction, so that a consistent snapshot will be used on those servers that support it. (Bug#19660)

Through the C API, the member strings in MYSQL_FIELD for a query that contains expressions may return incorrect results. (Bug#21635)

IN() can return NULL, but did not signal that to the query processor, causing incorrect results for IS NULL operations. (Bug#17047)

The server could send incorrect column count information to the client for queries that produce a larger number of columns than can fit in a two-byte number. (Bug#19216)

SQL statements close to the size of max_allowed_packet could produce binary log events larger than max_allowed_packet that could not be read by slave servers. (Bug#19402)

If elements in a non-top-level IN subquery were accessed by an index and the subquery result set included a NULL value, the quantified predicate that contained the subquery was evaluated to NULL when it should return a non-NULL value. (Bug#23478)

Metadata for columns calculated from scalar subqueries was limited to integer, double, or string, even if the actual type of the column was different. (Bug#11032)

For ODBC compatibility, MySQL supports use of WHERE col_name IS NULL for DATE or DATETIME columns that are NOT NULL, to allow column values of '0000-00-00' or '0000-00-00 00:00:00' to be selected. However, this was not working for WHERE clauses in DELETE statements. (Bug#23412)

mysql did not check for errors when fetching data during result set printing. (Bug#22913)

Adding a day, month, or year interval to a DATE value produced a DATE, but adding a week interval produced a DATETIME value. Now all produce a DATE value. (Bug#21811)

For not-yet-authenticated connections, the Time column in SHOW PROCESSLIST was a random value rather than NULL. (Bug#23379)

The Handler_rollback status variable sometimes was incremented when no rollback had taken place. (Bug#22728)

Lack of validation for input and output TIME values resulted in several problems: SEC_TO_TIME() within subqueries incorrectly clipped large values; SEC_TO_TIME() treated BIGINT UNSIGNED values as signed; only truncation warnings were produced when both truncation and out-of-range TIME values occurred. (Bug#11655, Bug#20927)

Range searches on columns with an index prefix could miss records. (Bug#20732)

Transient errors in replication from master to slave may trigger multiple Got fatal error 1236: 'binlog truncated in the middle of event' errors on the slave. (Bug#4053)

If COMPRESS() returned NULL, subsequent invocations of COMPRESS() within a result set or within a trigger also returned NULL. (Bug#23254)

mysql would lose its connection to the server if its standard output was not writable. (Bug#17583)

mysql-test-run did not work correctly for RPM-based installations. (Bug#17194)

The return value from my_seek() was ignored. (Bug#22828)

MySQL would fail to build on the Alpha platform. (Bug#23256)