Log Message:
Changes 5.6.31:

Security Notes

The linked OpenSSL library for the MySQL Commercial Server has been updated to \ 
version 1.0.1t. Issues fixed in the new version are described at \ 
http://www.openssl.org/news/vulnerabilities.html.

This change does not affect the Oracle-produced MySQL Community build of MySQL \ 
Server, which uses the yaSSL library instead. (Bug 23229564)

Functionality Added or Changed

A new CMake option, WITH_SYMVER16, if enabled, causes the libmysqlclient client \ 
library to contain extra symbols to be compatible with libmysqlclient on \ 
RHEL/OEL 5, 6, 7, and Fedora releases. All symbols present in \ 
libmysqlclient.so.16 are tagged with symver 16 in libmsqlclient.so.18, making \ 
those symbols have both symver 16 and 18. (Bug 22980983)

support-files/MacOSX/ReadMe.txt is no longer included in MySQL distributions. \ 
(Bug 81038, Bug 23088916)

The version of the tcmalloc library included in MySQL distributions was very \ 
old. It has been removed and is no longer included with MySQL. (Bug 80994, Bug \ 
23068660)

Bugs Fixed

InnoDB: MySQL failed to build on Fedora 24 using GCC 6. (Bug 23227804)

InnoDB: Potential buffer overflow issues were corrected for the InnoDB memcached \ 
plugin. (Bug 23187607)

InnoDB: The full-text index cache was freed during a background index cache \ 
synchronization. (Bug 22996488)

InnoDB: A full-text index operation raised an assertion. (Bug 22963169)

InnoDB: An INSERT operation on a table with a FULLTEXT index and FTS_DOC_ID \ 
column failed because the inserted FTS_DOC_ID value exceeded the permitted gap \ 
between consecutive FTS_DOC_ID values. To avoid this problem, the permitted gap \ 
between the largest used FTS_DOC_ID value and new FTS_DOC_ID value was raised \ 
from 10000 to 65535. (Bug 22679185)

InnoDB: With innodb_autoinc_lock_mode=0, multiple threads waiting for a \ 
table-level lock caused an unexpected deadlock. (Bug 21983865, Bug 78761)

InnoDB: A FLUSH TABLES ... FOR EXPORT operation appeared to stall. A loop in the \ 
ibuf_contract_in_background function failed to exit. (Bug 21133329, Bug 77011)

InnoDB: A full-text query raised an assertion. Under certain circumstances, DDL \ 
operations such as ALTER TABLE ... RENAME caused full-text auxiliary tables to \ 
be removed on server restart. (Bug 13651665)

Replication: In the next_event() function, which is called by a slave's SQL \ 
thread to read the next even from the relay log, the SQL thread did not release \ 
the relaylog.log_lock it acquired when it ran into an error (for example, due to \ 
a closed relay log), causing all other threads waiting to acquire a lock on the \ 
relay log to hang. With this fix, the lock is released before the SQL thread \ 
leaves the function under the situation. (Bug 21697821)

References: See also: Bug 20492319.

Replication: If a multi-threaded replication slave running with \ 
relay_log_recovery=1 stopped unexpectedly, during restart the relay log recovery \ 
process could fail. This was due to transaction inconsistencies not being \ 
filled, see Handling an Unexpected Halt of a Replication Slave. Prior to this \ 
fix, to recover from this situation required manually setting \ 
relay_log_recovery=0, starting the slave with START SLAVE UNTIL \ 
SQL_AFTER_MTS_GAPS to fix any transaction inconsistencies and then restarting \ 
the slave with relay_log_recovery=1. This process has now been automated, \ 
enabling relay log recovery of a multi-threaded slave upon restart \ 
automatically. (Bug 77496, Bug 21507981)

INSERT with ON DUPLICATE KEY UPDATE and REPLACE on a table with a foreign key \ 
constraint defined failed with an incorrect “duplicate entry” error \ 
rather than a foreign key constraint violation error. (Bug 23135731)

References: This issue is a regression of: Bug 78853, Bug 22037930.

For debug builds, CONCAT_WS() could raise an assertion if there was nothing to \ 
append. (Bug 22888420)

Invoking Enterprise Encryption functions in multiple threads simultaneously \ 
could cause a server exit. (Bug 22839278)

Attempting to use Enterprise Encryption functions after creating and dropping \ 
them could cause a server exit. (Bug 22669012)

Setting sort_buffer_size to a very large value could cause some operations to \ 
fail with an out-of-memory error. (Bug 22594514)

An assertion could be raised when a deadlock occurred due to a SELECT ... GROUP \ 
BY ... FOR UPDATE query executed using a Loose Index Scan. (Bug 22187476)

Several potential buffer overflow issues were corrected. (Bug 21977380, Bug \ 
23187436, Bug 23202778, Bug 23195370, Bug 23202699)

If the CA certificate as given to the --ssl-ca option had an invalid path, yaSSL \ 
returned an error message different from OpenSSL. Now both return SSL connection \ 
error: SSL_CTX_set_default_verify_paths failed. (Bug 21920657)

Some string functions returned one or a combination of their parameters as their \ 
result. If one of the parameters had a non-ASCII character set, the result \ 
string had the same character set, resulting in incorrect behavior when an ASCII \ 
string was expected. (Bug 18740222)

On Windows, MySQL installation could result in MySQL being placed under \ 
C:\Program Files\Canon\Easy-WebPrint EX. (Bug 14583183)

References: See also: Bug 70918, Bug 68821, Bug 68227.

On Fedora 24, upgrades using a Community MySQL Server RPM failed to replace an \ 
installed MariaDB Galera server due to a change in the MariaDB package. (Bug \ 
81390, Bug 23273818)

MySQL did not compile under Solaris 12 using Sun Studio. To correct this, \ 
instances of __attribute__ were changed to MY_ATTRIBUTE. (Bug 80748, Bug \ 
22932576)

The INSTALL-SOURCE file had partly outdated information and has been removed \ 
from source packages. (Binary packages are unaffected). (Bug 80680, Bug \ 
23081064)

For a server compiled with -DWITH_PERFSCHEMA_STORAGE_ENGINE=0, a memory leak \ 
could occur for buffered log messages used during server startup. (Bug 80089, \ 
Bug 22578574)

For debug builds, merging a derived table into an outer query block could raise \ 
an assertion. (Bug 79502, Bug 22305361, Bug 21139722)

A null pointer dereference of a parser structure could occur during stored \ 
procedure name validation. (Bug 79396, Bug 22286421)

Using CREATE USER to create an account with the mysql_native_password or \ 
mysql_old_password authentication plugin and using a clause of the form \ 
IDENTIFIED WITH plugin AS 'hash_string' caused the account to be created without \ 
a password. (Bug 78033, Bug 21616496)

Failure of UNINSTALL PLUGIN could lead to inaccurate or confusing errors for \ 
subsequent INSTALL PLUGIN operations. (Bug 74977, Bug 20085672)

mysqld_multi displayed misleading error messages when it was unable to execute \ 
my_print_defaults. (Bug 74636, Bug 19920049)

On Windows, MySQL installation failed if the \ 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ registry \ 
key was present with a key/value pair of "InstallLocation" and \ 
"\Hewlett-Packard\\". (Bug 74631, Bug 19949163)

mysqldump failed silently with no error message when it encountered an error \ 
while executing FLUSH LOGS.