CRASHES ON EVERY START ATTEMPT

Description:
------------
push_warning_printf function is used to print the warning message
to the client. So this function should not invoke while recovering
the server. Moreover current_thd is NULL while starting the server.

Solution:
---------
 - Avoiding the warning to be printed while recovery.
This patch already pushed in mysql-5.6.

	- Moving the test case to correct place.

Patch for 5.5

              CODE

Fixed a failure on pb2 caused by the patch previously
pushed.

Generated new certificates with validity upto 2029.

              CODE

Problem: UDF doesn't handle the arguments properly when they
         are of string type due to a misplaced break.
         The length of arguments is also not set properly
         when the argument is NULL.

Solution: Fixed the code by putting the break at right place
          and setting the argument length to zero when the
          argument is NULL.

Description: When querying a subset of columns from the information_schema.TABLES

Analysis: When information about tables is collected for statements like
"SELECT ENGINE FROM I_S.TABLES" we do not perform full-blown table opens
in SE, instead we only use information from table shares from the Table
Definition Cache or .FRMs. Still in order to simplify I_S implementation
mock TABLE objects are created from TABLE_SHARE during this process.
This is done by calling open_table_from_share() function with special
arguments. Since this function always increments "Opened_tables" counter,
calls to it can be mistakingly interpreted as full-blown table opens in SE.

Note that claim that "'SELECT ENGINE FROM I_S.TABLES' statement doesn't
use Table Cache" is nevertheless factually correct. But it misses the
point, since such statements a) don't use full-blown TABLE objects and
therefore don't do table opens b) still use Table Definition Cache.

Fix: We are now incrementing the counter when db_stat(i.e open flags for ha_open(

we have considered an optimization which would use TABLE objects from
Table Cache when available instead of constructing mock TABLE objects,
but found it too intrusive for stable releases.

Analysis:
--------
Certain queries using intrinsic temporary tables may fail due to
name clashes in the file name for the temporary table when the
'temp-pool' enabled.

'temp-pool' tries to reduce the number of different filenames used for
temp tables by allocating them from small pool in order to avoid
problems in the Linux kernel by using a three part filename:
<tmp_file_prefix>_<pid>_<temp_pool_slot_num>.
The bit corresponding to the temp_pool_slot_num is set in the bit
map maintained for the temp-pool when it used for the file name.
It is cleared after the temp table is deleted for re-use.

The 'create_tmp_table()' function call under error condition
tries to clear the same bit twice by calling 'free_tmp_table()'
and 'bitmap_lock_clear_bit()'. 'free_tmp_table()' does a delete
of the table/file and clears the bit by calling the same function
'bitmap_lock_clear_bit()'.

The issue reported can be triggered under the timing window mentioned
below for an error condition while creating the temp table:
a) THD1: Due to an error clears the temp pool slot number used by it
   by calling 'free_tmp_table'.
b) THD2: In the process of creating the temp table by using an unused
   slot number in the bit map.
c) THD1: Clears the slot number used THD2 by calling
  'bitmap_lock_clear_bit()' after completing the call 'free_tmp_table'.
d) THD3: Uses the slot number used the THD2 since it is freed by THD1.
   When it tries to create the temp file using that slot number,
   an error is reported since it is currently in use by THD2.
   [The error: Error 'Can't create/write to file
   '/tmp/#sql_277e_0.MYD' (Errcode: 17)']

Another issue which may occur in 5.6 and trunk is that:
When the open temporary table fails after its creation(due to ulimit
or OOM error), the file is not deleted. Thus further attempts to use
the same slot number in the 'temp-pool' results in failure.

Fix:
---
a) Under the error condition calling the 'bitmap_lock_clear_bit()'
   function to clear the bit is unnecessary since 'free_tmp_table()'
   deletes the table/file and clears the bit. Hence removed the
   redundant call 'bitmap_lock_clear_bit()' in 'create_tmp_table()'
   This prevents the timing window under which the issue reported
   can be seen.

b) If open of the temporary table fails, then the file is deleted
   thus allowing the temp-pool slot number to be utilized for the
   subsequent temporary table creation.

c) Also if the attempt to create temp table fails since it already
   exists, the temp-pool slot for it is marked as used, to avoid
   the problem from re-appearing.

Change the format of 'git log' to produce INFO_SRC:

commit: <commit hash>
date: 2014-11-12 11:11:10 +0100
build-date: 2014-11-17 15:24:16 +0100
short: <abbreviated commit hash>
branch: mysql-5.5

Use 'git ls-files' to find source files for etags.

Use 'git log -1; git branch' rather than 'bzr version-info'

For 'make dist': only use 'bzr export' if bzr root == ${CMAKE_SOURCE_DIR}
Same thing for git.

               COMMUNICATION PACKETS; FEDERATED TABLE

Description:- Execution of FLUSH TABLES on a federated
table which has been idle for wait_timeout (on the remote
server) + tcp_keepalive_time, fails with an error,
"ERROR 1160 (08S01): Got an error writing communication
packets."

Analysis:- During FLUSH TABLE execution the federated
table is closed which will inturn close the federated
connection. While closing the connection, federated server
tries to communincate with the remote server. Since the
connection was idle for wait_timeout(on the remote server)+
tcp_keepalive_time, the socket gets closed. So this
communication fails because of broken pipe and the error is
thrown. But federated connections are expected to reconnect
silently. And also it cannot reconnect because the 
"auto_reconnect" variable is set to 0 in "mysql_close()".

Fix:- Before closing the federated connection, in
"ha_federated_close()", a check is added which will verify
wheather the connection is alive or not. If the connection
is not alive, then "mysql->net.error" is set to 2 which
will indicate that the connetion is broken. Also the
setting of "auto_reconnect" variable to 0 is delayed and is
done after "COM_QUIT" command.
      
NOTE:- For reproducing this issue, "tcp_keepalive_time" has
to be set to a smaller value. This value is set in the
"/proc/sys/net/ipv4/tcp_keepalive_time" file in Unix
systems. So we need root permission for changing it, which
can't be done through mtr test. So submitting the patch
without mtr test.

Fix broken gcc 4.9.1 debug build by removing end of line noise.

In 5.6+ this issue was already fixed by:
------------------------------------------------------------
revno: 3091
committer: Davi Arnaut <davi.arnaut@oracle.com>
branch nick: mysql-trunk
timestamp: Mon 2011-05-16 11:30:54 -0300
message:
  Fix warnings emitted by Clang.

When building RPMs and using the "rpmbuild" automatic scanning for
Perl dependencies, it might interpret "use hostnames" in the
"mysql_config.pl" script usage comment as a Perl "use" statement.
And then makes the resulting RPMs depends on a non-existing module
Perl "hostnames". The comment was changed to prevent this.

Description:
  Using correct length when moving to next field in cmp_ref. The store
length already includes the length bytes of blobs, which is already considered
earlier for blob types.
	Approved by Mattias, Jimmy [rb-7088] 

Issue :
-------
This seems for some platform -(LONGLONG_MIN) is
not flagged as out of range.

Fix:
----
Fix is backported from mysql-5.6 bug 14314156.
Fixed by adding an explicit test for this value in
Item_func_neg::int_op().

The debug configuration parameter innodb_optimistic_insert_debug
which was introduced for testing corner cases in B-tree handling
had a bug in it. The value 1 would trigger an infinite sequence
of page splits.

Fix: When the value 1 is specified, disable this debug feature.
Approved by Yasufumi Kinoshita

Problem:

In the function dict_foreign_remove_from_cache(), the rb tree was updated
without actually verifying whether the given foreign key object is there in the
rb tree or not.  There can be an existing foreign key object with the same id 
in the rb tree, which must not be removed.  Such a scenario comes when an
attempt is made to add a foreign key object with a duplicate identifier.

Solution:

When the foreign key object is removed from the dictionary cache, ensure
that the foreign key object removed from the rbt is the correct one.

rb#7168 approved by Jimmy and Marko.

dict_set_corrupted(): Use the canonical way of searching for
less-than-equal (PAGE_CUR_LE) and then checking low_match.

The code that was introduced in MySQL 5.5.17 in
    Bug#11830883 SUPPORT "CORRUPTED" BIT FOR INNODB TABLES AND INDEXES
could position the cursor on the page supremum, and then attempt
to overwrite non-existing 7th field of the 1-field supremum record.

Approved by Jimmy Yang

Description:- Replace, the string replacement utility fails
on the windows platform.

Analysis:- The utility takes files and multiple string
pairs as input. In the windows platform, the utility maps
the standard input incorrectly (Considers 0 as the fd for
standard input instead of 2048 on windows). Hence when the
input file is supplied to the utility due to the incorrect
mapping, a bad file descriptor error is generated causing
the utility to exit with an error.

Fix:- "my_fileno()" is used for getting the correct file
despscriptor for standard input.

some of the tables are created in InnoDB and some tables are created in MyISAM.
We need to create all tables on InnoDB.  Fix is to add engine=innodb to the
CREATE TABLE statements.  

approved in IM by Marko and Vasil.

Description: Certain operations using the client tool
'mysql\_setpermisson' which uses username of the format 
"xxx-yyy" results in a syntax error.

Analysis: The user name variable ( $user ) was not quoted
properly in the 'mysql\_setpermission' script. As a result,
while granting user privileges for a user with username of
the format 'xxx-yyy', results in a syntax error.

Fix: The escape sequence has been applied for the user
variable in the script file.

Note: Test case is not added for this fix.
'mysql\_setpermission' executable resides in different
directories on pb2 machines and on local boxes. Hence the 
test case cannot be made generic.

Bug#17959689: MAKE GCC AND CLANG GIVE CONSISTENT COMPILATION WARNINGS
Bug#18313717: ENABLE -WERROR IN MAINTANER MODE WHEN COMPILING WITH CLANG
Bug#18510941: REMOVE CMAKE WORKAROUNDS FOR OLDER VERSIONS OF OS X/XCODE
  
Backport from mysql-5.6 to mysql-5.5

Problem: For every event read, mysqlbinlog calls localtime() which in turn
calls stat(/etc/localtime) which is causing kernel mutex contention.

Analysis and Fix:
localtime() calls stat(/etc/localtime) for every instance of the call
where as localtime_r() the reentrant version was optimized to store
the read only tz internal structure. Hence it will not call
stat(/etc/localtime). It will call only once at the beginning.
The mysql server is calling localtime_r() and mysqlbinlog tool is
one place where we are still using localtime().

Once the process (mysqlbinlog) is started if timezone is changed
it will be not picked up the the process and it will continue
with the same values as the beginning of the process. This
behavior is in-lined with mysql server.

Also adding localtime_r() and gmtime_r() support for windows.

Problem:
========
In a master slave replication if a slave receives a
Start_log_event_v3 the payload is expected to be of fixed
size. If a payload which is smaller than the fixed size is
received it causes a read out of bounds issue.

Analysis:
========
According to documentation the fixed data part of
Start_log_event_v3 looks as shown below.

2 bytes: The binary log format version
50 bytes: The MySQL server's version
4 bytes: Timestamp in seconds when this event was created

Since the payload is expected to be of fixed size, therefore
ST_SERVER_VER_LEN (50) bytes are memcpy'ed into
server_version. But if a malicious master sends a shorter
payload it causes a read out of bounds issue.

Fix:
===
In Start_log_event_v3 event's constructor a check has been
added which expects the minimum payload length to be of size
common_header_len + ST_COMMON_HEADER_LEN_OFFSET bytes. If a
malicious packet of lesser length is received it will be
considered as an invalid event.

 - Restarting mysqld with --expire-log-days=1 triggers 'log_in_use()' to be called while current_thd is NULL.
 - Check current_thd before calling DEBUG_SYNC() to avoid passing NULL pointer to DEBUG_SYNC()
 - Wrap debug code construct inside #ifndef DBUG_OFF like in other parts of the file

Normally, SET SESSION SQL_LOG_BIN is used by DBAs to run a
non-conflicting command locally only, ensuring it does not
get replicated.
Setting GLOBAL SQL_LOG_BIN would not require all sessions to
disconnect. When SQL_LOG_BIN is changed globally, it does not
immediately take effect for any sessions. It takes effect by
becoming the session-level default inherited at the start of
each new session, and this setting is kept and cached for the
duration of that session. Setting it intentionally is unlikely
to have a useful effect under any circumstance; setting it
unintentionally, such as while intending to use SET [SESSION]
is potentially disastrous. Accidentally using SET GLOBAL
SQL_LOG_BIN will not show an immediate effect to the user,
instead not having the desired session-level effect, and thus
causing other potential problems with local-only maintenance
being binlogged and executed on slaves; And transactions from
new sessions (after SQL_LOG_BIN is changed globally) are not
binlogged and replicated, which would result in irrecoverable
or difficult data loss.
This is the regular GLOBAL variables way to work, but in
replication context it does not look right on a working server
(with connected sessions) 'set global sql_log_bin' and none of
that connections is affected. Unexperienced DBA after noticing
that the command did "nothing" will change the session var and
most probably won't unset the global var, causing new sessions
to not be binlog.
Setting GLOBAL SQL_LOG_BIN allows DBA to stop binlogging on all
new sessions, which can be used to make a server "replication
read-only" without restarting the server. But this has such big
requirements, stop all existing connections, that it is more
likely to make a mess, it is too risky to allow the GLOBAL variable.

The statement 'SET GLOBAL SQL_LOG_BIN=N' will produce an error
in 5.5, 5.6 and 5.7. Reading the GLOBAL SQL_LOG_BIN will produce
a deprecation warning in 5.7.

FROM A FUNCTION

Scenario:

In a stored procedure, CREATE TABLE statement is not allowed.  But an
exception is provided for CREATE TEMPORARY TABLE.  We can create a temporary
table in a stored procedure.

Let there be two stored functions f1 and f2 and two stored procedures p1 and
p2.  Their properties are as follows:

. stored function f1() calls stored procedure p1().
. stored function f2() calls stored procedure p2().
. stored procedure p1() creates temporary table t1.
. stored procedure p2() does DML on t1.

Consider the following situation:

1.  Autocommit mode is on. 
2.  select f1()
3.  select f2()

Step 2:  In this step, t1 would be created via p1().  A table level transaction
lock would have been taken.  The ::external_lock() would not have been called
on this table.  At the end of step 2, because of autocommit mode on, this table
level lock will be released.

Step 3:  When we execute DML on table t1 via p2() we have two problems:

Problem 1:

The function ha_innobase::external_lock() would have been called but since
it is a select query no table level locks would have been taken.  Hence the
following assert will fail:

ut_ad(lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));

Solution:

The solution would be to identify this situation and take a table level lock
and use the proper lock type prebuilt->select_lock_type = LOCK_X for DML
operations.

Problem 2:

Another problem is that in step 3, ha_innobase::open() is never called on
the table t1.  

Solution:

The solution would be to identify this situation and call re-init the handler
of table t1.

rb#6429 approved by Krunal.