Problem:-
We have created a table with UTF8_BIN collation.
In case, when in our query we have ORDER BY clause over a function 
call we are getting result in incorrect order.
Note:the bug is not there in 5.5.

Analysis:
In 5.5, for UTF16_BIN, we have min and max multi-byte length is 2 and 4 
respectively.In make_sortkey(),for 2 byte character character we are 
assuming that the resultant length will be 2 byte/character. But when we 
use my_strnxfrm_unicode_full_bin(), we store sorting weights using 3 bytes 
per character.This result in truncated result.

Same thing happen for UTF8MB4, where we have 1 byte min multi-byte and 
4 byte max multi-byte.We will accsume resultant data as 1 byte/character, 
which result in truncated result.

Solution:-
use strnxfrm(means use of MY_CS_STRNXFRM macro) is used for sort, in 
which the resultant length is not dependent on source length.

No commit message

"SHOW BINLOG EVENTS"

Problem:
========
mysql was crashed after executing "show binlog events in
'mysql-bin.000005' from 99", the crash happened randomly.

Analysis:
========
During construction of LOAD EVENT or NEW LOAD EVENT object
if the starting offset is provided as incorrect value then
all the object members that are retrieved from the offset
are also invalid.  Some times it will lead to out of bound
address offsets.  In the bug scenario, the file name is
extracrated from an invalid address and the same is fed to
strlen(fname) function. Passing invalid address to strlen
will lead to crash.

Fix:
===
Validate if the given offset falls within the event boundary
or not.

               CAN RETURN WRONG RESULT SET

PROBLEM
-------
In ha_partition::cmp_ref() we were only calling the 
underlying cmp_ref() of storage engine if the records
are in the same partiton,else we sort by partition and
returns the result.But the index merge intersect 
algorithm expects first to sort by row-id first and 
then by partition id.

FIX
---
Compare the refernces first using storage engine cmp_ref
and then if references are equal(only happens if 
non clustered index is used) then sort it by partition id.

[Approved by Mattiasj #rb3755]
-

Item_func_trim::val_str: we were using the non-mb algorithm for skipping leading spaces
in a multibyte-charset string.

    UPPER CASE HOST NAME ANYMORE
Null merge from mysql-5.1 to mysql-5.5

No commit message

get_cost_calc_buff_size() could return wrong value for the size of imerge_cost_buff.

No commit message

No commit message

No commit message

    UPPER CASE HOST NAME ANYMORE
Merging from mysql-5.1 to mysql-5.5

    UPPER CASE HOST NAME ANYMORE

Description:
It is not possible to drop users with host names with upper case
letters in them. i.e DROP USER 'root'@'Tmp_Host_Name'; is failing
with error.

Analysis: Since the fix 11748570 we came up with lower case hostnames
as standard. But in the current bug the hostname is created by
mysql_install_db script is still having upper case hostnames. 
So, if we have the hostname with upper case letters like(Tmp_Host_Name)
then we will have as it is stored in the mysql.user table. 
In this case if use "'DROP USER 'root'@'Tmp_Host_Name';" it gives 
error because we do compare with the lower case of hostname since the 
11748570 fix.

Fix: We need to convert the hostname to lower case before storing into 
the mysql.user table when we run the mysql_install_db script.

No commit message

possibly since it was introduced in the patch for Bug#16720368 around 
2013-04-30.  This fix is simply to adjust the mtr.add_suppression() lines
in the testcase and to add a missing "\n" in the error message.

Approved by Marko in RB 3746

The filesort implementation needs space for at least 15 records
(plus some internal overhead) in its main sort buffer.

No commit message

-Wl,--no-undefined (=-z defs) gives linking errors when used with WITH_ASAN.
According to the documentation:
"When linking shared libraries, the AddressSanitizer run-time is not linked,
so -Wl,-z,defs may cause link errors (don’t use it with AddressSanitizer)."

This patch turns off -Wl,--no-undefined if WITH_ASAN is used.

               ON DELETE FROM A PARTITIONED TABLE

PROBLEM
-------

The user first disables all the non unique indexes
in the table and then rebuilds one partition.
During rebuild the indexes on that particular
partition are enabled. Now when we give a query 
the optimizer is unaware that on one partition 
indexes are enabled and if the optimizer selects
that index,myisam thinks that the index is not 
active and gives an error.

FIX
---

Before rebuilding a partition check whether non
unique indexes are disabled on the partitons.
If they are disabled then after rebuild disable
the index on the partition. 

[Approved by Mattiasj #rb3469]

Too restrictive assertion, failing during purge

Too restrictive assertion, can fail during purge

Regression from bug#14621190 due to disabled optimistic restoration
of cursor, which required full key lookup instead of verifying
if previously positioned btree cursor could be reused.

Fixed by enable optimistic restore and adjust cursor afterward.

rb#3324 approved by Marko.

Problem:
COM_CHANGE_USER allows brute-force attempts to crack a password at a very high
rate as it does not cause any significant delay after a login attempt has
failed. This issue was reproduced using John-The-Ripper password
cracking tool through which about 5000 passwords per second could be attempted.

Solution:
The non-GA version's solution was to disconnect the connection when a login
attempt failed. Now since our aim to to reduce the rate at which passwords 
are tested, we introduced a sleep(1) after every login attempt failed. This
significantly increased the delay with which the password was cracked.

Automerged from mysql-5.5 bug branch into latest mysql-5.5.

             AS A INNODB PARTITTION.
[Merged from 5.1]             

             AS A INNODB PARTITTION.

PROBLEM
-------
The correct engine_type was not being set during 
rebuild of the partition due to which the handler
was always created with the default engine,
which is innodb for 5.5+ ,therefore even if the
table was myisam, after rebuilding the partitions
ended up as innodb partitions.

FIX
---
Set the correct engine type during rebuild.  

[Approved by mattiasj #rb3599]

The assertion happens when: (i) the master and slave are configured to
use the semisync plugin; (ii) the DBA disables semisync on the master;
(iii) and he also unsets the option to wait for slaves ACK even if the
semisync slave count reaches 0 during the waiting period. This
combination of factors makes the server run into an assertion as soon
as the last semisync slave disconnects and its dump thread exits.
  
The root of the problem is the fact that when the dump thread
disconnects and calls the observer hook transmit_stop, which ends up
calling ReplSemiSyncMaster::remove_slave, there is no check whether
the master has already disabled semisync or not. If it has, the then a
second call to the switch_off member function must be avoided.
  
The quick fix is to avoid calling switch_off if the DBA has disabled
the semisync plugin interactively on the master. Also, the switch_off
member function should only be called if the plugin has not been
switched off already. This is basically the pattern throughout the
rest of the semisync plugin and no other calls seem vulnerable to
similar crashes/assertions.

(This a backport of the patch to 5.5, which is also vulnerable.)

--Implemented CHECK TABLE...QUICK.
  Introduce CHECK TABLE...QUICK that would skip the btr_validate_index()
  and btr_search_validate() call, and count the no. of records in each index.

Approved by Marko and Kevin. (rb#3567).

No commit message

Merging mysql-5.5 bug branch into latest mysql-5.5.

REPLICATION FILTERS ARE USED.
Merging fix from mysql-5.1