Facebook got a case where the page compresses really well so that
btr_cur_optimistic_update() returns DB_UNDERFLOW, but when a record
gets updated, the compression rate radically changes so that
btr_cur_insert_if_possible() can not insert in place despite
reorganizing/recompressing the page, leading to the assertion failing.

rb:1220 approved by Sunny Bains

COMPRESSED PAGE SIZE

This was submitted as MySQL Bug 61456 and a patch provided by
Facebook. This patch follows the same idea, but instead of adding a
parameter to btr_cur_pessimistic_insert(), we simply remove the
btr_cur_optimistic_insert() call there and add it to the only caller
that needs it.

btr_cur_pessimistic_insert(): Do not try btr_cur_optimistic_insert().

btr_insert_on_non_leaf_level_func(): Invoke btr_cur_optimistic_insert()
before invoking btr_cur_pessimistic_insert().

btr_cur_pessimistic_update(): Clarify in a comment why it is not
necessary to invoke btr_cur_optimistic_insert().

btr_root_raise_and_insert(): Assert that the root page is not empty.
This could happen if a pessimistic insert (involving a split or merge)
is performed without first attempting an optimistic (intra-page) insert.

rb:1219 approved by Sunny Bains

btr_cur_optimistic_insert(): Remove a bogus assertion. The insert may
fail after reorganizing the page.

btr_cur_optimistic_update(): Do not attempt to reorganize compressed pages,
because compression may fail after reorganization.

page_copy_rec_list_start(): Use page_rec_get_nth() to restore to the
ret_pos, which may also be the page infimum.

rb:1221

MASTER-MASTER AND USING SET USE

Problem:
=======
In a master-master set-up, a master can show a wrong
'SHOW SLAVE STATUS' output.

Requirements:
- master-master
- log_slave_updates

This is caused when using SET user-variables and then using
it to perform writes. From then on the master that performed
the insert will have a SHOW SLAVE STATUS that is wrong and  
it will never get updated until a write happens on the other
master. On"Master A" the "exec_master_log_pos" is not
getting updated.

Analysis:
========
Slave receives a "User_var" event from the master and after
applying the event, when "log_slave_updates" option is
enabled the slave tries to write this applied event into
its own binary log. At the time of writing this event the
slave should use the "originating server-id". But in the
above case the sever always logs the  "user var events"
by using its global server-id. Due to this in a
"master-master" replication when the event comes back to the
originating server the "User_var_event" doesn't get skipped.
"User_var_events" are context based events and they always
follow with a query event which marks their end of group.
Due to the above mentioned problem with "User_var_event"
logging the "User_var_event" never gets skipped where as
its corresponding "query_event" gets skipped. Hence the
"User_var" event always waits for the next "query event"
and the "Exec_master_log_position" does not get updated
properly.

Fix:
===
`MYSQL_BIN_LOG::write' function is used to write events
into binary log. Within this function a new object for
"User_var_log_event" is created and this new object is used
to write the "User_var" event in the binlog. "User var"
event is inherited from "Log_event". This "Log_event" has
different overloaded constructors. When a "THD" object
is present "Log_event(thd,...)" constructor should be used
to initialise the objects and in the absence of a valid
"THD" object "Log_event()" minimal constructor should be
used. In the above mentioned problem always default minimal
constructor was used which is incorrect. This minimal
constructor is replaced with "Log_event(thd,...)".

               CONNECTIONS IF SPE

Problem description: -ssl-key value is not validated, you can assign any bogus 
text to --ssl-key and it is not verified that it exists, and more importantly, 
it allows the client to connect to mysqld.

Fix: Added proper validations checks for --ssl-key.

Note:
1) Documentation changes require for 5.1, 5.5, 5.6 and trunk in the sections
   listed below and the details are :

 http://dev.mysql.com/doc/refman/5.6/en/ssl-options.html#option_general_ssl
    and
 REQUIRE SSL section of
 http://dev.mysql.com/doc/refman/5.6/en/grant.html

2) Client having with option '--ssl', should able to get ssl connection. This 
will be implemented as part of separate fix in 5.6 and trunk.

When resolving outer fields, Item_field::fix_outer_fields()
creates new Item_refs for each execution of a prepared statement, so
these must be allocated in the runtime memroot. The memroot switching
before resolving JOIN::having causes these to be allocated in the
statement root, leaking memory for each PS execution.

IN QUERIES

This bug was caused by an incorrect fix of
Bug#13807811 BTR_PCUR_RESTORE_POSITION() CAN SKIP A RECORD

There was nothing wrong with btr_pcur_restore_position(), but with the
use of it in the table scan during index creation.

rb:1206 approved by Jimmy Yang

WHEN STDIN IS A PIPE
            
Problem: Mysqlbinlog does not accept the input from STDIN when 
STDIN is a pipe. This prevents the users from passing the input file
through a shell pipe.    

Background: The my_seek() function does not check if the file descriptor
passed to it is regular (seekable) file. The check_header() function in
mysqlbinlog calls the my_b_seek() unconditionally and it fails when
the underlying file is a PIPE.  
            
Resolution: We resolve this problem by checking if the underlying file
is a regular file by using my_fstat() before calling my_b_seek(). 
If the underlying file is not seekable we skip the call to my_b_seek()
in check_header().

             SHOW 2012 INSTEAD OF 2011

* Added a new macro to hold the current year :
  COPYRIGHT_NOTICE_CURRENT_YEAR
* Modified ORACLE_WELCOME_COPYRIGHT_NOTICE macro
  to take the initial year as parameter and pick
  current year from the above mentioned macro.

              AND LIBCRYPTO

Problem: libmysqlclient_r exports symbols from yaSSL library which
         conflict with openSSL symbols. This issue is related to symbols
         used by CURL library and are defined in taocrypt. Taocrypt has
         dummy implementation of these functions. Due to this when a
         program which uses libcurl library functions is compiled using
         libmysqlclient_r and libcurl, it hits segmentation fault in
         execution phase.

Solution: MySQL should not be exporting such symbols. However, these
          functions are not used by MySQL code at all. So avoid compiling
          them in the first place.

Backport the fix from 5.6 to 5.1
Base bug number : 11765562

Space available for merging was calculated incorrectly.

Fixed the missing of federated/include folder at the time 
of preparing package distribution, issue happens only in 5.1

               IS PLACE HOLDER AND USE SERVER-SIDE 

Analysis:
LIMIT always takes nonnegative integer constant values. 

http://dev.mysql.com/doc/refman/5.6/en/select.html

So parsing of value '5' for LIMIT in SELECT fails.

But, within prepared statement, LIMIT parameters can be
specified using '?' markers. Value for the parameter can
be supplied while executing the prepared statement.

Passing string values, float or double value for LIMIT
works well from CLI. Because, while setting the value
for the parameters from the variable list (added using
SET), if the value is for parameter LIMIT then its 
converted to integer value. 

But, when prepared statement is executed from the other
interfaces as J connectors, or C applications etc.
The value for the parameters are sent to the server
with execute command. Each item in log has value and
the data TYPE. So, While setting parameter value
from this log, value is set to all the parameters
with the same data type as passed.
But here logic to convert value to integer type
if its for LIMIT parameter is missing.
Because of this,string '5' is set to LIMIT.
And the same is logged into the binlog file too. 

Fix:
When executing prepared statement having parameter for
CLI it worked fine, as the value set for the parameter
is converted to integer. And this failed in other 
interfaces as J connector,C Applications etc as this 
conversion is missing.

So, as a fix added check while setting value for the
parameters. If the parameter is for LIMIT value then
its converted to integer value.

Fix for pb2 test failure.

             WORK + SAVES ROOT PASSWORD TO DISK!

The secure installation scripts connect to the
server by storing the password in a temporary
option file. Now, if the script gets killed or
fails for some reason, the removal of the option
file may not take place.

This patch introduces following enhancements :
* (.sh) Made sure that cleanup happens at every
  call to 'exit 1'. This is performed implicitly
  by END{} in pl.in.
* (.pl.in) Added a warning in case unlink fails
  to delete the option/query files.
* (.sh/.pl.in) Added more signals to the signal
  handler list. SIG# 1, 3, 6, 15

Problem description:
Table 't' created with two colums having compound index on both the 
columns under innodb/myisam engine at remote machine. In the local 
machine same table is created undet the federated engine.
A select having where clause with along 'AND' operation gives wrong 
results on local machine.

Analysis: 
The given query at federated engine is wrongly transformed by 
federated::create_where_from_key() function and the same was sent to 
the remote machine. Hence the local machine is showing wrong results.

Given query "select c1 from t where c1 <= 2 and c2 = 1;"
Query transformed, after ha_federated::create_where_from_key() function is:
SELECT `c1`, `c2` FROM `t` WHERE  (`c1` IS NOT NULL ) AND 
( (`c1` >= 2)  AND  (`c2` <= 1) ) and the same sent to real_query().
In the above the '<=' and '=' conditions were transformed to '>=' and 
'<=' respectively.

ha_federated::create_where_from_key() function behaving as below:
The key_range is having both the start_key and end_key. The start_key 
is used to get "(`c1` IS NOT NULL )" part of the where clause, this 
transformation is correct. The end_key is used to get "( (`c1` >= 2) 
AND  (`c2` <= 1) )", which is wrong, here the given conditions('<=' and '=') 
are changed as wrong conditions('>=' and '<=').
The end_key is having {key = 0x39fa6d0 "", length = 10, keypart_map = 3, 
flag = HA_READ_AFTER_KEY}

The store_length is having value '5'. Based on store_length and length 
values the condition values is applied in HA_READ_AFTER_KEY switch case.
The switch case 'HA_READ_AFTER_KEY' is applicable to only the last part of 
the end_key and for previous parts it is going to 'HA_READ_KEY_OR_NEXT' case, 
here the '>=' is getting added as a condition instead of '<='.

Fix:
Updated the 'if' condition in 'HA_READ_AFTER_KEY' case to affect for all 
parts of the end_key. i.e 'i > 0' will used for end_key, Hence added it in 
the if condition.

Backporting the WL#5716, "Information schema table for InnoDB 
buffer pool information". Backporting revisions 2876.244.113, 
2876.244.102 from mysql-trunk.

rb://1175 approved by Jimmy Yang. 

while the copyright notice still mentioned 2003.

  Added new minimal client using same framework
  Added internal test using it
  Small changes to top level make/configure/cmake to have it built

Problem description:
Giving "help 'contents'" in the mysql client as a first statement
gives error

Analysis:
In com_server_help() function the "server_cmd" variable was
initialised with buffer->ptr(). And the "server_cmd" variable is not
updated since we are passing "'contents'"(with single quote) so the
buffer->ptr() consists of the previous buffer values and it was sent
to the mysql_real_query() hence we are getting error.

Fix:
We are not initialising the "server_cmd" variable and we are updating
the variable with "server_cmd= cmd_buf" in any of the case i.e with
single quote or without single quote for the contents.
As part of error message improvement, added new error message in case
of "help 'contents'".

                     "ORDER BY" AND "LIMIT BY" CLAUSE

PROBLEM:
When a 'limit' clause is specified in a query along with
group by and order by, optimizer chooses wrong index
there by examining more number of rows than required.
However without the 'limit' clause, optimizer chooses
the right index.

ANALYSIS:
With respect to the query specified, range optimizer chooses
the first index as there is a range present ( on 'a'). Optimizer
then checks for an index which would give records in sorted
order for the 'group by' clause.

While checking chooses the second index (on 'c,b,a') based on
the 'limit' specified and the selectivity of
'quick_condition_rows' (number of rows present in the range)
in 'test_if_skip_sort_order' function. 
But, it fails to consider that an order by clause on a
different column will result in scanning the entire index and 
hence the estimated number of rows calculated above are 
wrong (which results in choosing the second index).

FIX:
Do not enforce the 'limit' clause in the call to
'test_if_skip_sort_order' if we are creating a temporary
table. Creation of temporary table indicates that there would be
more post-processing and hence will need all the rows.

This fix is backported from 5.6. This problem is fixed in 5.6 as   
part of changes for work log #5558

RBR AND RC

Description: When scanning and locking rows with < or <=, InnoDB locks
the next row even though row based binary logging and read committed
is used.

Solution: In the handler, when the row is identified to fall outside
of the range (as specified in the query predicates), then request the
storage engine to unlock the row (if possible). This is done in
handler::read_range_first() and handler::read_range_next().

No commit message

Problem:
=======
The return value from my_b_write is ignored by: `my_b_write_quoted',
`my_b_write_bit',`Query_log_event::print_query_header'

Most callers of `my_b_printf' ignore the return value. `log_event.cc' 
has many calls to it. 

Analysis:
========
`my_b_write' is used to write data into a file. If the write fails it
sets appropriate error number and error message through my_error()
function call and sets the IO_CACHE::error == -1.
`my_b_printf' function is also used to write data into a file, it
internally invokes my_b_write to do the write operation. Upon
success it returns number of characters written to file and on error
it returns -1 and sets the error through my_error() and also sets
IO_CACHE::error == -1.  Most of the event specific print functions
for example `Create_file_log_event::print', `Execute_load_log_event::print'
etc are the ones which make several calls to the above two functions and
they do not check for the return value after the 'print' call. All the above 
mentioned abuse cases deal with the client side.

Fix:
===
As part of bug fix a check for IO_CACHE::error == -1 has been added at 
a very high level after the call to the 'print' function.  There are 
few more places where the return value of "my_b_write" is ignored
those are mentioned below.

+++ mysys/mf_iocache2.c    2012-06-04 07:03:15 +0000
@@ -430,7 +430,8 @@
           memset(buffz, '0', minimum_width - length2);
         else
           memset(buffz, ' ', minimum_width - length2);
-        my_b_write(info, buffz, minimum_width - length2);

+++ sql/log.cc	2012-06-08 09:04:46 +0000
@@ -2388,7 +2388,12 @@
     {
       end= strxmov(buff, "# administrator command: ", NullS);
       buff_len= (ulong) (end - buff);
-      my_b_write(&log_file, (uchar*) buff, buff_len);

At these places appropriate return value handlers have been added.