RPL_SEMI_SYNC_MASTER_ENABLED OFF.

Problem:
=======
If master is waiting for a reply from slave, at this time
set global rpl_semi_sync_master_enabled=OFF, the master
server will crash.

Analysis:
========
When master is waiting for a reply from slave, at this time
if semi sync is switched off on master, during switch off if
active transactions are present the transactions will be
cleared and "active_tranxs_" variable will be set to NULL.

When the waiting master connection finds that semi sync is
switched of it tries to access "active_tranxs_" without
checking if the transaction list exists or not. Accessing
NULL transaction list causes the crash.

Fix:
===
A check has been added to see a valid list exists before
accessing the "active_tranxs_".

plugin/semisync/semisync_master.cc:
  Added check for the existence of valid 'active_transx_'.

Tested with:
gcc (GCC) 4.8.1 20130603 (Red Hat 4.8.1-1)

clang version 3.1 (tags/RELEASE_31/final)
Target: x86_64-apple-darwin10.8.0

  
my_strnxfrm_win1250ch could write into dest[destlen]
i.e. write a byte to the past-the-end of dest.

test change only.

Removed --source include/not_windows_embedded.inc
which was added due to that bug.

disable testcase due to BUG#17446090

	       IT IS DONE IN-PLACE

With change buffer enabled, InnoDB doesn't write a transaction log
record when it merges a record from the insert buffer to an secondary
index page if the insertion is performed as an update-in-place.

Fixed by logging the 'update-in-place' operation on secondary index
pages.

Approved by Marko. rb#2429

                WITH MY_B_VPRINTF()
Issue         : In LP 64 machine max long value can be 20 digit
                decimal value. But in my_b_vprintf() the intermediate
                buffer storage used is 17 bytes length. This will lead to
                buffer overflow.
Solution      : Increased the buffer storage from 17 to 32 bytes.
                code is backported from 5.6


mysys/mf_iocache2.c:
  In function my_b_vprintf increased the size of local buff from 17 to
  32 bytes.

For queries like
update t1 set ... where <unique key> order by ... limit ...
we need to handle the fact that unique keys allow NULL
values, and hence can return more than one row.


sql/opt_range.cc:
  When the unique key has multiple key parts,
  check each key_part for nullability, rather than the first key part.
  (s/key->part ==/key_tree->part ==/)
  
  Also: revert the if() test, for better readability.

                WITH MY_B_VPRINTF()

[Merge from 5.1]

Postfix, suppress the new warning generated by the bug's fix.

Dump thread may encounter an error when reading events from the active binlog
file. However the errors may be temporary, so dump thread will try to read
the event again. But dump thread seeked to an wrong position, it caused some
events was sent twice.

To fix the bug, prev_pos is defined out the while loop and is set the correct
position after reading every event correctly.

This patch also make binlog_can_be_corrupted more accurate, only the binlogs
not closed normally are marked binlog_can_be_corrupted.

Finally, two warnings are added when dump threads encounter the temporary
errors.

 Reverted the changes to spec file to ignore mysqld_safe.pid file, updated the logic to get the correct count of PID files

Merging from 5.1 to 5.5

      
Reverting the patch. Because this change is not to me made for GA versions.

Reverting the patch. Because this change is not to me made for GA versions.

Do not call abs(INT_MIN) as the result is undefined.

Add missing initialization in lex_start()

              FILES SPECIFIED WITH THE BASEDIR OPTION

Reverting the patch. Because asked for second review.

               DO WHAT YOU EXPECT"

Fix info:
--------

Backport of the deprecation bug fix (WL#5265) for global variable
'THREAD_CONCURRENCY' from mysql-5.6 to mysql-5.5

Note: With this backport, certain additional deprecation warnings
      would be reported under error conditions while setting the
      global/session variables.

	       CONTAINING NULL

Problem:-
In MySQL, We can obtain the number of distinct expression
combinations that do not contain NULL by giving a list of 
expressions in COUNT(DISTINCT).
However rows with NULL values are
incorrectly included in the count when loose index scan is 
used.

Analysis:-
In case of loose index scan, we check whether the field is null or 
not and increase the count in Item_sum_count::add().
But there we are checking for the first field in COUNT(DISTINCT), 
not for every field. This is causing an incorrect result.

Solution:-
Check all field in Item_sum_count::add(), whether there values 
are null or not. Then only increment the count.
******
Bug#17222452 - SELECT COUNT(DISTINCT A,B) INCORRECTLY COUNTS ROWS 
	       CONTAINING NULL

Problem:-
In MySQL, We can obtain the number of distinct expression
combinations that do not contain NULL by giving a list of 
expressions in COUNT(DISTINCT).
However rows with NULL values are
incorrectly included in the count when loose index scan is 
used.

Analysis:-
In case of loose index scan, we check whether the field is null or 
not and increase the count in Item_sum_count::add().
But there we are checking for the first field in COUNT(DISTINCT), 
not for every field. This is causing an incorrect result.

Solution:-
Check all field in Item_sum_count::add(), whether there values 
are null or not. Then only increment the count.

              SPECIFIED WITH THE BASEDIR OPTION

Description: The mysql_plugin client attempts to remove any
filename specified to the --basedir option. The problem is 
that if the filename does not end with a slash, it will 
attempt to unlink it, which succeeds for files, but not for 
directories.

Analysis: When we are starting mysql_plugin with basedir 
option and if we are giving path of a file as basedir, it 
deletes that file. It was because it uses a function 
my_delete which unlinks the file path given.

Fix:  As a fix we replace that line using another function 
my_free, which will only free the  pointer which is having 
that file path.

No commit message

Memory Leak in mysql_options() was caused by missing call
to my_free() in MYSQL_SET_CLIENT_IP branch. Fixed by adding
my_free() to cleanup mysql->options.client_ip value before
assigning new value.

Memory Leak in mysql_options() was caused by missing call
to my_free() in MYSQL_SET_CLIENT_IP branch. Fixed by adding
my_free() to cleanup mysql->options.client_ip value before
assigning new value.