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At logging a first Query referring a user var, the slave missed to log the user var.
It appears that at execution of a Uservar event the slaver applier
thought of the variable as already logged.
The reason of misjudgement is in coincidence of query id:s: of one that the thread
holds at Uservar execution and another one that the thread sees at the Query applying.
While the two are naturally different in the regular execution branch (as two computational
events are separated as individual events), in the deferred applying case the User var execution
effectively belongs to its Query processing.

Fixed with storing the Uservar parsing time (where desicion to defer is taken) query id 
to temporarily substitute with it the actual query id at the Uservar execution time
(along with its query).
Such manipulation mimics behaviour of the regular applying branch.

sql/log_event.cc:
  Storing the Uservar parsing time query id into a new member of the event
  to to temporarily substitute
  with it the actual thread id at the Uservar execution time.
sql/log_event.h:
  Storage for keeping query-id in User-var intance is added.

Bug#13243248 CHECK FOR "STACK OVERRUN" DOESN'T WORK WITH GCC-4.6, SERVER CRASHES

The existing check for stack direction may give wrong results
for new versions of gcc at high optimization levels.

Solution: Backport the stack-direction check from 5.5

      
Problem - When the slave was disconnected from the master, under certain 
          conditions, upon reconnect, it will report that it received a 
          packet larger the slave_max_allowed_packet which causes the
          replication to stop.
 
Analysis -The reason of this failure is that on reconnect
          the slave sets the max_allowed_packet from the master's mi->mysql
          object which keeps the max_allowed_packet as 1MB. This causes the 
          slave to report such error on recieving packet bigger than 1MB. 
          START SLAVE on the slave fixes the problem since it restarts
          slave threads which initializes the max_allowed_packet to
          slave_max_allowed_packet.
      
Fix - The problem is fixed by some code refactoring and introduction of a new
      function which updates the max_allowed_packet for the THD object of the
      slave thread and the mysql->options max_allowed_packet.

As current size limit of 'url' field of help_topic
table is no longer sufficient for the contents of
the fill_help_tables-5.1.sql. So, loading the contents
in the table might result in warning (or error with
stricter modes).

Updated the type for 'url' field of help_topic as well
as help_category tables from char(128) to text.

(Based on Sinisa's patch)

Added a version checking facility to mysql_upgrade.
The versions used for checking is the version of the
server that mysql_upgrade is going to upgrade and the
server version that mysql_upgrade was build/distributed
with.
Also added an option '--version-check' to enable/disable
the version checking.

SHOW ENGINE INNOD

Problem:

The purpose of explain_filename() is to provide useful additional
information regarding the partitions given the filename.  This function
was returning an error when it was not able to parse the given filename.
For example, within InnoDB, temporary files are created with #sql-
prefix.  But this function was not able to parse it correctly.

Solution:

It is not an error, if explain_filename() could not parse the given
filename.  If there is no partition information to explain, then silently
return from the function.

rb#1940 approved by mattiasj

The range optimizer uses 'save_in_field_no_warnings()' to verify properties of
'value <cmp> field' expressions.
If this execution yields an error, it should abort.

              RETURNS RANDOM DATA
                 
MySQL 5.5 specific version of bugfix.
      
When Loose Index Scan Range access is used, MySQL execution needs
to copy non-aggregated fields. end_send() checked if this was
necessary by checking if join_tab->select->quick had type
QS_TYPE_GROUP_MIN_MAX.
      
In this bug, however, MySQL created a sort index to sort the rows
read from this range access method. create_sort_index() deletes
join_tab->select->quick which makes it impossible to inquire
the join_tab if LIS has been used.
      
The fix for MySQL 5.5 is to introduce a variable in JOIN_TAB
that stores whether or not LIS has been used. There is no need
for this variable in later MySQL versions because the relevant
code has been refactored.

Post push fix:
setup_ref_array() now uses n_sum_items to determine size of ref_pointer_array.
The problem was that n_sum_items kept growing, it wasn't reset for each query.

A similar memory leak was fixed with the patch for:
Bug 14683676 ENDLESS MEMORY CONSUMPTION IN SETUP_REF_ARRAY WITH MAX IN SUBQUERY


sql/sql_yacc.yy:
  Reset parsing_place when we're done parsing SHOW commands, 
  to prevent Item::Item incrementing select_n_having_items
  (which is also used in setup_ref_array())

UPDATES

After checking that the table has changed too much in
row_update_statistics_if_needed() and calling dict_update_statistics(),
also check if the same condition holds after acquiring the table stats
latch. This is to avoid multiple threads concurrently entering and
executing the stats update code.

Approved by:	Marko (rb:2186)

Problem:
=======
Found using AddressSanitizer testing.

The mysqlbinlog utility may result in out-of-bound heap
buffer reads and thus, undefined behaviour, when processing
RBR events in the old (pre-5.1 GA) format.

The following code in process_event() would only be correct
if Rows_log_event was the base class for
Write,Update,Delete_rows_log_event_old classes:

    case PRE_GA_WRITE_ROWS_EVENT:
    case PRE_GA_DELETE_ROWS_EVENT:
    case PRE_GA_UPDATE_ROWS_EVENT:
...
        Rows_log_event *e= (Rows_log_event*) ev;
        Table_map_log_event *ignored_map=
          print_event_info->m_table_map_ignored.get_table(e->get_table_id());
...
        if (e->get_flags(Rows_log_event::STMT_END_F))
        {
...
        }

However, Rows_log_event is only the base class for the
Write,Update_Delete_rows_event family of classes, but not
for their *_old counterparts. So the above typecasts are
incorrect for the old-format RBR events and may result (and
do result according to AddressSanitizer reports) in reading
memory outside of the previously allocated on heap buffer.

Fix:
===
The above mentioned invalid type cast has been replaced with
appropriate old counterpart.

Note:The above mentioned issue is present only mysql-5.1 and
5.5. This is fixed in mysql-5.6 and above as part of 
Bug#55790. Hence few of the relevant changes of Bug#55790 are
being back ported to fix the current issue.

client/mysqlbinlog.cc:
  The above mentioned invalid type cast of using new event
  object to read old events, has been replaced with
  appropriate old counterpart.
  
  Note:The above mentioned issue is present only mysql-5.1 and
  5.5. This is fixed in mysql-5.6 and above as part of 
  Bug#55790. Hence few of the relevant changes of Bug#55790 are
  being back ported to fix the current issue.

	
	Backport the changes for bug#14786792 which is regression 
	of fix for bug#11761854.So backported both changes.

  INTERACTIVE MODE

In interactive mode, libedit/readline allocates memory
for every new line entered & later the allocated memory
never gets freed.

Fixed by freeing the allocated memory blocks appropriately.

Null merge from mysql-5.1

Back porting fix from mysql-5.5

sql/rpl_utility.cc:
  Resetting last_added to NULL to avoid memory leak

We need to take 'n_sum_items' into the calculation
when allocating the ref_ptr_array.

Item_func_group_concat::copy_or_same() creates a copy of original object.
It also creates a copy of ORDER structure because ORDER struct elements may
be modified in find_order_in_list() called from Item_func_group_concat::setup().
As ORDER copy is created using memcpy, ORDER::next elements point to original
ORDER structs. Thus find_order_in_list() called from EXECUTE stmt modifies
ordinal ORDER item pointers so they point to runtime items, these items are
freed after execution, so original ORDER structure becomes invalid.
The fix is to properly update ORDER::next fields so that they point to
new ORDER elements.



sql/item_sum.cc:
  update ORDER::next fields so that they point to new ORDER elements.