Problem: storing "SELECT ... INTO @var ..." results in variables we used val_xxx()
methods which returned results of the current row. 
So, in some cases (e.g. SELECT DISTINCT, GROUP BY or HAVING) we got data
from the first row of a new group (where we evaluate a clause) instead of
data from the last row of the previous group.

Fix: use val_xxx_result() counterparts to get proper results.


mysql-test/r/distinct.result:
  Fix for bug#42009: SELECT into variable gives different results to direct SELECT
    - results adjusted.
mysql-test/r/user_var.result:
  Fix for bug#42009: SELECT into variable gives different results to direct SELECT
    - test result.
mysql-test/t/user_var.test:
  Fix for bug#42009: SELECT into variable gives different results to direct SELECT
    - test case.
sql/item_func.cc:
  Fix for bug#42009: SELECT into variable gives different results to direct SELECT
    - Item_func_set_user_var::save_item_result() added to evaluate and store 
      an item's result into a user variable.
sql/item_func.h:
  Fix for bug#42009: SELECT into variable gives different results to direct SELECT
    - Item_func_set_user_var::save_item_result() added to evaluate and store 
      an item's result into a user variable.
sql/sql_class.cc:
  Fix for bug#42009: SELECT into variable gives different results to direct SELECT
    - use Item_func_set_user_var::save_item_result() to store results into user 
      variables.

  
The --hexdump option crashed mysqlbinlog when used together  
with the --read-from-remote-server option due to use of  
uninitialized memory.  
  
Since Log_event::print_header() relies on temp_buf to be  
initialized when the --hexdump option is present,  
dump_remote_log_entries() was fixed to setup temp_buf to point  
to the start of a binlog event as done in  
dump_local_log_entries().  
 
The root cause of this bug is identical to the one for 
bug #17654. The latter was fixed in 5.1 and up, so this 
patch is backport of the patches for bug #17654 to 5.0. 
 
Only 5.0 needs a changelog entry. 

client/mysqlbinlog.cc:
  Fixed dump_remote_log_entries() so that temp_buf is initialized 
  as it may be used later by Log_event::print_header() if the 
  --hexdump option is present.
mysql-test/r/mysqlbinlog.result:
  Added a test case for bug #41943.
mysql-test/t/mysqlbinlog.test:
  Added a test case for bug #41943.

         with seg fault

Multiple-table DELETE from a table joined to itself may cause
server crash. This was originally discovered with MEMORY engine,
but may affect other engines with different symptoms.

The problem was that the server violated SE API by performing
parallel table scan in one handler and removing records in
another (delete on the fly optimization).


mysql-test/r/heap_btree.result:
  Updated test result after adding new test for this bug.
mysql-test/t/heap_btree.test:
  Updated test result after adding new test for the bug report.
sql/sql_delete.cc:
  Updated to check if the files in delete list appears in join list and disable 
  delete while scanning, if it appears.

When a user selected an unsupported character set for an
IBMDB2I table, error 2501 or 2511 may have been returned,
giving the appearance of an internal programming error.

This patch consolidates these errors into a single descriptive
error message for the common case of an unsupported character
set.

The new error number is 2504 and indicates a user error.
The errors 2501 and 2511 remain to indicate cases of internal
programming errors.

storage/ibmdb2i/db2i_charsetSupport.cc:
  Bug#44232 Error msg should be improved when collation not supported.
          
  consolidate errors 2501 and 2511 into a single
  descriptive error message for the common case
  of an unsupported character set.
storage/ibmdb2i/db2i_conversion.cc:
  Bug#44232 Error msg should be improved when collation not supported.
          
  consolidate errors 2501 and 2511 into a single
  descriptive error message for the common case
  of an unsupported character set.
storage/ibmdb2i/db2i_errors.cc:
  Bug#44232 Error msg should be improved when collation not supported.
          
  consolidate errors 2501 and 2511 into a single
  descriptive error message for the common case
  of an unsupported character set.
storage/ibmdb2i/db2i_errors.h:
  Bug#44232 Error msg should be improved when collation not supported.
          
  consolidate errors 2501 and 2511 into a single
  descriptive error message for the common case
  of an unsupported character set.

on cp932 and sjis environment.
Problem: case conversion erroneously changes the second bytes
of multi-byte sequences because single-byte functions were
called in a mistake.
Fix: call multi-byte aware functions instead.

removed few sprintf's

'INSERT ... SELECT' statements

Merge

'INSERT ... SELECT' statements
            
The code that produces result rows expected that a duplicate row
error could not occur in INSERT ... SELECT statements with 
unfulfilled WHERE conditions. This may happen, however, if the 
SELECT list contains only aggregate functions.
Fixed by checking if an error occured before trying to send EOF
to the client.


mysql-test/r/insert_select.result:
  Bug#44306: Test result
mysql-test/t/insert_select.test:
  Bug#44306: Test case
sql/sql_select.cc:
  Bug#44306: Fix

A backport of fix for "BUG40092 - Storage engine API uses
time_t datatype".

Starting from MSVC C++ 2005 (v8), the default size of time_t
is changed from 32-bit to 64-bit. As the result, the binaries
built with pre-v8 MSVC C++ do not work with the binaries
(storage engine plugins) built with v8 or after (server
crashes).

Fixed storage engine API to use datatype with known size
(ulong) instead of time_t.

sql/handler.h:
  Bug#39802 On Windows, 32-bit time_t should be enforced
  
  Change create_time, check_time, update_time
  in the ha_statistics and PARTITION_INFO
  structures to ulong.

                               table corruption

Disabling the mysiam_debug.test in embedded mode because of BUG#43733

mysql-test/t/myisam_debug.test:
  Disable the test in embedded mode

1. Replace waiting of SQL thread stop by waiting of SQL error on slave and stopped
SQL thread.
2. Remove debug code because it already implemented in MTR2.

EXPLAIN EXTENDED of nested query containing a error:

   1054 Unknown column '...' in 'field list'

may cause a server crash.


Parse error like described above forces a call to
JOIN::destroy() on malformed subquery.
That JOIN::destroy function closes and frees temporary
tables. However, temporary fields of these tables
may be listed in st_select_lex::group_list of outer
query, and that st_select_lex may not cleanup them
properly. So, after the JOIN::destroy call that
st_select_lex::group_list may have Item_field
objects with dangling pointers to freed temporary
table Field objects. That caused a crash.


mysql-test/r/subselect3.result:
  Added test case for bug #37362.
mysql-test/t/subselect3.test:
  Added test case for bug #37362.
sql/sql_select.cc:
  Bug #37362: Crash in do_field_eq
  
  The JOIN::destroy function has been modified to
  cleanup temporary table column items.