SQL_SELECT::test_quick_select

The crash was caused by an incomplete cleanup of JOIN_TAB::select
during the filesort of rows for GROUP BY clause inside a subquery.
Queries where a quick index access is replaced with filesort was
was affected. For example:

  SELECT 1 FROM
    (SELECT COUNT(DISTINCT c1) FROM t1
       WHERE c2 IN (1, 1) AND c3 = 2 GROUP BY c2) x

Quick index access related data in the SQL_SELECT::test_quick_select
function was inconsistent after an incomplete cleanup.
This function has been completed to prevent crashes in the
SQL_SELECT::test_quick_select function.


mysql-test/include/mix1.inc:
  Add test case for bug #44290.
mysql-test/r/innodb_mysql.result:
  Add test case for bug #44290.
sql/sql_select.cc:
  Bug #44290: explain crashes for subquery with distinct in
              SQL_SELECT::test_quick_select
  
  Quick index access related data in the SQL_SELECT::test_quick_select
  function was inconsistent after an incomplete cleanup.
  This function has been completed to prevent crashes in the
  SQL_SELECT::test_quick_select function.

Problem: using LOAD_FILE() in some cases we pass a file name string
without a trailing '\0' to fn_format() which relies on that however.
That may lead to valgrind warnings.

Fix: add a trailing '\0' to the file name passed to fn_format().


mysql-test/r/func_str.result:
  Fix for bug#44774: load_file function produces valgrind warnings
    - test result.
mysql-test/t/func_str.test:
  Fix for bug#44774: load_file function produces valgrind warnings
    - test case.
sql/item_strfunc.cc:
  Fix for bug#44774: load_file function produces valgrind warnings
    - passing a file name to fn_format(), file_name->c_ptr() replaced
      with file_name->c_ptr_safe() to ensure we have a trailing '\0'.

      
In the output from mysqlbinlog, incident log events were
represented as just a comment. Since the incident log event
represents an incident that could cause the contents of the
database to change without being logged to the binary log,
it means that if the SQL is applied to a server, it could
potentially lead to that the databases are out of sync.

In order to handle that, this patch adds the statement "RELOAD
DATABASE" to the SQL output for the incident log event. This will
require a DBA to edit the file and handle the case as apropriate
before applying the output to a server.

mysql-test/suite/binlog/t/binlog_incident-master.opt:
  Options file to cause server to generate an incident log
  event when executing a REPLACE.
mysql-test/suite/binlog/t/binlog_incident.test:
  Test to check that the incident log event is represented
  correctly in the output from mysqlbinlog.
sql/log_event.cc:
  The incident log event now ouput a "RELOAD DATABASE" instead
  of just a comment. RELOAD DATABASE is not an existing command
  and will generate a syntax error.

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.

utility. (Bug #41883, patch by Nicklas Westerlund)

to an empty string, or to /dev/null, as we suggest and have suggested in the
documentation. (Bug #34224)

quote them in later use. (Bug #33685, based on a patch by Hartmut Holzgraefe)

backwards, which resulted in the incorrect time being reported at the
end of mysqldump. (Bug #44424, patch by Andrew Hutchings)

handle the --skip-password option correctly. (Bug #28479)

based on a contribution by Ask Bjørn Hansen)

which didn't actually do anything. (Bug #39101)

  
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.

patch contributed by Andrew Hutchings)

                        
Certain multi-updates gave different results on InnoDB from
to MyISAM, due to on-the-fly updates being used on the former and
the update order matters.
Fixed by turning off on-the-fly updates when update order 
dependencies are present.


mysql-test/r/innodb_mysql.result:
  Bug#43580: Test result.
mysql-test/suite/rpl/r/rpl_slave_skip.result:
  Bug#43580: Changed test result. The InnoDB result is now what it would have been on MyISAM.
mysql-test/t/innodb_mysql.test:
  Bug#43580: Test case.
sql/sql_base.cc:
  Bug#43580: Added a word of caution about using tmp_set here.
sql/sql_update.cc:
  Bug#43580: Fix.
  Calls to TABLE::mark_columns_needed_for_update() are moved
  from mysql_multi_update_prepare() and right before the decison
  to do on-the-fly updates to the place where we do (or don't do)
  on-the-fly updates.