- Fix for MySQL BUG#52357 added NESTED_JOIN::is_fully_covered() which would
not take into account that MariaDB's table elimination could eliminate tables
from join plan (and so, from join nest).
Fixed the check in the function to compare post-table-elimination numbers.
- Added test case for Aria
- Tested HANDLER with HEAP (changes to HEAP code will be pushed in 5.3)
- Moved all HANDLER test to suite/handler.
mysql-test/Makefile.am:
Added suite/handler
mysql-test/mysql-test-run.pl:
Added suite/handler
mysql-test/r/lock_multi.result:
Remove test that is already in handler test suite
mysql-test/suite/handler/aria.result:
Test for HANDLER with Aria storage engine
mysql-test/suite/handler/aria.test:
Test for HANDLER with Aria storage engine
mysql-test/suite/handler/handler.inc:
Extended the general handler test
Moved interface testing to 'interface.test'
mysql-test/suite/handler/init.inc:
Common init for handler tests.
mysql-test/suite/handler/innodb.result:
New results
mysql-test/suite/handler/innodb.test:
Update to use new include files
mysql-test/suite/handler/interface.result:
Test of HANDLER interface (not storage engine dependent parts)
mysql-test/suite/handler/interface.test:
Test of HANDLER interface (not storage engine dependent parts)
mysql-test/suite/handler/myisam.result:
New results
mysql-test/suite/handler/myisam.test:
Update to use new include files
mysql-test/t/lock_multi.test:
Remove test that is already in handler test suite
mysys/tree.c:
Added missing handling of read previous (showed up in HEAP testing)
sql/handler.cc:
Don't marka 'HA_ERR_RECORD_CHANGED' as fatal (can be used with HANDLER READ, especially with MEMORY ENGINE)
sql/handler.h:
Added prototype for can_continue_handler_scan()
sql/sql_handler.cc:
Re-initialize search if we switch from key to table search.
Check if handler can continue searching between calls (via can_continue_handler_scan())
Don't write common not fatal errors to log
storage/maria/ma_extra.c:
Don't set index 0 as default. This forces call to ma_check_index() to set up index variables.
storage/maria/ma_ft_boolean_search.c:
Ensure that info->last_key.keyinfo is set
storage/maria/ma_open.c:
Don't set index 0 as default. This forces call to ma_check_index() to set up index variables.
storage/maria/ma_rkey.c:
Trivial optimization
storage/maria/ma_rnext.c:
Added missing code from mi_rnext.c to ensure that handler next/prev works.
storage/maria/ma_rsame.c:
Simple optimizations
storage/maria/ma_search.c:
Initialize info->last_key once and for all when we change keys.
storage/maria/ma_unique.c:
Ensure that info->last_key.keyinfo is up to date.
When the optimizer creates items out of other items it does
not have to call the fix_fields method. Usually in these
cases it calls quick_fix_field() that just marks the
created item as fixed. If the created item is an Item_func
object then calling quick_fix_field() works fine if the
arguments of the created functional item are already fixed.
Otherwise some unfixed nodes remain in the item tree and
it triggers an assertion failure whenever the item is
evaluated.
Fixed the problem by making the method quick_fix_field
virtual and providing an implementation for the class
Item_func objects that recursively calls the method
for unfixed arguments of any functional item.
Made archive.test a bit more safe
mysql-test/r/archive.result:
Added removal of files to make rerun of failed test work
mysql-test/t/archive.test:
Added removal of files to make rerun of failed test work
mysys/thr_lock.c:
Better warning message if lock test fails
Problem is that these tests run with --innodb-lock-wait-timeout=2 in .opt
(and this is necessary as built-in innodb does not allow to change this
dynamically). This cases another part of the test to occasionally time
out an UPDATE, which subsequently caused the test case to timeout due to
waiting for a condition (successful UPDATE) that never occurs.
Fixed by re-trying the update in case of timeout.
Tested by inserting a sleep() in the connection that the UPDATE is waiting
for, and checking that the retry loops a couple of times until the other
connection is done and COMMITs.
Open issues:
- A better fix for #57688; Igor is working on this
- Test failure in index_merge_innodb.test ; Igor promised to look at this
- Some Innodb tests fails (need to merge with latest xtradb) ; Kristian promised to look at this.
- Failing tests: innodb_plugin.innodb_bug56143 innodb_plugin.innodb_bug56632 innodb_plugin.innodb_bug56680 innodb_plugin.innodb_bug57255
- Werror is disabled; Should be enabled after merge with xtradb.
Registration of pointer change if we assign it to other pointer which should be identical after statement execution (PS/SP).
mysql-test/r/subselect.result:
Test suite.
mysql-test/t/subselect.test:
Test suite.
sql/sql_class.cc:
The procedure of the pointer registration.
sql/sql_class.h:
The procedure of the pointer registration.
sql/sql_lex.cc:
Registration of pointer change if we assign it to other pointer which should be identical after statement execution (PS/SP).
Implement os_event_wait_time() for POSIX systems.
In the purge thread, use os_event_wait_time() when sleeping rather than sleep,
and signal the event when server shuts down, so we do not need to wait for
upto 10 seconds until the purge thread wakes up.
Also fix bug that warnings that were pushed after we call set_ok_status() were
not included in the waning count sent to the client in the result packet.
Also in mysqltest, in recursive die() invocation at least print the message
before aborting.
client/mysqltest.cc:
If we detect recursive die(), at least print the message before aborting.
mysql-test/r/warnings_debug.result:
Test case.
mysql-test/t/warnings_debug.test:
Test case.
sql/handler.cc:
Force generation of a warning with specific debug option, for testing.
sql/protocol.cc:
Fix wrong DBUG_ENTER
sql/sql_class.h:
Add method to count warnings pushed after set_ok_status() is called.
sql/sql_error.cc:
Also count warnings pushed after set_ok_status() is called.
storage/xtradb/include/os0sync.h:
Implement working os_sync_wait_time() for POSIX.
storage/xtradb/include/srv0srv.h:
Make the purge thread wait for an event when sleeping, so we can signal it to
wakeup immediately at shutdown.
storage/xtradb/log/log0log.c:
Make the purge thread wait for an event when sleeping, so we can signal it to
wakeup immediately at shutdown.
storage/xtradb/os/os0sync.c:
Implement working os_sync_wait_time() for POSIX.
storage/xtradb/srv/srv0srv.c:
Make the purge thread wait for an event when sleeping, so we can signal it to
wakeup immediately at shutdown.
Added locking of lock mutex when updating status in external_unlock() for Aria and MyISAM tables.
Fixed that 'source' command doesn't cause mysql command line tool to exit on error.
DEBUG_EXECUTE() and DEBUG_EVALUATE_IF() should not execute things based on wildcards. (Allows one to run --debug with mysql-test-run scripts that uses @debug)
Fixed several core dump, deadlock and crashed table bugs in handling of LOCK TABLE with MERGE tables:
- Added priority of locks to avoid crashes with MERGE tables.
- Added thr_lock_merge() to allow one to merge two results of thr_lock().
Fixed 'not found row' bug in REPLACE with Aria tables.
Mark MyISAM tables that are part of MERGE with HA_OPEN_MERGE_TABLE and set the locks to have priority THR_LOCK_MERGE_PRIV.
- By sorting MERGE tables last in thr_multi_unlock() it's safer to release and relock them many times (can happen when TRIGGERS are created)
Avoid printing (null) in debug file (to easier find out wrong NULL pointer usage with %s).
client/mysql.cc:
Fixed that 'source' command doesn't cause mysql command line tool to exit on error.
client/mysqltest.cc:
Don't send NULL to fn_format(). (Can cause crash on Solaris when using --debug)
dbug/dbug.c:
DEBUG_EXECUTE() and DEBUG_EVALUATE_IF() should not execute things based on wildcards.
include/my_base.h:
Added flag to signal if one opens a MERGE table.
Added extra() command to signal that one is not part of a MERGE table anymore.
include/thr_lock.h:
Added priority for locks (needed to fix bug in thr_lock when using MERGE tables)
Added option to thr_unlock() if get_status() should be called.
Added prototype for thr_merge_locks().
mysql-test/mysql-test-run.pl:
Ignore crashed table warnings for tables named 'crashed'.
mysql-test/r/merge.result:
Renamed triggers to make debugging easier.
Added some CHECK TABLES to catch errors earlier.
Additional tests.
mysql-test/r/merge_debug.result:
Test of error handling when reopening MERGE tables.
mysql-test/r/udf_query_cache.result:
Added missing flush status
mysql-test/suite/parts/r/partition_repair_myisam.result:
Update results
mysql-test/t/merge.test:
Renamed triggers to make debugging easier.
Added some CHECK TABLES to catch errors earlier.
Additional tests.
mysql-test/t/merge_debug.test:
Test of error handling when reopening MERGE tables.
mysql-test/t/udf_query_cache.test:
Added missing flush status
mysys/my_getopt.c:
Removed not used variable
mysys/my_symlink2.c:
Changed (null) to (NULL) to make it easier to find NULL arguments to DBUG_PRINT() functions.
(On linux, NULL to sprintf is printed 'null')
mysys/thr_lock.c:
Added priority of locks to avoid crashes with MERGE tables.
Added thr_lock_merge() to allow one to merge two results of thr_lock().
- This is needed for MyISAM as all locked table must share the same status. If not, you will not see newly inserted rows in other instances of the table.
If calling thr_unlock() with THR_UNLOCK_UPDATE_STATUS, call update_status() and restore_status() for the locks. This is needed in some rare cases where we call thr_unlock() followed by thr_lock() without calling external_unlock/external_lock in between.
Simplify loop in thr_multi_lock().
Added 'start_trans', which is called at end of thr_multi_lock() when all locks are taken.
- This was needed by Aria to ensure that transaction is started when we got all locks, not at get_status(). Without this, some rows could not be visible when we lock two tables at the same time, causing REPLACE using two tables to fail unexpectedly.
sql/handler.cc:
Add an assert() in handler::print_error() for "impossible errors" (like table is crashed) when --debug-assert-if-crashed-table is used.
sql/lock.cc:
Simplify mysql_lock_tables() code if get_lock_data() returns 0 locks.
Added new parameter to thr_multi_unlock()
In mysql_unlock_read_tables(), call first externa_unlock(), then thr_multi_unlock(); This is same order as we do in mysql_unlock_tables().
Don't abort locks in mysql_lock_abort() for merged tables when a MERGE table is deleted; Would cause a spin lock.
Added call to thr_merge_locks() in mysql_lock_merge() to ensure consistency in thr_locks().
- New locks of same type and table is stored after the old lock to ensure that we get the status from the original lock.
sql/mysql_priv.h:
Added debug_assert_if_crashed_table
sql/mysqld.cc:
Added --debug-assert-if-crashed-table
sql/parse_file.cc:
Don't print '(null)' in DBUG_PRINT of no dir given
sql/set_var.cc:
Increase default size of buffer for @debug variable.
sql/sql_base.cc:
In case of error from reopen_table() in reopen_tables(), call unlock_open_table() and restart loop.
- This fixed bug when we twice deleted same table from open_cache.
Don't take name lock for already name locked table in open_unireg_entry().
- Fixed bug when doing repair in reopen_table().
- In detach_merge_children(), always detach if 'clear_refs' is given. We can't trust parent->children_attached as this function can be called twice, first time with clear_refs set to 0.
sql/sql_class.cc:
Changed printing of (null) to "" in set_thd_proc_info()
sql/sql_parse.cc:
Added DBUG
sql/sql_trigger.cc:
Don't call unlink_open_table() if reopen_table() fails as the table may already be freed.
storage/maria/ma_bitmap.c:
Fixed DBUG_ASSERT() in allocate_tail()
storage/maria/ma_blockrec.c:
Fixed wrong calculation of row length for very small rows in undo_row_update().
- Fixes ASSERT() when doing undo.
storage/maria/ma_blockrec.h:
Added _ma_block_start_trans() and _ma_block_start_trans_no_versioning()
storage/maria/ma_locking.c:
Call _ma_update_status_with_lock() when releasing write locks.
- Fixes potential problem with updating status without the proper lock.
storage/maria/ma_open.c:
Changed to use start_trans() instead of get_status() to ensure that we see all rows in all locked tables when we got the locks.
- Fixed 'not found row' bug in REPLACE with Aria tables.
storage/maria/ma_state.c:
Added _ma_update_status_with_lock() and _ma_block_start_trans().
This is to ensure that we see all rows in all locked tables when we got the locks.
storage/maria/ma_state.h:
Added _ma_update_status_with_lock()
storage/maria/ma_write.c:
More DBUG_PRINT
storage/myisam/mi_check.c:
Fixed error message
storage/myisam/mi_extra.c:
Added HA_EXTRA_DETACH_CHILD:
- Detach MyISAM table to not be part of MERGE table (remove flag & lock priority).
storage/myisam/mi_locking.c:
Call mi_update_status_with_lock() when releasing write locks.
- Fixes potential problem with updating status without the proper lock.
Change to use new HA_OPEN_MERGE_TABLE flag to test if MERGE table.
Added mi_fix_status(), called by thr_merge().
storage/myisam/mi_open.c:
Added marker if part of MERGE table.
Call mi_fix_status() in thr_lock() for transactional tables.
storage/myisam/myisamdef.h:
Change my_once_flag to uint, as it stored different values than just 0/1
Added 'open_flag' to store state given to mi_open()
storage/myisammrg/ha_myisammrg.cc:
Add THR_LOCK_MERGE_PRIV to THR_LOCK_DATA to get MERGE locks sorted after other types of locks.
storage/myisammrg/myrg_locking.c:
Remove windows specific code.
storage/myisammrg/myrg_open.c:
Use HA_OPEN_MERGE_TABLE to mi_open().
Set HA_OPEN_MERGE_TABLE for linked MyISAM tables.
storage/xtradb/buf/buf0buf.c:
Fixed compiler warning
storage/xtradb/buf/buf0lru.c:
Initialize variable that could be used not initialized.
Lines below which were added in the patch for Bug#56814 cause this crash:
+ if (table->table)
+ table->table->maybe_null= FALSE;
Consider following test case:
--
CREATE TABLE t1(f1 INT NOT NULL);
INSERT INTO t1 VALUES (16777214),(0);
SELECT COUNT(*) FROM t1 LEFT JOIN t1 t2
ON 1 WHERE t2.f1 > 1 GROUP BY t2.f1;
DROP TABLE t1;
--
We set TABLE::maybe_null to FALSE for t2 table
and in create_tmp_field() we create appropriate tmp table field
using create_tmp_field_from_item() function instead of
create_tmp_field_from_field. As a result we have
LONGLONG field. As we have GROUP BY clause we calculate
group buffer length, see calc_group_buffer().
Item from group list which is used for calculation
refer to the field from real tables and have LONG type.
So group buffer length become insufficient for storing of
LONGLONG value. It leads to overwriting of wrong memory
area in do_field_int() function which is called from
end_update().
After some investigation I found out that
create_tmp_field_from_item() is used only for OLAP
grouping and can not be used for common grouping
as it could be an incompatibility between tmp
table fields and group buffer length.
We can not remove create_tmp_field_from_item() call from
create_tmp_field as OLAP needs it and we can not use this
function for common grouping. So we should remove setting
TABLE::maybe_null to FALSE from simplify_joins().
In this case we'll get wrong behaviour of
list_contains_unique_index() back. To fix it we
could use Field::real_maybe_null() check instead of
Field::maybe_null() and add addition check of
TABLE_LIST::outer_join.
mysql-test/r/group_by.result:
test case
mysql-test/r/join_outer.result:
test case
mysql-test/t/group_by.test:
test case
mysql-test/t/join_outer.test:
test case
sql/sql_select.cc:
--remove wrong code
--use Field::real_maybe_null() check instead of
Field::maybe_null() and add addition check of
TABLE_LIST::outer_join
The problem is caused by bug49487 fix and became visible
after after bug56679 fix.
Items are cleaned up and set to unfixed state after filling derived table.
So we can not rely on item::fixed state in Item_func_group_concat::print
and we can not use 'args' array as items there may be cleaned up.
The fix is always to use orig_args array of items as it
always should contain the correct data.
mysql-test/r/func_gconcat.result:
test case
mysql-test/t/func_gconcat.test:
test case
sql/item_sum.cc:
The fix is always to use orig_args array of items.
The problem is dividing by const value when
the result is out of supported range.
The fix:
-return LONGLONG_MIN if the result is out of supported range for DIV operator.
-return 0 if divisor is -1 for MOD operator.
mysql-test/r/func_math.result:
test case
mysql-test/t/func_math.test:
test case
sql/item_func.cc:
-return LONGLONG_MIN if the result is out of supported range for DIV operator.
-return 0 if divisor is -1 for MOD operator.
The main.ps_ddl test does SELECT * FROM mysql.general_log; that can be really
expensive with --valgrind if previous test cases put lots of data in the
general log since last server restart. Fix by truncating the log at test start.
data dictionary confusion
On file systems with case insensitive file names, and
lower_case_table_names set to '2', the server could crash
due to a table definition cache inconsistency. This is
the default setting on MacOSX, but may also be set and
used on MS Windows.
The bug is caused by using two different strategies for
creating the hash key for the table definition cache, resulting
in failure to look up an entry which is present in the cache,
or failure to delete an existing entry. One strategy was to
use the real table name (with case preserved), and the other
to use a normalized table name (i.e a lower case version).
This is manifested in two cases. One is during 'DROP DATABASE',
where all known files are removed. The removal from
the table definition cache is done via a generated list of
TABLE_LIST with keys (wrongly) created using the case preserved
name. The other is during CREATE TABLE, where the cache lookup
is also (wrongly) based on the case preserved name.
The fix was to use only the normalized table name when
creating hash keys.
sql/sql_db.cc:
Normalize table name (i.e lower case it)
sql/sql_table.cc:
table_name contains the normalized name
alias contains the real table name
create_sort_index() function overwrites original JOIN_TAB::type field.
At re-execution of subquery overwritten JOIN_TAB::type(JT_ALL) is
used instead of JT_FT. It misleads test_if_skip_sort_order() and
the function tries to find suitable key for the order that should
not be allowed for FULLTEXT(JT_FT) table.
The fix is to restore JOIN_TAB strucures for subselect on re-execution
for EXPLAIN.
Additional fix:
Update TABLE::maybe_null field which
affects list_contains_unique_index() behaviour as it
could have the value(maybe_null==TRUE) based on the
assumption that this join is outer
(see setup_table_map() func).
mysql-test/r/explain.result:
test case
mysql-test/t/explain.test:
test case
sql/item_subselect.cc:
Make subquery uncacheable in case of EXPLAIN. It allows to keep
original JOIN_TAB::type(see JOIN::save_join_tab) and restore it
on re-execution.
sql/sql_select.cc:
-restore JOIN_TAB strucures for subselect on re-execution for EXPLAIN
-Update TABLE::maybe_null field as it could have
the value(maybe_null==TRUE) based on the assumption
that this join is outer(see setup_table_map() func).
This change is not related to the crash problem but
affects EXPLAIN results in the test case.
Subquery executes twice, at top level JOIN::optimize and ::execute stages.
At first execution create_sort_index() function is called and
FT_SELECT object is created and destroyed. HANDLER::ft_handler is cleaned up
in the object destructor and at second execution FT_SELECT::get_next() method
returns error.
The fix is to reinit HANDLER::ft_handler field before re-execution of subquery.
mysql-test/r/fulltext.result:
test case
mysql-test/t/fulltext.test:
test case
sql/item_func.cc:
reinit ft_handler before re-execution of subquery
sql/item_func.h:
Fixed method name
sql/sql_select.cc:
reinit ft_handler before re-execution of subquery
mysql-test/r/grant.result:
It was added result for test case for bug#36742.
mysql-test/t/grant.test:
It was added test case for bug#36742.
sql/sql_yacc.yy:
It was added convertation of host name part of user name to lowercase.
Problem: some call of INET_NTOA() function may lead
to a crash due to missing its character set initialization.
Fix: explicitly set the character set.
mysql-test/r/func_misc.result:
Fix for bug#57283: inet_ntoa() crashes
- test result.
mysql-test/t/func_misc.test:
Fix for bug#57283: inet_ntoa() crashes
- test case.
sql/item_strfunc.cc:
Fix for bug#57283: inet_ntoa() crashes
- explicitly set buffer's character set.
Problem: if multibyte and binary string arguments passed to
RPAD(), LPAD() or INSERT() functions, they might return
wrong results or even lead to a server crash due to missed
character set convertion.
Fix: perform the convertion if necessary.
mysql-test/r/ctype_utf8.result:
Fix for bug#57272: crash in rpad() when using utf8
- test result.
mysql-test/t/ctype_utf8.test:
Fix for bug#57272: crash in rpad() when using utf8
- test case.
sql/item_strfunc.cc:
Fix for bug#57272: crash in rpad() when using utf8
- convert multibyte argument's character set to binary in case of
FUNCTION(MULTIBYTE_ARG, .., BINARY_ARG,..) for RPAD(), LPAD() and
INSERT() functions.
This is a regression from the fix for bug no 38999. A storage engine capable
of reading only a subset of a table's columns updates corresponding bits in
the read buffer to signal that it has read NULL values for the corresponding
columns. It cannot, and should not, update any other bits. Bug no 38999
occurred because the implementation of UPDATE statements compare the NULL bits
using memcmp, inadvertently comparing bits that were never requested from the
storage engine. The regression was caused by the storage engine trying to
alleviate the situation by writing to all NULL bits, even those that it had no
knowledge of. This has devastating effects for the index merge algorithm,
which relies on all NULL bits, except those explicitly requested, being left
unchanged.
The fix reverts the fix for bug no 38999 in both InnoDB and InnoDB plugin and
changes the server's method of comparing records. For engines that always read
entire rows, we proceed as usual. For engines capable of reading only select
columns, the record buffers are now compared on a column by column basis. An
assertion was also added so that non comparable buffers are never read. Some
relevant copy-pasted code was also consolidated in a new function.
LOAD DATA into partitioned MyISAM table
Problem was that both partitioning and myisam
used the same table_share->mutex for different protections
(auto inc and repair).
Solved by adding a specific mutex for the partitioning
auto_increment.
Also adding destroying the ha_data structure in
free_table_share (which is to be propagated
into 5.5).
This is a 5.1 ONLY patch, already fixed in 5.5+.
The crash happens because original join table is replaced with temporary table
at execution stage and later we attempt to use this temporary table in
select_describe. It might happen that
Item_subselect::update_used_tables() method which sets const_item flag
is not called by some reasons (no where/having conditon in subquery for example).
It prevents JOIN::join_tmp creation and breaks original join.
The fix is to call ::update_used_tables() before ::const_item() check.
mysql-test/r/ps.result:
test case
mysql-test/t/ps.test:
test case
sql/item_subselect.cc:
call ::update_used_tables() before ::const_item() check.
Bug#57113: ha_partition::extra(ha_extra_function):
Assertion `m_extra_cache' failed
Fix for bug#55458 included DBUG_ASSERTS causing
debug builds of the server to crash on
another multi-table update.
Removed the asserts since they where wrong.
(updated after testing the patch in 5.5).
mysql-test/r/partition.result:
updated result
mysql-test/t/partition.test:
Added test for bug#57113
sql/ha_partition.cc:
Removed the assert for m_extra_cache when
::extra(HA_PREPARE_FOR_UPDATE) was called.
The condition over the outer tables now are extracted from
the on condition of any outer join. This condition is
saved in a special field of the JOIN_TAB structure for
the first inner table of the outer join. The condition
is checked before the first inner table is accessed. If
it turns out to be false the table is not accessed at all
and a null complemented row is generated immediately.
In case of outer join and emtpy WHERE conditon
'always true' condition is created for WHERE clasue.
Later in mysql_select() original SELECT_LEX WHERE
condition is overwritten with created cond.
However SELECT_LEX condition is also used as inital
condition in mysql_select()->JOIN::prepare().
On second execution of PS modified SELECT_LEX condition
is taken and it leads to crash.
The fix is to restore original SELECT_LEX condition
(set to NULL if original cond is NULL) in
reinit_stmt_before_use().
HAVING clause is fixed too for safety reason
(no test case as I did not manage to think out
appropriate example).
mysql-test/r/ps.result:
test case
mysql-test/t/ps.test:
test case
sql/sql_prepare.cc:
restore original SELECT_LEX condition
(set to NULL if original cond is NULL) in
reinit_stmt_before_use()
Fixed a number of memory leaks discovered by valgrind.
dbug/dbug.c:
This is actually an addendum to the fix for bug #52629:
- there is no point in limiting the fix to just global
variables, session ones are also affected.
- zero all fields when allocating a new 'state' structure so
that FreeState() does not deal with unitialized data later.
- add a check for a NULL pointer in DBUGCloseFile()
mysql-test/r/partition_error.result:
Added a test case for bug #56709.
mysql-test/r/variables_debug.result:
Added a test case for bug #56709.
mysql-test/t/partition_error.test:
Added a test case for bug #56709.
mysql-test/t/variables_debug.test:
Added a test case for bug #56709.
sql/item_timefunc.cc:
There is no point in declaring 'value' as a member of
Item_extract and dynamically allocating memory for it in
Item_extract::fix_length_and_dec(), since this string is only
used as a temporary storage in Item_extract::val_int().
sql/item_timefunc.h:
Removed 'value' from the Item_extract class definition.
sql/sql_load.cc:
- we may need to deallocate 'buffer' even when 'error' is
non-zero in some cases, since 'error' is public, and there is
external code modifying it.
- assign NULL to buffer when deallocating it so that we don't
do it twice in the destructor
- there is no point in changing 'error' in the destructor.