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Commit Graph

20797 Commits

Author SHA1 Message Date
Sergey Glukhov
b41e2289ad 5.1-secutity->5.5-security merge(test case only) 2010-10-27 18:20:25 +04:00
Sergey Glukhov
c7371c9e75 Bug#57477 SIGFPE when dividing a huge number a negative number
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.
2010-10-27 18:12:10 +04:00
Georgi Kodinov
50d18aa2d5 merge 2010-10-27 09:32:26 +02:00
Alexander Nozdrin
e86b6c0db4 Patch for Bug#55850 (Trigger warnings not cleared).
The problem was that the warnings risen by a trigger were not cleared upon
successful completion. The warnings should be cleared if the trigger completes
successfully.

The fix is to skip merging warnings into caller's Warning Info for triggers.
2010-10-26 15:48:08 +04:00
Jon Olav Hauglid
b8a81fc6aa Merge from mysql-5.5-bugteam to mysql-5.5-runtime
No conflicts
2010-10-25 14:26:21 +02:00
Horst.Hunger
06a263e2b3 Due to failing on Freebsd. 2010-10-25 12:24:26 +02:00
Jon Olav Hauglid
1ecc17737f Merge from mysql-5.5-runtime to mysql-5.5-bugteam
No conflicts
2010-10-22 14:13:03 +02:00
Davi Arnaut
2881b8014c Bug#37780: Make KILL reliable (main.kill fails randomly)
- A prerequisite cleanup patch for making KILL reliable.

The test case main.kill did not work reliably.

The following problems have been identified:

1. A kill signal could go lost if it came in, short before a
thread went reading on the client connection.

2. A kill signal could go lost if it came in, short before a
thread went waiting on a condition variable.

These problems have been solved as follows. Please see also
added code comments for more details.

1. There is no safe way to detect, when a thread enters the
blocking state of a read(2) or recv(2) system call, where it
can be interrupted by a signal. Hence it is not possible to
wait for the right moment to send a kill signal. It has been
decided, not to fix it in the code.  Instead, the test case
repeats the KILL statement until the connection terminates.

2. Before waiting on a condition variable, we register it
together with a synchronizating mutex in THD::mysys_var. After
this, we need to test THD::killed again. At some places we did
only test it in a loop condition before the registration. When
THD::killed had been set between this test and the registration,
we entered waiting without noticing the killed flag. Additional
checks ahve been introduced where required.

In addition to the above, a re-write of the main.kill test
case has been done. All sleeps have been replaced by Debug
Sync Facility synchronization. A couple of sync points have
been added to the server code.

To avoid further problems, if the test case fails in spite of
the fixes, the test case has been added to the "experimental"
list for now.

- Most of the work on this patch is authored by Ingo Struewing


mysql-test/t/kill.test:
  Re-wrote test case to use Debug Sync points instead of sleeps
sql/event_queue.cc:
  Fixed kill detection in Event_queue::cond_wait() by adding a check
  after enter_cond().
sql/lock.cc:
  Moved Debug Sync points behind enter_cond().
  Fixed comments.
sql/slave.cc:
  Fixed kill detection in start_slave_thread() by adding a check
  after enter_cond().
sql/sql_class.cc:
  Swapped order of kill and close in THD::awake().
  Added comments.
sql/sql_class.h:
  Added a comment to THD::killed.
sql/sql_parse.cc:
  Added a sync point in do_command().
sql/sql_select.cc:
  Added a sync point in JOIN::optimize().
2010-10-22 09:58:09 -02:00
Horst.Hunger
d63cbdde8e Due to issues with merge. 2010-10-22 10:20:17 +02:00
Jon Olav Hauglid
a776e5f3d2 Merge from mysql-5.5-bugteam to mysql-5.5-runtime
No conflicts
2010-10-21 16:28:29 +02:00
Bjorn Munch
33e78dc233 merge from 5.5 2010-10-21 11:20:53 +02:00
Horst.Hunger
d6af9bef7a due to merge 2010-10-20 16:56:09 +02:00
Oystein Grovlen
7a8515cc20 Bug#57512 str_to_date crash...
str_to_date function should only try to generate a warning for
invalid input strings, not when input value is NULL. In latter
case, val_str() of input argument will return a nil pointer.
Trying to generate a warning using this pointer lead to a
segmentation fault. Solution: Only generate warning when pointer
to input string is non-nil.


mysql-test/r/func_time.result:
  Added test case for Bug#57512
mysql-test/t/func_time.test:
  Added test case for Bug#57512
sql/item_timefunc.cc:
  Skip generating warning when pointer to input string is nil
  since this implies that input argument was NULL.
2010-10-20 15:17:29 +02:00
Konstantin Osipov
08c5798839 Merge 5.5-bugteam -> 5.5-runtime. 2010-10-19 19:20:25 +04:00
Magne Mahre
95d91c0f57 Bug #46941 crash with lower_case_table_names=2 and foreign key
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
2010-10-19 12:27:09 +02:00
Jon Olav Hauglid
8f73bddc9a Merge from mysql-5.5-bugteam to mysql-5.5-runtime
No conflicts
2010-10-19 11:26:45 +02:00
Tor Didriksen
a6df37dbbf Bug #57203 Assertion `field_length <= 255' failed.
After the fix for
Bug #55077 Assertion failed: width > 0 && to != ((void *)0), file .\dtoa.c
we no longer try to allocate a string of length 'field_length'
so the asserts are relevant only for ZEROFILL columns.



mysql-test/r/select.result:
  Add test case for Bug#57203
mysql-test/t/select.test:
  Add test case for Bug#57203
sql/field.cc:
  Rewrite the DBUG_ASSERTS on field_length.
2010-10-19 08:45:18 +02:00
Magne Mahre
b61b785285 Merge from mysql-5.1-bugteam to mysql-5.5-bugteam
Only test case is merged, as the fix was already
present in 5.5 code
2010-10-19 12:29:21 +02:00
Dmitry Shulga
4053a5a448 Follow-up for bug#36742: changed results for test ipv4_as_ipv6 because hostname is case-insensitive. 2010-10-18 23:20:26 +07:00
Dmitry Shulga
1e2f4f68bd Auto-merge from mysql-5.1-bugteam for bug#36742. 2010-10-18 22:38:12 +07:00
Dmitry Shulga
cdddc7bfd5 Follow up for bug#36742. Changed test case for bug#19828
because currently hostname stored in db in lowercase.
2010-10-18 21:03:53 +07:00
Sergey Glukhov
babfc2e101 5.1-security->5.5-security merge 2010-10-18 16:22:02 +04:00
Sergey Glukhov
d0ac4e2c5a Bug#56814 Explain + subselect + fulltext crashes server
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.
2010-10-18 16:12:27 +04:00
Sergey Glukhov
318b590b0a 5.1-security->5.5-security merge 2010-10-18 15:06:15 +04:00
Sergey Glukhov
127c721cef Bug#54484 explain + prepared statement: crash and Got error -1 from storage engine
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
2010-10-18 14:47:26 +04:00
Alexey Botchkov
8760cec601 merging. 2010-10-15 20:13:35 +05:00
Mattias Jonsson
b86026dab5 Manual merge 2010-10-15 10:06:22 +02:00
Mattias Jonsson
2234783085 merge 2010-10-15 09:27:28 +02:00
Konstantin Osipov
248625d910 A fix and a test case for Bug#56540 "Exception (crash) in
sql_show.cc during rqg_info_schema test on Windows".

Ensure we do not access freed memory when filling
information_schema.views when one of the views
could not be properly opened.



mysql-test/r/information_schema.result:
  Update results - a fix for Bug#56540.
mysql-test/t/information_schema.test:
  Add a test case for Bug#56540
sql/sql_base.cc:
  Push an error into the Diagnostics area
  when we return an error.
  This directs get_all_tables() to the execution
  branch which doesn't involve 'process_table()'
  when no table/view was opened.
sql/sql_show.cc:
  Do not try to access underlying table fields
  when opening of a view failed. The underlying
  table is closed in that case, and accessing
  its fields may lead to dereferencing a damaged 
  pointer.
2010-10-14 20:56:56 +04:00
Jon Olav Hauglid
b5be2fbc8d Bug #55930 Assertion `thd->transaction.stmt.is_empty() ||
thd->in_sub_stmt || (thd->state..

OPTIMIZE TABLE is not directly supported by InnoDB. Instead,
recreate and analyze of the table is done. After recreate,
the table is closed and locks are released before the table
is reopened and locks re-acquired for the analyze phase.

This assertion was triggered if OPTIMIZE TABLE failed to
acquire thr_lock locks before starting the analyze phase.
The assertion tests (among other things) that there no
active statement transaction. However, as part of acquiring
the thr_lock lock, external_lock() is called for InnoDB
tables and this causes a statement transaction to be started.
If thr_multi_lock() later fails (e.g. due to timeout),
the failure handling code causes this assert to be triggered.

This patch fixes the problem by doing rollback of the
current statement transaction in case open_ltable (used by
OPTIMIZE TABLE) fails to acquire thr_lock locks.

Test case added to lock_sync.test.
2010-10-13 16:15:28 +02:00
Dmitry Shulga
333434d23b Auto-merge from mysql-5.1-bugteam for bug#36742. 2010-10-13 13:27:03 +07:00
Dmitry Shulga
8169faec27 Fixed bug#36742 - GRANT hostname case handling inconsistent.
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.
2010-10-13 12:28:58 +07:00
Ramil Kalimullin
dcf2373710 Merge. 2010-10-13 08:51:37 +04:00
Alexander Nozdrin
ba084605e8 Auto-merge from mysql-5.5-bugteam. 2010-10-13 01:17:22 +04:00
Ramil Kalimullin
b001a5224d Fix for bug#57283: inet_ntoa() crashes
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.
2010-10-12 23:28:03 +04:00
Ramil Kalimullin
42550e21e8 Fix for bug#57272: crash in rpad() when using utf8
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.
2010-10-12 23:25:40 +04:00
Dmitry Lenev
1af8cfa094 Merged recent changes from mysql-5.5-bugteam into
mysql-5.5-runtime tree.
2010-10-08 20:33:46 +04:00
Davi Arnaut
15ccca1d55 Bug#56822: Add a thread state for sessions waiting on the query cache lock
Only wait for a single debug signal at a time as the signal state
is global. Also, do not activate the query cache debug sync points
if the thread has no associated THD session.

mysql-test/t/query_cache_debug.test:
  Only wait for a single debug signal at a time as the signal state
  is global.
sql/sql_cache.cc:
  Do not execute the debug sync point if the thread has no associated
  THD session. This scenario happens for federated threads.
2010-10-08 09:16:20 -03:00
Tor Didriksen
c8d7a31f35 Bug#57209 valgrind + Assertion failed: dst > buf
Buffer overrun when trying to format DBL_MAX


mysql-test/r/func_math.result:
  Add test case for Bug#57209
mysql-test/t/func_math.test:
  Add test case for Bug#57209
sql/item_strfunc.cc:
  Allocate a larger buffer for the result.
2010-10-08 11:52:09 +02:00
Alexey Botchkov
42dc7264c0 Bug#35269 mysqlcheck behaves different depending on order of parameters
Issue an error if user specifies multiple commands to run.
        Also there was an unnoticed bug that DO_CHECK was actually 0 which lead
        to wrong actions in some cases.
        The mysqlcheck.test contained commands with the suspicious meaning
        for the above reason. Extra commands removed from there.

per-file commands:
  client/mysqlcheck.c
Bug#35269      mysqlcheck behaves different depending on order of parameters
        Drop with an error if multiple commands.
  mysql-test/r/mysqlcheck.result
Bug#35269      mysqlcheck behaves different depending on order of parameters
        result completed.
  mysql-test/t/mysqlcheck.test
Bug#35269      mysqlcheck behaves different depending on order of parameters
        testcase added.
        not-working commands removed from some mysqlcheck calls.
2010-10-08 12:09:47 +05:00
Davi Arnaut
36051b0106 Bug#56822: Add a thread state for sessions waiting on the query cache lock
The problem was that threads waiting on the query cache lock
are not easily seen due to the lack of a state indicating that
the thread is waiting on the said lock. This made it difficult
for users to quickly spot (for example, via SHOW PROCESSLIST)
a query cache contention problem.

The solution is to update the thread state when the query cache
lock needs to be acquired. Whenever the lock is to be acquired,
the thread state is updated to "Waiting for query cache lock"
and is reset once the lock is granted or the wait is interrupted.
The intention is to make query cache related hangs more evident.

To further investigate query cache related locking problems, one
may use PERFORMANCE_SCHEMA to track the overhead associated with
the locking bits and determine which particular lock is being a
contention point.

sql/sql_cache.cc:
  Set and reset the thread state whenever a attempt to lock the
  query cache is made.
  
  Use DEBUG_SYNC instead of the now unnecessary wait_for_kill hack.
2010-10-07 19:51:37 -03:00
Evgeny Potemkin
7365a389a3 Auto-merged. 2010-10-07 20:39:24 +04:00
Evgeny Potemkin
731dcfc7ff Bug#57095: Wrongly chosen expression cache type led to a wrong result.
The coalesce function returned DATETIME type due to a DATETIME argument, but
since it's not a date/time function it can't return correct int value for
it. Nevertheless Item_datetime_cache was chosen to cache coalesce's result
and that led to a wrong result.

Now Item_datetime_cache is used only for those function that could return
correct int representation of DATETIME values.


mysql-test/r/type_datetime.result:
  Added a test case for the bug#57095.
mysql-test/t/type_datetime.test:
  Added a test case for the bug#57095.
sql/item.cc:
  Bug#57095: Wrongly chosen expression cache type led to a wrong result.
  Now Item_datetime_cache is used only for those function that could return
  correct int representation of DATETIME values.
2010-10-07 20:16:30 +04:00
Dmitry Lenev
eaae675279 Fix for bug#57061 "User without privilege on routine can
discover its existence".

The problem was that user without any privileges on 
routine was able to find out whether it existed or not.
DROP FUNCTION and DROP PROCEDURE statements were 
checking if routine being dropped existed and reported 
ER_SP_DOES_NOT_EXIST error/warning before checking 
if user had enough privileges to drop it.

This patch solves this problem by changing code not to 
check if routine exists before checking if user has enough 
privileges to drop it. Moreover we no longer perform this 
check using a separate call instead we rely on 
sp_drop_routine() returning SP_KEY_NOT_FOUND if routine 
doesn't exist.

This change also simplifies one of upcoming patches
refactoring global read lock implementation.

mysql-test/r/grant.result:
  Updated test case after fixing bug#57061 "User without
  privilege on routine can discover its existence". Removed
  DROP PROCEDURE/FUNCTION statements which have started to
  fail after this fix (correctly). There is no need in
  dropping routines in freshly created database anyway.
mysql-test/r/sp-security.result:
  Added new test case for bug#57061 "User without privilege
  on routine can discover its existence". Updated existing
  tests according to new behaviour.
mysql-test/suite/funcs_1/r/innodb_storedproc_06.result:
  Updated test case after fixing bug#57061 "User without
  privilege on routine can discover its existence".
  Now we drop routines under user which has enough
  privileges to do so.
mysql-test/suite/funcs_1/r/memory_storedproc_06.result:
  Updated test case after fixing bug#57061 "User without
  privilege on routine can discover its existence".
  Now we drop routines under user which has enough
  privileges to do so.
mysql-test/suite/funcs_1/r/myisam_storedproc_06.result:
  Updated test case after fixing bug#57061 "User without
  privilege on routine can discover its existence".
  Now we drop routines under user which has enough
  privileges to do so.
mysql-test/suite/funcs_1/storedproc/storedproc_06.inc:
  Updated test case after fixing bug#57061 "User without
  privilege on routine can discover its existence".
  Now we drop routines under user which has enough
  privileges to do so.
mysql-test/t/grant.test:
  Updated test case after fixing bug#57061 "User without
  privilege on routine can discover its existence". Removed
  DROP PROCEDURE/FUNCTION statements which have started to
  fail after this fix (correctly). There is no need in
  dropping routines in freshly created database anyway.
mysql-test/t/sp-security.test:
  Added new test case for bug#57061 "User without privilege
  on routine can discover its existence". Updated existing
  tests according to new behaviour.
sql/sp.cc:
  Removed sp_routine_exists_in_table() which is no longer
  used.
sql/sp.h:
  Removed sp_routine_exists_in_table() which is no longer
  used.
sql/sql_parse.cc:
  When dropping routine we no longer check if routine exists 
  before checking if user has enough privileges to do so. 
  Moreover we no longer perform this check using a separate 
  call instead we rely on sp_drop_routine() returning 
  SP_KEY_NOT_FOUND if routine doesn't exist.
2010-10-07 20:01:17 +04:00
Sergey Vojtovich
85d023eb38 Merge WL#5496 and WL#5341 to 5.5-bugteam. 2010-10-07 19:52:34 +04:00
Jon Olav Hauglid
e486d21dfc Merge from mysql-5.5-runtime to mysql-5.5-bugteam
No conflicts
2010-10-07 14:12:33 +02:00
Martin Hansson
95f8d9a2a4 Bug#56423: Different count with SELECT and CREATE SELECT queries
This is the 5.5 version of the fix. The 5.1 version was too complicated to
merge and was null merged.

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.
2010-10-07 12:01:51 +02:00
Evgeny Potemkin
5dc76bfabf Auto-merged. 2010-10-07 12:17:08 +04:00
Martin Hansson
30f57b3323 Bug#56423: Different count with SELECT and CREATE SELECT queries
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.
2010-10-07 10:13:11 +02:00
Evgeny Potemkin
3c9c7efb3b Bug#57039: constant subtime expression returns incorrect result.
The subtime function wasn't able to produce correct int representation of
its result. For constant expressions the Item_datetime_cache is used to
speedup evaluation and Item_datetime_cache expects underlying item to return
correct int representation of DATETIME value. These two factors combined led
to a wrong query result.

Now the Item_func_add_time has function val_datetime which performs the
calculation and saves result into given MYSQL_TIME struct, it also sets
null_value to appropriate value. val_int and val_str member functions
convert the result obtained from val_datetime to int or string respectively
and returns it.

mysql-test/r/func_time.result:
  Added a test case for the bug#57039.
mysql-test/t/func_time.test:
  Added a test case for the bug#57039.
sql/item_timefunc.cc:
  Bug#57039: constant subtime expression returns incorrect result.
  Now the Item_func_add_time has function val_datetime which performs the
  calculation and saves result into given MYSQL_TIME struct, it also sets
  null_value to appropriate value. val_int and val_str member functions
  convert the result obtained from val_datetime to int or string respectively
  and returns it.
sql/item_timefunc.h:
  Bug#57039: constant subtime expression returns incorrect result.
2010-10-07 11:07:56 +04:00