Analysis:
A query with implicit grouping is one with aggregate functions and
no GROUP BY clause. MariaDB inherits from MySQL an SQL extenstion
that allows mixing aggregate functions with non-aggregate fields.
If a query with such mixed select clause produces an empty result
set, the meaning of aggregate functions is well defined - either
NULL (MIN, MAX, etc.), or 0 (count(*)). However the non-aggregated
fields must also have some value, and the only reasonable value in
the case of empty result is NULL.
The cause of the many wrong results was that if a field is declared
as non-nullable (e.g. because it is a PK or NOT NULL), the semantic
analysis and the optimization phases treat this field as non-nullable,
and generate all related query plan elements based on this assumption.
Later during execution, these incorrectly configured/generated query
plan elements result in a wrong result because the selected fields
are not null due to the not-null assumption during optimization.
Solution:
Detect before the context analysys phase that a query uses implicit
grouping with mixed aggregates/non-aggregates, and set all fields
as nullable. The parser already walks the SELECT clause, and
already sets Item::with_sum_func for Items that reference aggreagate
functions. The patch adds a symmetric Item::with_field so that all
Items that reference an Item_field are marked during their
construction at parse time in the same way as with aggregate function
use.
- Fixed some issues with partitions and connection_string, which also fixed lp:716890 "Pre- and post-recovery crash in Aria"
- Fixed wrong assert in Aria
Now need to merge with latest xtradb before pushing
sql/ha_partition.cc:
Ensure that m_ordered_rec_buffer is not freed before close.
sql/mysqld.cc:
Changed to use opt_stack_trace instead of opt_pstack.
Removed references to pstack
sql/partition_element.h:
Ensure that connect_string is initialized
storage/maria/ma_key_recover.c:
Fixed wrong assert
- Removed files specific to compiling on OS/2
- Removed files specific to SCO Unix packaging
- Removed "libmysqld/copyright", text is included in documentation
- Removed LaTeX headers for NDB Doxygen documentation
- Removed obsolete NDB files
- Removed "mkisofs" binaries
- Removed the "cvs2cl.pl" script
- Changed a few GPL texts to use "program" instead of "library"
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.
multiline inserts into partition
Bug#57071: EXTRACT(WEEK from date_col) cannot be
allowed as partitioning function
Renamed function according to reviewers comments.
sql/item.h:
better name of processor function
sql/item_func.h:
better name of processor function
sql/item_timefunc.h:
better name of processor function
sql/sql_partition.cc:
better name of processor function
Updated comment.
Bug#57071: EXTRACT(WEEK from date_col) cannot be allowed as partitioning function
There were functions allowed as partitioning functions
that implicit allowed cast. That could result in unacceptable
behaviour.
Solution was to check that the arguments of date and time functions
have allowed types (field and date/datetime/time depending on function).
mysql-test/r/partition.result:
Updated result
mysql-test/r/partition_error.result:
Updated result
mysql-test/suite/parts/inc/part_supported_sql_funcs_main.inc:
disabled test with not allowed arguments.
mysql-test/suite/parts/r/part_supported_sql_func_innodb.result:
Updated result
mysql-test/suite/parts/r/part_supported_sql_func_myisam.result:
Updated result
mysql-test/t/partition.test:
Fixed typo in bug number and removed non allowed function (bad argument)
mysql-test/t/partition_error.test:
Added tests to verify correct type of argument.
sql/item.h:
Renamed processor since it is no longer only for timezone
sql/item_func.h:
Added help functions for checking date/time/datetime arguments.
sql/item_timefunc.h:
Added processors for argument correctness
sql/sql_partition.cc:
renamed the processor for checking arguments.
- Fixed problem with oqgraph and 'make dist'
Note that after this merge we have a problem show in join_outer where we examine too many rows in one specific case (related to BUG#57024).
This will be fixed when mwl#128 is merged into 5.3.
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.
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
Fix some bugs where we stored values other than 0 or 1 in my_bool
Fixed some compiler warnings
client/mysql.cc:
Changed interrupted_query from my_bool to int, as we stored 2 in it.
client/mysqladmin.cc:
Changed return variable type to same type as function value type
client/mysqltest.cc:
Changed 'found' to int as we store other values than 0 or 1 into it
Changed type for parameter of set_reconnect() to match usage.
extra/libevent/evbuffer.c:
Added __attribute__((unused))
extra/libevent/event.c:
Added __attribute__((unused))
extra/libevent/signal.c:
Added __attribute__((unused))
sql/event_data_objects.h:
my_bool -> bool
sql/event_db_repository.cc:
my_bool -> bool
sql/event_db_repository.h:
my_bool -> bool
sql/event_parse_data.h:
my_bool -> bool
sql/events.cc:
my_bool -> bool
sql/events.h:
my_bool -> bool
sql/field.cc:
my_bool -> bool
sql/field.h:
my_bool -> bool
sql/hash_filo.h:
my_bool -> bool
sql/item.cc:
my_bool -> bool
sql/item.h:
my_bool -> bool
sql/item_cmpfunc.h:
my_bool -> bool
Changed result_for_null_param from my_bool to int as we stored -1 in it.
sql/item_func.cc:
my_bool -> bool
Modified udf wrapper functions so that the UDF functions would continue to use my_bool. (To keep compatibility with UDF:s)
sql/item_func.h:
my_bool -> bool
sql/item_subselect.h:
my_bool -> bool
sql/item_sum.cc:
Modified udf wrapper functions so that the UDF functions would continue to use my_bool. (To keep compatibility with UDF:s)
sql/parse_file.h:
my_bool -> bool
sql/rpl_mi.h:
my_bool -> bool
sql/sp_rcontext.h:
my_bool -> bool
sql/sql_analyse.h:
my_bool -> bool
sql/sql_base.cc:
Change some assignments so that we don't initialize bool variables with int's.
sql/sql_bitmap.h:
my_bool -> bool
sql/sql_cache.cc:
my_bool -> bool
sql/sql_cache.h:
my_bool -> bool
sql/sql_class.h:
my_bool -> bool
sql/sql_insert.cc:
Change some assignments so that we don't initialize bool variables with int's.
sql/sql_prepare.cc:
my_bool -> bool
sql/table.h:
my_bool -> bool
storage/maria/ma_check.c:
Removed duplicate assignment
strings/decimal.c:
Fixed wrong variable usage.
Don't do complex arithmetic on bool when simple works.
mysql-test/r/group_by.result:
Added test that showed problems that no_rows_in_results() didn't work for expressions
mysql-test/r/subselect4.result:
Test case for LP#612894
mysql-test/t/group_by.test:
Added test that showed problems that no_rows_in_results() didn't work for expressions
mysql-test/t/subselect4.test:
Test case for LP#612894
sql/item.h:
Added restore_to_before_no_rows_in_result()
Added function processor for no_rows_in_results() and restore_to_before_no_rows_in_results() to ensure it works with functions
Fix that above functions are handled by Item_ref()
sql/item_func.h:
Ensure that no_rows_in_results() and restore_to_before_no_rows_in_result() are called for all function arguments
sql/item_sum.cc:
Added restore_to_before_no_rows_in_result() to restore settings after Item_sum_hybrid::no_rows_in_result() was called.
This is needed to handle the case where we have made 'make_const()' on the item in opt_sum(), but the item will be reused again in a sub query.
Ignore multiple calls to no_rows_in_result() as Item_ref is calling it twice.
sql/item_sum.h:
Added restore_to_before_no_rows_in_result();
sql/sql_select.cc:
Added reset of no_rows_in_result() for JOIN::reinit()
sql/sql_select.h:
Added marker if no_rows_in_result() is called.
An user assignment variable expression that's
evaluated in a logical expression context
(Item::val_bool()) can be pre-calculated in a
temporary table for GROUP BY.
However when the expression value is used after the
temp table creation it was re-evaluated instead of
being read from the temp table due to a missing
val_bool_result() method.
Fixed by implementing the method.
- Marked a couple of tests with --big
- Fixed xtradb/handler/ha_innodb.cc to call explain_filename()
storage/xtradb/handler/ha_innodb.cc:
Call explain_filename() to get proper names for partitioned tables
Several problems fixed :
1. Non constant expressions in UNION ... ORDER BY were not correctly cleaned up
in st_select_lex_unit::cleanup() causing crashes in EXPLAIN EXTENDED because of
fields quoted by these expressions pointing to the already freed temporary table
used to calculate the UNION.
Fixed by correctly cleaning up expressions of any depth.
2. Subqueries in the order by part of UNION ... ORDER BY ... caused a crash in
EXPLAIN EXTENDED because of a transformation attempt made during EXPLAIN EXTENDED
execution. Fixed by not doing the transformation when in EXPLAIN.
3. Fulltext functions caused crash when in the ORDER BY part of an un-parenthesized
UNION that gets "promoted" to be valid for the whole union, e.g.
SELECT * FROM t1 UNION SELECT * FROM t2 ORDER BY MATCHES (a) AGAINST ('abc' IN BOOLEAN MODE).
This is a case that demonstrates a more general problem of parts of the query being
moved to another level. When doing such transformation late in the optimization run
when most of the flags about the contents of the query are already aggregated it's possible
to "split" the flags so that they correctly reflect the new queries after the transformation.
In specific the ST_SELECT_LEX::ftfunc_list is holding all the free text function for all the
parts of the second SELECT in the UNION and we don't know what part of that is in the ORDER BY
that we're to move to the UNION level and what part is about the other parts of the second SELECT.
Fixed by throwing and error when such statements are about to be processed by adding a check
for the presence of MATCH() inside the ORDER BY clause that's going to get promoted to UNION.
To workaround this new limitation one must parenthesize the UNION SELECTs and provide a real
global ORDER BY for the UNION outside of the parenthesis.
timestamp primary key
Since TIMESTAMP values are adjusted by the current time zone
settings in both numeric and string contexts, using any
expressions involving TIMESTAMP values as a
(sub)partitioning function leads to undeterministic behavior of
partitioned tables. The effect may vary depending on a storage
engine, it can be either incorrect data being retrieved or
stored, or an assertion failure. The root cause of this is the
fact that the calculated partition ID may differ from a
previously calculated ID for the same data due to timezone
adjustments of the partitioning expression value.
Fixed by disabling any expressions involving TIMESTAMP values
to be used in partitioning functions with the follwing two
exceptions:
1. Creating or altering into a partitioned table that violates
the above rule is not allowed, but opening existing such tables
results in a warning rather than an error so that such tables
could be fixed.
2. UNIX_TIMESTAMP() is the only way to get a
timezone-independent value from a TIMESTAMP column, because it
returns the internal representation (a time_t value) of a
TIMESTAMP argument verbatim. So UNIX_TIMESTAMP(timestamp_column)
is allowed and should be used to fix existing tables if one
wants to use TIMESTAMP columns with partitioning.
mysql-test/r/partition_bug18198.result:
Corrected the error.
mysql-test/r/partition_error.result:
Corrected error texts.
Added test cases for bug #42849.
mysql-test/t/partition_bug18198.test:
Corrected error code.
mysql-test/t/partition_error.test:
Corrected error codes.
Added test cases for bug #42849.
sql/item.h:
Added is_timezone_dependent_processor() to Item.
sql/item_func.h:
Added has_timestamp_args() and the implementation of
is_timezone_dependent_processor() for Item_func.
sql/item_timefunc.h:
Added is_timezone_dependent_processor() to
Item_func_unix_timestamp.
sql/share/errmsg.txt:
Renamed ER_CONST_EXPR_IN_PARTITION_FUNC_ERROR to
ER_WRONG_EXPR_IN_PARTITION_FUNC_ERROR to better reflect the
meaning. Adjusted the error message.
sql/sql_partition.cc:
Modified fix_fields_part_func() to walk through partitioning
expression tree with is_timezone_dependent_processor() and issue
a warning/error if it depends on the timezone settings.
Changed fix_fields_part_func() to a static function since it is
not used anywhere except sql_partition.cc
sql/sql_partition.h:
Removed the unneeded declaration of fix_fields_part_func()
since it is now a static function.
sql/sql_yacc.yy:
ER_CONST_EXPR_IN_PARTITION_FUNC_ERROR ->
ER_WRONG_EXPR_IN_PARTITION_FUNC_ERROR.
MySQL manual describes values of the YEAR(2) field type as follows:
values 00 - 69 mean 2000 - 2069 years and values 70 - 99 mean 1970 - 1999
years. MIN/MAX and comparison functions was comparing them as int values
thus producing wrong result.
Now the Arg_comparator class is extended with compare_year function which
performs correct comparison of the YEAR type.
The Item_sum_hybrid class now uses Item_cache and Arg_comparator objects to
correctly calculate its value.
To allow Arg_comparator to use func_name() function for Item_func and Item_sum
objects the func_name declaration is moved to the Item_result_field class.
A helper function is_owner_equal_func is added to the Arg_comparator class.
It checks whether the Arg_comparator object owner is the <=> function or not.
A helper function setup is added to the Item_sum_hybrid class. It sets up
cache item and comparator.
mysql-test/r/func_group.result:
Added a test case for the bug#43668.
mysql-test/t/func_group.test:
Added a test case for the bug#43668.
sql/item.cc:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
Now Item_cache_int returns the type of cached item.
sql/item.h:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
To allow Arg_comparator to use func_name() function for Item_func and Item_sum
objects the func_name declaration is moved to the Item_result_field class.
sql/item_cmpfunc.cc:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
The Arg_comparator class is extended with compare_year function which
performs correct comparison of the YEAR type.
sql/item_cmpfunc.h:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
The year_as_datetime variable is added to the Arg_comparator class.
It's set to TRUE when YEAR value should be converted to the
YYYY-00-00 00:00:00 format for correct YEAR-DATETIME comparison.
sql/item_geofunc.cc:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
Item_func_spatial_rel::val_int chenged to use Arg_comparator's string
buffers.
sql/item_subselect.h:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
Added an implementation of the virtual func_name function.
sql/item_sum.cc:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
The Item_sum_hybrid class now uses Item_cache and Arg_comparator objects to
correctly calculate its value.
A helper function setup is added to the Item_sum_hybrid class. It sets up
cache item and comparator.
sql/item_sum.h:
Bug#43668: Wrong comparison and MIN/MAX for YEAR(2)
The Item_sum_hybrid class now uses Item_cache and Arg_comparator objects to
correctly calculate its value.
Added an implementation of the virtual func_name function.
- Moved some code from innodb_plugin to xtradb, to ensure that all tests runs
- Did changes in pbxt and maria storage engines becasue of changes in thd->query
- Reverted wrong code in sql_table.cc for how ROW_FORMAT is used.
This is a re-commit of Monty's merge to eliminate an extra commit from
MySQL-5.1.42 that was accidentally included in the merge.
This is a merge of the MySQL 5.1.41 clone-off (clone-5.1.41-build). In
case there are any extra changes done before final MySQL 5.1.41
release, these will need to be merged later before MariaDB 5.1.41
release.
* Finished Monty and Jani's merge
* Some InnoDB tests still fail (because it's old xtradb code run against
newer testsuite). They are expected to go after mergning with the latest
xtradb.
The problem was that creating a DECIMAL column from a decimal
value could lead to a failed assertion as decimal values can
have a higher precision than those attached to a table. The
assert could be triggered by creating a table from a decimal
with a large (> 30) scale. Also, there was a problem in
calculating the number of digits in the integral and fractional
parts if both exceeded the maximum number of digits permitted
by the new decimal type.
The solution is to ensure that truncation procedure is executed
when deducing a DECIMAL column from a decimal value of higher
precision. If the integer part is equal to or bigger than the
maximum precision for the DECIMAL type (65), the integer part
is truncated to fit and the fractional becomes zero. Otherwise,
the fractional part is truncated to fit into the space left
after the integer part is copied.
This patch borrows code and ideas from Martin Hansson's patch.
mysql-test/r/type_newdecimal.result:
Add test case result for Bug#45261. Also, update test case to
reflect that an additive operation increases the precision of
the resulting type by 1.
mysql-test/t/type_newdecimal.test:
Add test case for Bug#45261
sql/field.cc:
Added DBUG_ASSERT to ensure object's invariant is maintained.
Implement method to create a field to hold a decimal value
from an item.
sql/field.h:
Explain member variable. Add method to create a new decimal field.
sql/item.cc:
The precision should only be capped when storing the value
on a table. Also, this makes it impossible to calculate the
integer part if Item::decimals (the scale) is larger than the
precision.
sql/item.h:
Simplify calculation of integer part.
sql/item_cmpfunc.cc:
Do not limit the precision. It will be capped later.
sql/item_func.cc:
Use new method for allocating a new decimal field.
Add a specialized method for retrieving the precision
of a user variable item.
sql/item_func.h:
Add method to return the precision of a user variable.
sql/item_sum.cc:
Use new method for allocating a new decimal field.
sql/my_decimal.h:
The integer part could be improperly calculated for a decimal
with 31 digits in the fractional part.
sql/sql_select.cc:
Use new method which truncates the integer or decimal parts
as needed.
match against.
Server crashes when executing prepared statement with duplicating
MATCH() function calls in SELECT and ORDER BY expressions, e.g.:
SELECT MATCH(a) AGAINST('test') FROM t1 ORDER BY MATCH(a) AGAINST('test')
This query gets optimized by the server, so the value returned
by MATCH() from the SELECT list is reused for ORDER BY purposes.
To make this optimization server is comparing items from
SELECT and ORDER BY lists. We were getting server crash because
comparision function for MATCH() item is not intended to be called
at this point of execution.
In 5.0 and 5.1 this problem is workarounded by resetting MATCH()
item to the state as it was during PREPARE.
In 6.0 correct comparision function will be implemented and
duplicating MATCH() items from the ORDER BY list will be
optimized.
mysql-test/r/fulltext.result:
Updated with the test case for Bug#37740
mysql-test/t/fulltext.test:
A test case for Bug#37740.
sql/item_func.h:
True initialization of 'table' happens in ::fix_fields(). As
Item_func_match::eq() may be called before ::fix_fields(), it is
expected that 'table' is initialized to 0 when it is reused.
This is mostly affecting prepared statements, when the same item
doesn't get destroyed, but rather cleaned up and reused.
Using DECIMAL constants with more than 65 digits in CREATE
TABLE ... SELECT led to bogus errors in release builds or
assertion failures in debug builds.
The problem was in inconsistency in how DECIMAL constants and
fields are handled internally. We allow arbitrarily long
DECIMAL constants, whereas DECIMAL(M,D) columns are limited to
M<=65 and D<=30. my_decimal_precision_to_length() was used in
both Item and Field code and truncated precision to
DECIMAL_MAX_PRECISION when calculating value length without
adjusting precision and decimals. As a result, a DECIMAL
constant with more than 65 digits ended up having length less
than precision or decimals which led to assertion failures.
Fixed by modifying my_decimal_precision_to_length() so that
precision is truncated to DECIMAL_MAX_PRECISION only for Field
object which is indicated by the new 'truncate' parameter.
Another inconsistency fixed by this patch is how DECIMAL
constants and expressions are handled for CREATE ... SELECT.
create_tmp_field_from_item() (which is used for constants) was
changed as a part of the bugfix for bug #24907 to handle long
DECIMAL constants gracefully. Item_func::tmp_table_field()
(which is used for expressions) on the other hand was still
using a simplistic approach when creating a Field_new_decimal
from a DECIMAL expression.
mysql-test/r/type_newdecimal.result:
Added a test case for bug #45262.
mysql-test/t/type_newdecimal.test:
Added a test case for bug #45262.
sql/item.cc:
Use the new 'truncate' parameter in
my_decimal_precision_to_length().
sql/item_cmpfunc.cc:
Use the new 'truncate' parameter in
my_decimal_precision_to_length().
sql/item_func.cc:
1. Use the new 'truncate' parameter in
my_decimal_precision_to_length().
2. Do not truncate decimal precision to DECIMAL_MAX_PRECISION
for additive expressions involving long DECIMAL constants.
3. Fixed an incosistency in how DECIMAL constants and
expressions are handled for CREATE ... SELECT.
sql/item_func.h:
Use the new 'truncate' parameter in
my_decimal_precision_to_length().
sql/item_sum.cc:
Use the new 'truncate' parameter in
my_decimal_precision_to_length().
sql/my_decimal.h:
Do not truncate precision to DECIMAL_MAX_PRECISION
when calculating length in
my_decimal_precision_to_length() if 'truncate' parameter
is FALSE.
sql/sql_select.cc:
1. Use the new 'truncate' parameter in
my_decimal_precision_to_length().
2. Use a more correct logic when adjusting value's length.
assertion .\filesort.cc, line 797
A query with the "ORDER BY @@some_system_variable" clause,
where @@some_system_variable is NULL, causes assertion
failure in the filesort procedures.
The reason of the failure is in the value of
Item_func_get_system_var::maybe_null: it was unconditionally
set to false even if the value of a variable was NULL.
mysql-test/r/variables.result:
Added test case for bug #42778.
mysql-test/suite/sys_vars/r/innodb_data_home_dir_basic.result:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/r/innodb_flush_method_basic.result:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/r/rpl_init_slave_func.result:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/r/ssl_capath_basic.result:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/r/ssl_cipher_basic.result:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/t/innodb_data_home_dir_basic.test:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/t/innodb_flush_method_basic.test:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/t/ssl_capath_basic.test:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/suite/sys_vars/t/ssl_cipher_basic.test:
Updated test case for bug #42778:
system variables were NOT NULL, now they are nullable.
mysql-test/t/variables.test:
Added test case for bug #42778.
sql/item.cc:
Bug #42778: delete order by null global variable causes
assertion .\filesort.cc, line 797
The longlong_from_string_with_check function has been modified
to skip unwanted warnings: now it uses the THD::no_errors
flag to suppress warnings.
The Item_func_get_system_var::update_null_value method
sets the no_error flag.
sql/item_func.cc:
Bug #42778: delete order by null global variable causes
assertion .\filesort.cc, line 797
1. The Item_func_get_system_var::fix_length_and_dec method
has been modified to make system variables truly nullable.
2. The Item_func_get_system_var::update_null_value method
method has been overloaded with a simple wrapper (like
Item_field::update_null_value) to suppress unwanted warnings
from Item_func_get_system_var::val_int() calls on non-numeric
variable values: the Item_func_get_system_var::update_null_value
method sets and restores THD::no_errors flag for a nested
call of the longlong_from_string_with_check function.
sql/item_func.h:
Bug #42778: delete order by null global variable causes
assertion .\filesort.cc, line 797
The Item_func_get_system_var::update_null_value method
method has been overloaded.
The RAND(N) function where the N is a field of "constant" table
(table of single row) failed with a SIGFPE.
Evaluation of RAND(N) rely on constant status of its argument.
Current server "seeded" random value for each constant argument
only once, in the Item_func_rand::fix_fields method.
Then the server skipped a call to seed_random() in the
Item_func_rand::val_real method for such constant arguments.
However, non-constant state of an argument may be changed
after the call to fix_fields, if an argument is a field of
"constant" table. Thus, pre-initialization of random value
in the fix_fields method is too early.
Initialization of random value by seed_random() has been
removed from Item_func_rand::fix_fields method.
The Item_func_rand::val_real method has been modified to
call seed_random() on the first evaluation of this method
if an argument is a function.
mysql-test/r/func_math.result:
Added test case for bug #44768.
mysql-test/t/func_math.test:
Added test case for bug #44768.
sql/item_func.cc:
Bug #44768: SIGFPE crash when selecting rand from a view containing null
1. Initialization of random value by seed_random() has been
removed from Item_func_rand::fix_fields method.
2. The Item_func_rand::val_real method has been modified to
call seed_random() on the first evaluation of this method
if an argument is a function.
sql/item_func.h:
Bug #44768: SIGFPE crash when selecting rand from a view containing null
1. The Item_func_rand::first_eval has been added to trace
the first evaluation of the val_real method.
2. The Item_func_rand::cleanup method has been added to
cleanup the first_eval flag.
