Bug #48370 Absolutely wrong calculations with GROUP BY and
decimal fields when using IF
Added the test cases in the above two bugs for regression
testing.
Added additional tests that demonstrate a incomplete fix.
Added a new factory method for Field_new_decimal to
create a field from an (decimal returning) Item.
In the new method made sure that all the precision and
length variables are capped in a proper way.
This is required because Item's can have larger precision
than the decimal fields and thus need to be capped when
creating a field based on an Item type.
Fixed the wrong typecast to Item_decimal.
Bug #48370 Absolutely wrong calculations with GROUP BY and
decimal fields when using IF
Added the test cases in the above two bugs for regression
testing.
Added additional tests that demonstrate a incomplete fix.
Added a new factory method for Field_new_decimal to
create a field from an (decimal returning) Item.
In the new method made sure that all the precision and
length variables are capped in a proper way.
This is required because Item's can have larger precision
than the decimal fields and thus need to be capped when
creating a field based on an Item type.
Fixed the wrong typecast to Item_decimal.
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.
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.
- 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.
Item_sum::set_aggregator() may be called multiple times during query preparation.
On subsequent calls: verify that the aggregator type is the same,
and re-use the existing Aggregator.
sql/item_sum.cc:
In Item_sum::set_aggregator(): re-use existing Aggregator if already set.
Remove some friend declarations, add some accessor functions.
Cleanup some DBUG_ENTER and DBUG_RETURN code.
sql/item_sum.h:
Make some member fields private, add accessors instead.
Remove some un-necessary friend declarations.
Remove some default arguments from constructors.
sql/opt_sum.cc:
Use accessor functions in Item_sum.
sql/sql_select.cc:
Fix mis-spelled DBUG_ENTER text.
Use accessor functions in Item_sum.
sql/sql_yacc.yy:
Use explicit true/false rather than default arguments when constructing
Item_sum_xxx objects.
Item_sum::set_aggregator() may be called multiple times during query preparation.
On subsequent calls: verify that the aggregator type is the same,
and re-use the existing Aggregator.
Use min(max_heap_table_size, tmp_table_size) instead
per-file comments:
sql/item_sum.cc
Bug#46018 group_concat(distinct ...) uses max_heap_table_size for memory allocations
Item_sum_**::setup fixed, so they use ram_limitation() for Unique-s they embed
sql/item_sum.h
Bug#46018 group_concat(distinct ...) uses max_heap_table_size for memory allocations
Item_sum::ram_limitation() declared
Use min(max_heap_table_size, tmp_table_size) instead
per-file comments:
sql/item_sum.cc
Bug#46018 group_concat(distinct ...) uses max_heap_table_size for memory allocations
Item_sum_**::setup fixed, so they use ram_limitation() for Unique-s they embed
sql/item_sum.h
Bug#46018 group_concat(distinct ...) uses max_heap_table_size for memory allocations
Item_sum::ram_limitation() declared
* 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.
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.
sort_buffer_size cannot allocate
The NULL return from tree_insert() (on low memory) was not
checked for in Item_func_group_concat::add(). As a result
on low memory conditions a crash happens.
Fixed by properly checking the return code.
sort_buffer_size cannot allocate
The NULL return from tree_insert() (on low memory) was not
checked for in Item_func_group_concat::add(). As a result
on low memory conditions a crash happens.
Fixed by properly checking the return code.
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.
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.
- Make elimination check to be able detect cases like t.primary_key_col1=othertbl.col AND t.primary_key_col2=func(t.primary_key_col1).
These are needed to handle e.g. the case of func() being a correlated subquery that selects the latest value.
- If we've removed a condition with subquery predicate, EXPLAIN [EXTENDED] won't show the subquery anymore
sql/item.cc:
MWL#17: Table elimination
- Add tem_field::check_column_usage_processor(). it allows to check which key parts a condition depends on.
sql/item.h:
MWL#17: Table elimination
- Add tem_field::check_column_usage_processor(). it allows to check which key parts a condition depends on.
sql/item_subselect.cc:
MWL#17: Table elimination
- Item_subselect got 'eliminated' attribute. It is used only to determine if the subselect should be printed by EXPLAIN.
- Item_subselect got List<Item> refers_to - a list of item in the current select that are referred to from within the subselect.
- Added Item_*::check_column_usage_processor(). it allows to check which key parts a condition depends on.
- Added a comment about possible problem in Item_subselect::walk
sql/item_subselect.h:
MWL#17: Table elimination
- Item_subselect got 'eliminated' attribute. It is used only to determine if the subselect should be printed by EXPLAIN.
- Item_subselect got List<Item> refers_to - a list of item in the current select that are referred to from within the subselect.
- Added Item_*::check_column_usage_processor(). it allows to check which key parts a condition depends on.
sql/item_sum.cc:
MWL#17: Table elimination
sql/sql_lex.cc:
MWL#17: Table elimination
sql/sql_lex.h:
MWL#17: Table elimination
sql/sql_select.h:
MWL#17: Table elimination
- Make elimination work with aggregate functions. The problem was that aggregate functions
reported all table bits in used_tables(), and that prevented table elimination. Fixed by
making aggregate functions return more correct value from used_tables().
mysql-test/r/ps_11bugs.result:
MWL#17: Table elimination
- Update test results. The difference is because of Item_ref change: outer references to constants
are now recognized as constants, too.
mysql-test/r/subselect.result:
- Update test results. The difference is because of Item_ref change: outer references to constants
are now recognized as constants, too.
mysql-test/r/table_elim.result:
MWL#17: Table elimination
- Check that elimination works in presense of aggreagate functions
mysql-test/t/table_elim.test:
MWL#17: Table elimination
- Check that elimination works in presense of aggreagate functions
sql/item.h:
MWL#17: Table elimination
- Add Item_ref::const_item() which calls (*ref)->const_item(). Before this diff Item_ref used the
default implementation of const_item(){ return used_tables()==0; }. This is no longer true, as
COUNT(*) now has used_tables()==0 but const_item()==FALSE.
sql/item_sum.cc:
MWL#17: Table elimination
- Make Item_sum() and it descendants not to return all bits in used_tables(). This is needed
because otherwise table elimination can't work in presense of aggregate functions
- COUNT(*) now has used_tables()==0 and const_item()==FALSE. Had to change
Item_ref::const_item() to account for this.
sql/item_sum.h:
MWL#17: Table elimination
- Add comments
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
The copy of the original arguments of a aggregate function was not
initialized until after fix_fields().
Sometimes (e.g. when there's an error processing the statement)
the print() can be called with no corresponding fix_fields() call.
Fixed by adding a check if the Item is fixed before using the arguments
copy.
mysql-test/r/explain.result:
Bug #43354: test case
mysql-test/t/explain.test:
Bug #43354: test case
sql/item_sum.cc:
Bug #43354: use the argument list copy only if it's initialized
The copy of the original arguments of a aggregate function was not
initialized until after fix_fields().
Sometimes (e.g. when there's an error processing the statement)
the print() can be called with no corresponding fix_fields() call.
Fixed by adding a check if the Item is fixed before using the arguments
copy.
- Added braces around expressions with &&, ||, & and |
- Added empty line before ; for empty while and for loops
- Added () around if with assignments
- Removed const before function returning simple type
Changed BUILD scripts to not build with NDB
BUILD/SETUP.sh:
By default, don't build ndb with --max in Maria tree.
NDB is not kept up to date anyway in 5.1
client/mysql.cc:
Added braces around && to get rid of compiler warnings
sql/event_db_repository.cc:
Added braces around && to get rid of compiler warnings
sql/events.cc:
Added braces around && to get rid of compiler warnings
sql/field.cc:
Added braces around && to get rid of compiler warnings
Fixed for loops
sql/field.h:
Added braces around & to get rid of compiler warnings
sql/field_conv.cc:
Added braces around && to get rid of compiler warnings
Fixed bug when copying between DATETIME fields and strict dates are used
Removed not needeed else
sql/gstream.cc:
Added braces around && to get rid of compiler warnings
sql/ha_ndbcluster.cc:
Added braces around && to get rid of compiler warnings
Added {} to get rid of compiler warnings
sql/handler.cc:
Added braces around && to get rid of compiler warnings
sql/item.cc:
Added braces around && to get rid of compiler warnings
sql/item_cmpfunc.cc:
Added braces around && to get rid of compiler warnings
Removed some not needed space
sql/item_func.cc:
Added braces around && to get rid of compiler warnings
sql/item_strfunc.cc:
Added braces around && to get rid of compiler warnings
sql/item_subselect.cc:
Added braces around && to get rid of compiler warnings
sql/item_sum.cc:
Added braces around && to get rid of compiler warnings
sql/item_timefunc.cc:
Added braces around && to get rid of compiler warnings
sql/item_xmlfunc.cc:
Added empty line before ; for empty while and for loops
sql/log.cc:
Added braces around && to get rid of compiler warnings
sql/log_event.cc:
Added braces around && to get rid of compiler warnings
Removed not needed else
sql/log_event_old.cc:
Added braces around && to get rid of compiler warnings
sql/opt_range.cc:
Added braces around && to get rid of compiler warnings
sql/opt_sum.cc:
Added braces around && to get rid of compiler warnings
sql/set_var.cc:
Added empty line before ; for empty while and for loops
Added () around if with assignments
sql/slave.cc:
Added braces around && to get rid of compiler warnings
Added empty line before ; for empty while and for loops
sql/spatial.h:
Added braces around && to get rid of compiler warnings
sql/sql_acl.cc:
Added braces around && to get rid of compiler warnings
sql/sql_analyse.cc:
Added empty line before ; for empty while and for loops
sql/sql_base.cc:
Added braces around && to get rid of compiler warnings
sql/sql_connect.cc:
Added braces around && to get rid of compiler warnings
sql/sql_db.cc:
Added braces around && to get rid of compiler warnings
sql/sql_delete.cc:
Added braces around && to get rid of compiler warnings
sql/sql_help.cc:
Added empty line before ; for empty while and for loops
sql/sql_insert.cc:
Added braces around && to get rid of compiler warnings
Added () around if with assignments
sql/sql_lex.cc:
Cast char array references to uchar; Fixed wrong array referencing when using characters > ASCII 128 in SQL statments
Added empty line before ; for empty while and for loops
Trivial indent fixes
Added braces around && to get rid of compiler warnings
sql/sql_load.cc:
Added braces around && to get rid of compiler warnings
sql/sql_parse.cc:
Added braces around && to get rid of compiler warnings
sql/sql_partition.cc:
Added braces around && to get rid of compiler warnings
sql/sql_plugin.cc:
Fixed bug in detecing if option variable should be readonly
Added empty line before ; for empty while and for loops
sql/sql_prepare.cc:
Added braces around && to get rid of compiler warnings
sql/sql_select.cc:
Added braces around && to get rid of compiler warnings
Added () around if with assignments
Added empty line before ; for empty while and for loops
sql/sql_show.cc:
Added braces around && to get rid of compiler warnings
sql/sql_table.cc:
Added braces around && to get rid of compiler warnings
sql/sql_trigger.cc:
Added braces around && to get rid of compiler warnings
sql/sql_update.cc:
Added braces around && to get rid of compiler warnings
sql/sql_yacc.yy:
Added braces around && to get rid of compiler warnings
sql/table.cc:
Added braces around && to get rid of compiler warnings
sql/table.h:
Added braces around && to get rid of compiler warnings
sql/time.cc:
Added braces around && to get rid of compiler warnings
sql/tztime.cc:
Added braces around && to get rid of compiler warnings
sql/uniques.cc:
Added braces around && to get rid of compiler warnings
storage/federated/ha_federated.cc:
Fixed bug in testing of variable to ha_info() (Not critical)
storage/heap/ha_heap.cc:
Added braces around && to get rid of compiler warnings
storage/maria/ha_maria.cc:
Fixed bug: Mark that maria_log_dir_path is readonly
Added braces around && to get rid of compiler warnings
storage/ndb/include/ndbapi/NdbEventOperation.hpp:
Removed const before function returning simple type
storage/ndb/include/ndbapi/NdbOperation.hpp:
Removed const before function returning simple type
storage/ndb/src/ndbapi/Ndb.cpp:
Added empty line before ; for empty while and for loops
storage/ndb/src/ndbapi/NdbEventOperation.cpp:
Removed const before function returning simple type
storage/ndb/src/ndbapi/NdbEventOperationImpl.cpp:
Removed const before function returning simple type
storage/ndb/src/ndbapi/NdbEventOperationImpl.hpp:
Removed const before function returning simple type
storage/ndb/src/ndbapi/NdbRecAttr.cpp:
Added empty line before ; for empty while and for loops
storage/ndb/src/ndbapi/TransporterFacade.hpp:
Added braces around && to get rid of compiler warnings
Related to operator precedence and associativity.
Make the expressions as explicit as possible.
sql/field.h:
Silence gcc-4.3 warning: be more explicit.
sql/item.cc:
Silence gcc-4.3 warning: be more explicit.
sql/item_sum.cc:
Silence gcc-4.3 warning: be more explicit.
sql/log_event.cc:
Silence gcc-4.3 warning: be more explicit.
sql/spatial.h:
Silence gcc-4.3 warning: be more explicit.
sql/sql_lex.cc:
Silence gcc-4.3 warning: be more explicit.
sql/table.h:
Silence gcc-4.3 warning: be more explicit.
storage/federated/ha_federated.cc:
Fix operator precedence bug.
storage/heap/ha_heap.cc:
Silence gcc-4.3 warning: be more explicit.
