read buffer
Setting read buffer to values greater than SSIZE_MAX results in
unexpected behavior.
According to read(2) manual:
If count is greater than SSIZE_MAX, the result is unspecified.
Set upper limit for read_buffer_size and read_rnd_buffer_size to
SSIZE_MAX.
The order of acquiring LOCK_mysql_create_db
and wait_if_global_read_lock() was wrong. It could happen
that a thread held LOCK_mysql_create_db while waiting for
the global read lock to be released. The thread with the
global read lock could try to administrate a database too.
It would first try to lock LOCK_mysql_create_db and hang...
The check if the current thread has the global read lock
is done in wait_if_global_read_lock(), which could not be
reached because of the hang in LOCK_mysql_create_db.
Now I exchanged the order of acquiring LOCK_mysql_create_db
and wait_if_global_read_lock(). This makes
wait_if_global_read_lock() fail with an error message for
the thread with the global read lock. No deadlock happens.
The convert_constant_item() function converts constant items to ints on
prepare phase to optimize execution speed. In this case it tries to evaluate
subselect which contains a derived table and is contained in a derived table.
All derived tables are filled only after all derived tables are prepared.
So evaluation of subselect with derived table at the prepare phase will
return a wrong result.
A new flag with_subselect is added to the Item class. It indicates that
expression which this item represents is a subselect or contains a subselect.
It is set to 0 by default. It is set to 1 in the Item_subselect constructor
for subselects.
For Item_func and Item_cond derived classes it is set after fixing any argument
in Item_func::fix_fields() and Item_cond::fix_fields accordingly.
The convert_constant_item() function now doesn't convert a constant item
if the with_subselect flag set in it.
specific to 5.0 version of the patch is motivated by the fact that a wrapper over
MYSQLLOG::write can not help in 5.0 where query's charset is embedded into event instance in the constructor.
- When manually constructing a SEL_TREE for "t.key NOT IN(...)", take into account that
get_mm_parts may return a tree with type SEL_TREE::IMPOSSIBLE
- Added missing OOM checks
- Added comments
Stored procedure execution sometimes placed the address of auto variables
in the list of Item changes to undo in THD::rollback_item_tree_changes().
This could cause stack corruption.
over two views when using syntax with curly braces.
Each outer join operation must be placed in a separate
nest. This was not done when the syntax with curly braces
was used. In some cases, in particular, for queries with outer
join operation over views it could cause a crash.
itself when executing queries referring to a view with GROUP BY
an expression containing non-constant interval.
It happened because Item_date_add_interval::eq neglected the
fact that the method can be applied to an expression of the form
date(col) + interval time_to_sec(col) second
at the time when col could not be evaluated yet.
An attempt to evaluate time_to_sec(col) in this method resulted
in a crash.
A pattern to generate binlog for DROPped temp table in close_temporary_tables
was buggy: could not deal with a grave-accent-in-name table.
The fix exploits `append_identifier()' for quoting and duplicating accents.
from within triggers
Add support for passing NEW.x as INOUT and OUT parameters to stored
procedures. Passing NEW.x as INOUT parameter requires SELECT and
UPDATE privileges on that column, and passing it as OUT parameter
requires only UPDATE privilege.
When a view statement is compiled on CREATE VIEW time, most of the
optimizations should not be done. Finding the right optimization
for a subquery is one of them.
Unfortunately the optimizer is resolving the column references of
the left expression of IN subqueries in the process of deciding
witch optimization to use (if needed). So there should be a
special case in Item_in_subselect::fix_fields() : check the
validity of the left expression of IN subqueries in CREATE VIEW
mode and then proceed as normal.
