The bug caused memory corruption for some queries with top OR level
in the WHERE condition if they contained equality predicates and
other sargable predicates in disjunctive parts of the condition.
The corruption happened because the upper bound of the memory
allocated for KEY_FIELD and SARGABLE_PARAM internal structures
containing info about potential lookup keys was calculated incorrectly
in some cases. In particular it was calculated incorrectly when the
WHERE condition was an OR formula with disjuncts being AND formulas
including equalities and other sargable predicates.
ORDER BY is used
The range analysis module did not correctly signal to the
handler that a range represents a ref (EQ_RANGE flag). This causes
non-range queries like
SELECT ... FROM ... WHERE keypart_1=const, ..., keypart_n=const
ORDER BY ... FOR UPDATE
to wait for a lock unneccesarily if another running transaction uses
SELECT ... FOR UPDATE on the same table.
Fixed by setting EQ_RANGE for all range accesses that represent
an equality predicate.
The cli_read_binary_rows function is used to fetch data from the server
after a prepared statement execution. It accepts a statement handler and gets
the connection handler from it. But when the auto-reconnect option is set
the connection handler is reset to NULL after reconnection because the
prepared statement is lost and the handler became useless. This case
wasn't checked in the cli_read_binary_rows function and caused server crash.
Now the cli_read_binary_rows function checks the connection handler to be
not NULL and returns an error if it is.
MySQL replicates the time zone only when operations that involve
it are performed. This is controlled by a flag. But this flag
is set only on successful operation.
The flag must be set also when there is an error that involves
a timezone (so the master would replicate the error to the slaves).
Fixed by moving the setting of the flag before the operation
(so it apples to errors as well).
VIEW".
mysql_list_fields() C API function would incorrectly set MYSQL_FIELD::decimals
member for some view columns.
The problem was in an incomplete implementation of
Item_ident_for_show::make_field(), which is responsible for view
columns metadata.
This bug manifested itself for queries with grouping by columns of
the BIT type. It led to wrong comparisons of bit-field values and
wrong result sets.
Bit-field values never cannot be compared as binary values. Yet
the class Field_bit had an implementation of the cmp method that
compared bit-fields values as binary values.
Also the get_image and set_image methods of the base class Field
cannot be used for objects of the Field_bit class.
Now these methods are declared as virtual and specific implementations
of the methods are provided for the class Field_bit.
statement being KILLed".
When statement which was trying to obtain write lock on then table and
which was blocked by existing read lock was killed, concurrent statements
that were trying to obtain read locks on the same table and that were
blocked by the presence of this pending write lock were not woken up and
had to wait until this first read lock goes away.
This problem was caused by the fact that we forgot to wake up threads
which pending requests could have been satisfied after removing lock
request for the killed thread.
The patch solves the problem by waking up those threads in such situation.
Test for this bug will be added to 5.1 only as it has much better
facilities for its implementation. Particularly, by using I_S.PROCESSLIST
and wait_condition.inc script we can wait until thread will be blocked on
certain table lock without relying on unconditional sleep (which usage
increases time needed for test runs and might cause spurious test
failures on slower platforms).
A test case was waiting for a fixed number of seconds for a specific
state of the slave IO thread to take place.
Fixed by waiting in a loop for that specific thread state instead
(or timeout).
(Regression, caused by a patch for the bug 22646).
Problem: when result type of date_format() was changed from
binary string to character string, mixing date_format()
with a ascii column in CONCAT() stopped to work.
Fix:
- adding "repertoire" flag into DTCollation class,
to mark items which can return only pure ASCII strings.
- allow character set conversion from pure ASCII to other character sets.
The SELECT query with more than 31 nested dependent SELECT queries returned
wrong result.
New error message has been added: ER_TOO_HIGH_LEVEL_OF_NESTING_FOR_SELECT.
It will be reported as: "Too high level of nesting for select".
