crashes server!
The problem affects the scenario when index merge is followed by a filesort
and the sort buffer is not big enough for all the sort keys.
In this case the filesort function will read the data to the end through the
index merge quick access method (and thus closing the cursor etc),
but will leave the pointer to the quick select method in place.
It will then create a temporary file to hold the results of the filesort and
will add it as a sort output file (in sort.io_cache).
Note that filesort will copy the original 'sort' structure in an automatic
variable and restore it after it's done.
As a result at exiting filesort() we have a sort.io_cache filled in and
nothing else (as a result of close of the cursors at end of reading data
through index merge).
Now create_sort_index() will note that there is a select and will clean it up
(as it's been used already by filesort() reading the data in). While doing that
a special case in the index merge destructor will clean up the sort.io_cache,
assuming it's an output of the index merge method and is not needed anymore.
As a result the code that tries to read the data back from the filesort output
will get no data in both memory and disk and will crash.
Fixed similarly to how filesort() does it : by copying the sort.io_cache structure
to a local variable, removing the pointer to the io_cache (so that it's not freed
by QUICK_INDEX_MERGE_SELECT::~QUICK_INDEX_MERGE_SELECT) and restoring the original
structure (together with the valid pointer) after the cleanup is done.
This is a safe thing to do because all the structures are already cleaned up by
hitting the end of the index merge's read method (QUICK_INDEX_MERGE_SELECT::get_next())
and the cleanup code being written in a way that tolerates repeating cleanups.
The SQL-mode PAD_CHAR_TO_FULL_LENGTH could prevent a DROP USER
statement from privileges associated with the user being dropped.
What ocurred was that reading from the User and Host fields of
the tables tables_priv or columns_priv would yield values padded
with spaces, causing a failure to match a specified user or host
('user' != 'user ');
The solution is to disregard the PAD_CHAR_TO_FULL_LENGTH mode
when iterating over and matching values in the privileges tables
for a DROP USER statement.
statements missed from general log
A refinement of the test in the previous patch to avoid
using sleep as a means to ensure that timestamps are
added to the log entries.
WHERE and GROUP BY clause
Loose index scan may use range conditions on the argument of
the MIN/MAX aggregate functions to find the beginning/end of
the interval that satisfies the range conditions in a single go.
These range conditions may have open or closed minimum/maximum
values. When the comparison returns 0 (equal) the code should
check the type of the min/max values of the current interval
and accept or reject the row based on whether the limit is
open or not.
There was a wrong composite condition on checking this and it was
not working in all cases.
Fixed by simplifying the conditions and reversing the logic.
This test uses SHOW STATUS and the like, which may be unstable in the face
of logging to table, since the CSV handler is actively executing operations
and thus incrementing the counters.
Fixed by disabling logging to table for the duration of the test and restoring
it afterwards. This causes various counters to properly start counting from zero
and never advance due to CSV operations.
uninitialized variable used as subscript
Grouping select from a "constant" InnoDB table (a table
of a single row) joined with other tables caused a crash.
The problem is that when a optimization of read-only transactions
(bypass 2-phase commit) was implemented, it removed the code that
reseted the XID once a transaction wasn't active anymore:
sql/sql_parse.cc:
- bzero(&thd->transaction.stmt, sizeof(thd->transaction.stmt));
- if (!thd->active_transaction())
- thd->transaction.xid_state.xid.null();
+ thd->transaction.stmt.reset();
This mostly worked fine as the transaction commit and rollback
functions (in handler.cc) reset the XID once the transaction is
ended. But those functions wouldn't reset the XID in case of
a empty transaction, leading to a assertion when a new starting
a new XA transaction.
The solution is to ensure that the XID state is reset when empty
transactions are ended (by either commit or rollback). This is
achieved by reorganizing the code so that the transaction cleanup
routine is invoked whenever a transaction is ended.
Problem:
Crash happened with a user-defined utf8 collation,
on attempt to insert a value longer than the column
to store.
Reason:
The "ctype" member was not initialized (NULL) when
allocating a user-defined utf8 collation, so an attempt
to call my_ctype(cs, *str) to check if we loose any important
data when truncating the value made the server crash.
Fix:
Initializing tge "ctype" member to a proper value.
mysql-test/r/ctype_ldml.result
Adding tests
mysql-test/t/ctype_ldml.test
Adding tests
strings/ctype-uca.c
Adding initialization of "ctype" member.
modified:
mysql-test/r/ctype_ldml.result
mysql-test/t/ctype_ldml.test
strings/ctype-uca.c
The crash happens because of uninitialized
lex->ssl_cipher, lex->x509_subject, lex->x509_issuer variables.
The fix is to add initialization of these variables for
stored procedures&functions.
The crash happens due to wrong max_length value which is set on
Item_func_round::fix_length_and_dec() stage. The value is set to
args[0]->max_length which is too big in case of LONGTEXT(LONGBLOB) fields.
The fix is to set max_length using float_length() function.
BEGIN/COMMIT/ROLLBACK was subject to replication db rules, and
caused the boundary of a transaction not recognized correctly
when these queries were ignored by the rules.
Fixed the problem by skipping replication db rules for these
statements.
MySQL crashes if a user without proper privileges attempts to create a procedure.
The crash happens because more than one error state is pushed onto the Diagnostic
area. In this particular case the user is denied to implicitly create a new user
account with the implicitly granted privileges ALTER- and EXECUTE ROUTINE.
The new account is needed if the original user account contained a host mask.
A user account with a host mask is a distinct user account in this context.
An alternative would be to first get the most permissive user account which
include the current user connection and then assign privileges to that
account. This behavior change is considered out of scope for this bug patch.
The implicit assignment of privileges when a user creates a stored routine is a
considered to be a feature for user convenience and as such it is not
a critical operation. Any failure to complete this operation is thus considered
non-fatal (an error becomes a warning).
The patch back ports a stack implementation of the internal error handler interface.
This enables the use of multiple error handlers so that it is possible to intercept
and cancel errors thrown by lower layers. This is needed as a error handler already
is used in the call stack emitting the errors which needs to be converted.
mysqldump --tab still dumped triggers to stdout rather than to
individual tables.
We now append triggers to the .sql file for the corresponding
table.
--events and --routines correspond to a database rather than a
table and will still go to stdout with --tab unless redirected
with --result-file (-r).
old_password() functions
The PASSWORD() and OLD_PASSWORD() functions could lead to
memory reads outside of an internal buffer when used with BLOB
arguments.
String::c_ptr() assumes there is at least one extra byte
in the internally allocated buffer when adding the trailing
'\0'. This, however, may not be the case when a String object
was initialized with externally allocated buffer.
The bug was fixed by adding an additional "length" argument to
make_scrambled_password_323() and make_scrambled_password() in
order to avoid String::c_ptr() calls for
PASSWORD()/OLD_PASSWORD().
However, since the make_scrambled_password[_323] functions are
a part of the client library ABI, the functions with the new
interfaces were implemented with the 'my_' prefix in their
names, with the old functions changed to be wrappers around
the new ones to maintain interface compatibility.
The problem is that the server failed to follow the rule that
every X509 object retrieved using SSL_get_peer_certificate()
must be explicitly freed by X509_free(). This caused a memory
leak for builds linked against OpenSSL where the X509 object
is reference counted -- improper counting will prevent the
object from being destroyed once the session containing the
peer certificate is freed.
The solution is to explicitly free every X509 object used.
HAVING
When calculating GROUP BY the server caches some expressions. It does
that by allocating a string slot (Item_copy_string) and assigning the
value of the expression to it. This effectively means that the result
type of the expression can be changed from whatever it was to a string.
As this substitution takes place after the compile-time result type
calculation for IN but before the run-time type calculations,
it causes the type calculations in the IN function done at run time
to get unexpected results different from what was prepared at compile time.
In the CASE ... WHEN ... THEN ... statement there was a similar problem
and it was solved by artificially adding a STRING argument to the set of
types of the IN/CASE arguments at compile time, so if any of the
arguments of the CASE function changes its type to a string it will
still be covered by the information prepared at compile time.
stop/start slave
When stopping and restarting the slave while it is replicating
temporary tables, the server would crash or raise an assertion
failure. This was due to the fact that although temporary tables are
saved between slave threads restart, the reference to the thread in
use (table->in_use) was not being properly updated when the restart
happened (it would still reference the old/invalid thread instead of
the new one).
This patch addresses this issue by resetting the reference to the new
slave thread on slave thread restart.
