MDEV-8938 Server Crash on Update with joins
Make unique table check after setup_fields of update because unique table can materialize table and we do not need field resolving after materialization.
Issue:
-----
When a varchar column is used to fill the record in an
internal temporary table, the length of the string stored
in the column is not taken into account. Instead the
default length of packed data is used to copy with memmove.
This will cause valgrind issues since some bytes are
uninitialized.
SOLUTION:
---------
The solution is to take into account the length of the
string stored in the column while filling the record.
This fix is a backport of BUG#13389854.
Issue
-----
This problem occurs when varchar columns are used in a
internal temporary table. The type of the field is set
incorrectly to the generic FIELD_NORMAL type. This in turn
results in an inaccurate calculation of the record length.
Valgrind issues will occur since initialization has not
happend for some bytes.
Fix
----
While creating the temporary table, the type of the field
needs to be to set FIELD_VARCHAR. This will allow myisam
to calculate the record length accurately.
This fix is a backport of BUG#13350136.
2ND EXECUTION OF PS
Description:
------------
When MySQL calls 'EXECUTE stmt' firstly to deal with ORDER BY clause which is
similar with 'ORDER BY 1,(t2a.f2+1)' in find_order_in_list(), it believes the
first expression is a position, the function replaces the pointer of the first
expression with Item_field object associated with a temporary table field,
then releases it after the end of the execution, that behavior destroys the
pointer of first expression.
After that, when MySQL calls 'EXECUTE stmt' once more, the first expression
points to an invalid pointer, so it crashed.
Fix:
----
If an item of ORDER clause is a location, reset 'args' with a original value.
===========
When doing an upgrade, you execute mysql_upgrade. If
mysql_upgrade fails to connect or it connects with a user
without the proper privileges, it will return the error:
FATAL ERROR: Upgrade failed
which is not very informative.
ANALYSIS
========
In main() and check_version_match(), the condition for
errors are clubbed together and throw the same error msg.
The functions need to be splitted up and the corresponding
error msgs have to be displayed.
FIX
===
Splitted the functions and added the specific error msg.
Issue: main.events_1 will fail after 10-10-2015 due
to hardcoded dates specified with events.
Fix: Replace harcoded dates with current dates and offset.
Issue:
======
While re-preparing the statement in
Prepared_statement::swap_prepared_statement for swapping
the database of PS we only swapped the db string but not
its length. This resulted in mismatch between the actual
string and its length. In one particular case where db
of PS was dropped, we have db as null pointer and length
as non-zero. strdup which used above values resulted in
invalid memory access.
Solution:
=========
In Prepared_statement::swap_prepared_statement also swap
db_length along with db variable. Also, remove
DBUG_ASSERT(db_length == copy->db_length) as this have
no meaning if they are 2 different entities.
IMPLEMENTED IN ALL CLIENT PROGRAMS
Description: Option "enable-cleartext-plugin" is not
available for the following client utilities:-
mysqldump
mysqlimport
mysqlshow
mysqlcheck
Analysis: The unavailability of this option limits the
features like PAM authentication from using the above
mentioned utilities.
Fix: Option "enable-cleartext-plugin" is implemented in the
above mentioned client utilities.
CRASHES IN WILD_CASE_COMPARE!
Description:- Executing FLUSH PRIVILEGES and REVOKE/
GRANT concurrently crashes the server.
Analysis:- Concurrent FLUSH PRIVILEGES and REVOKE/GRANT
might trigger a small time frame in which REVOKE/GRANT
fetches the "acl_proxy_user" information as a part of
"acl_check_proxy_grant_access()". Meanwhile FLUSH PRIVILEGES
deletes the old acl structures as a part of "acl_reload()".
After which REVOKE/GRANT tries to access the hostname in
"wild_case_compare()" which leads to a crash because of the
invalid memory access.
Fix:- Mutex lock on "acl_cache" is acquired before fetching
"acl_proxy_user" information in
"acl_check_proxy_grant_access()".
Issue:
======
The fulltext predicate is inside a subquery and involves
an outer reference; it thus cannot be used for FT index look-up,
but MySQL does not see it, which causes a illegal access.
Solution:
=========
Solution is backported from bug#21140088. Outer reference can
not be used as argument of the MATCH function. Added check for
outer reference.
When CHANGE MASTER was executed as a PS, its attributes were wrongly
getting reset toward the end of PREPARE. As a result, the subsequent
executions had no effect. Fixed by making sure that the CHANGE MASTER
attributes are preserved during the lifetime of the PS.
Problem was in rewriting left expression which had 2 references on it. Solved with making subselect reference main.
Item_in_optimized can have not Item_in_subselect reference in left part so type casting with no check is dangerous.
Item::cols() should be checked after Item::fix_fields().
CONVERT_CHARSET_PARTITION_CONSTANT:
SQL/SQL_PARTITION..CC:202
Issue:
-----
This problem happens under the following conditions:
1) A table partitioned with a character column as the key.
2) The expressions specified in the partition definition
requires a charset conversion. This can happen when the
server's default collation is different from the
expression's collation.
3) INSERT DELAYED is used to insert data into the table.
SOLUTION:
---------
While creating the delayed_insert object, initialize it
with the relevant select_lex.
UPDATE VIEW USING OUTER SUBQUERY
Issue:
-----
While resolving a column which refers to a table/view in an
outer query, it's respecitve item object is marked with the
outer query's select_lex object. But when the column refers
to a view or if the column is part of a subquery in the
HAVING clause, an Item_ref object is created. While the
reference to the outer query is stored by the Item_ref
object, the same is not stored in it's real_item.
This creates a problem with the IN-TO-EXISTS optmization.
When there is an index over the column in the inner query,
it will be considered since the column's real_item object
will be mistaken for a local field. This will lead to a
crash.
SOLUTION:
---------
Under the current design, the only way to fix this issue is
to check the reginfo.join_tab for a NULL value. If yes, the
query should not be worrying about the key use.
The testcase and comments added as part of the fix for
Bug#17766653 have been backported.
The test restarts the server and expects that the feedback plugin
will send a report on shutdown, and will write about it in the error
log. But the server is only given 10 sec to shut down properly,
which is not always enough.
Added a parameter to restart_mysqld.inc, and set it to a bigger
value in feedback_plugin_send
The culprit is the feedback_plugin_load test, which is run both separately
and from inside feedback_plugin_send.test. The test queries I_S.FEEDBACK,
and every time it does, 'FEEDBACK used' value is increased.
Fixed by checking that the value is increased instead of recording the actual
value in the result file.
The real problem is that when innodb.xa_recovery test intentionally
crashes the server, system tables can be opened and marked as crashed,
and the next test in line gets blamed for the error which appears
in the error log.
Fixed by flushing the tables before crashing the server
FILE
PROBLEM
In 5.5 when doing doing a rename of a column ,we ignore the case between
old and new column names while comparing them,so if the change is just
the case then we don't even mark the field FIELD_IS_RENAMED ,we just update
the frm file ,but don't recreate the table as is the norm when alter is
used.This leads to inconsistency in the innodb data dictionary which causes
index creation to fail.
FIX
According to the documentation any innodb column rename should trigger
rebuild of the table. Therefore for innodb tables we will do a strcmp()
between the column names and if there is case change in column name
we will trigger a rebuild.
Description: The command FLUSH DES_KEY_FILE is expected to
reload the DES keys from the file that was specified with
the "--des-key-file" option at server startup. But it is not
behaving as expected.
Analysis: The des file reload is defined within a wrong
conditional directive, rendering the command ineffective.
Macro "OPENSSL" was used instead of "HAVE_OPENSSL" macro.
Fix: "OPENSSL" macro is changed to "HAVE_OPENSSL".
Note: Backporting the patch from mysql-5.6.
Problem:
A CREATE TABLE with an invalid table name is detected
at SQL layer. So the table name is reset to an empty
string. But the storage engine is called with this
empty table name. The table name is specified as
"database/table". So, in the given scenario we get
only "database/".
Solution:
Within InnoDB, detect this error and report it to
higher layer.
rb#9274 approved by jimmy.
