- Removed files specific to compiling on OS/2
- Removed files specific to SCO Unix packaging
- Removed "libmysqld/copyright", text is included in documentation
- Removed LaTeX headers for NDB Doxygen documentation
- Removed obsolete NDB files
- Removed "mkisofs" binaries
- Removed the "cvs2cl.pl" script
- Changed a few GPL texts to use "program" instead of "library"
--Bug#52157 various crashes and assertions with multi-table update, stored function
--Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb
--Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846
--Bug#57352 valgrind warnings when creating view
--Recently discovered problem when a nested materialized derived table is used
before being populated and it leads to incorrect result
We have several modes when we should disable subquery evaluation.
The reasons for disabling are different. It could be
uselessness of the evaluation as in case of 'CREATE VIEW'
or 'PREPARE stmt', or we should disable subquery evaluation
if tables are not locked yet as it happens in bug#54475, or
too early evaluation of subqueries can lead to wrong result
as it happened in Bug#19077.
Main problem is that if subquery items are treated as const
they are evaluated in ::fix_fields(), ::fix_length_and_dec()
of the parental items as a lot of these methods have
Item::val_...() calls inside.
We have to make subqueries non-const to prevent unnecessary
subquery evaluation. At the moment we have different methods
for this. Here is a list of these modes:
1. PREPARE stmt;
We use UNCACHEABLE_PREPARE flag.
It is set during parsing in sql_parse.cc, mysql_new_select() for
each SELECT_LEX object and cleared at the end of PREPARE in
sql_prepare.cc, init_stmt_after_parse(). If this flag is set
subquery becomes non-const and evaluation does not happen.
2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which
process FRM files
We use LEX::view_prepare_mode field. We set it before
view preparation and check this flag in
::fix_fields(), ::fix_length_and_dec().
Some bugs are fixed using this approach,
some are not(Bug#57352, Bug#57703). The problem here is
that we have a lot of ::fix_fields(), ::fix_length_and_dec()
where we use Item::val_...() calls for const items.
3. Derived tables with subquery = wrong result(Bug19077)
The reason of this bug is too early subquery evaluation.
It was fixed by adding Item::with_subselect field
The check of this field in appropriate places prevents
const item evaluation if the item have subquery.
The fix for Bug19077 fixes only the problem with
convert_constant_item() function and does not cover
other places(::fix_fields(), ::fix_length_and_dec() again)
where subqueries could be evaluated.
Example:
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
DROP TABLE t1;
4. Derived tables with subquery where subquery
is evaluated before table locking(Bug#54475, Bug#52157)
Suggested solution is following:
-Introduce new field LEX::context_analysis_only with the following
possible flags:
#define CONTEXT_ANALYSIS_ONLY_PREPARE 1
#define CONTEXT_ANALYSIS_ONLY_VIEW 2
#define CONTEXT_ANALYSIS_ONLY_DERIVED 4
-Set/clean these flags when we perform
context analysis operation
-Item_subselect::const_item() returns
result depending on LEX::context_analysis_only.
If context_analysis_only is set then we return
FALSE that means that subquery is non-const.
As all subquery types are wrapped by Item_subselect
it allow as to make subquery non-const when
it's necessary.
SHOW DATABASES LIKE ... was not converting to lowercase on comparison as the
documentation is suggesting.
Fixed it to behave similarly to SHOW TABLES LIKE ... and updated the failing
on MacOSX lowercase_table2 test case.
Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.
strict aliasing violations.
Another rather noisy violation of strict aliasing rules
is the spatial code which makes use of stack-based memory
(of type Geometry_buffer) to provide placement for Geometry
objects. Although a placement new is allowed to dynamically
change the type of a object, the object returned by the
new placement was being ignored and the original stack-based
object was being casted to the new type, thus violating strict
aliasing rules.
The solution is to reorganize the code so that the object
returned by the new placement is used instead of casting the
original object. Also, to ensure that the stack-based object
is properly aligned with respect to the objects it provides
placement for, a set of compiler-dependent macros and types
are introduced so that the alignment of objects can be inquired
and specified.
Although the C standard mandates that sprintf return the number
of bytes written, some very ancient systems (i.e. SunOS 4)
returned a pointer to the buffer instead. Since these systems
are not supported anymore and are hopefully long dead by now,
simply remove the portability wrapper that dealt with this
discrepancy. The autoconf check was causing trouble with GCC.
Since the original fix for this bug lowercases the search pattern it's not a
good idea to copy the search pattern to the output instead of the real table
name found (since, depending on the case mode these two names may differ in
case).
Fixed the infrmation_schema.test failure by making sure the actual table
name of an inoformation schema table is passed instead of the lookup pattern
even when the pattern doesn't contain wildcards.
returns nothing
When looking for table or database names inside INFORMATION_SCHEMA
we must convert the table and database names to lowercase (just as it's
done in the rest of the server) when lowercase_table_names is non-zero.
This will allow us to find the same tables that we would find if there
is no condition.
Fixed by converting to lower case when extracting the database and
table name conditions.
Test case added.
During creation of the table list of
processed tables hidden I_S table 'VARIABLES'
is erroneously added into the table list.
it leads to ER_UNKNOWN_TABLE error in
TABLE_LIST::add_table_to_list() function.
The fix is to skip addition of hidden I_S
tables into the table list.
strict aliasing violations.
One somewhat major source of strict-aliasing violations and
related warnings is the SQL_LIST structure. For example,
consider its member function `link_in_list` which takes
a pointer to pointer of type T (any type) as a pointer to
pointer to unsigned char. Dereferencing this pointer, which
is done to reset the next field, violates strict-aliasing
rules and might cause problems for surrounding code that
uses the next field of the object being added to the list.
The solution is to use templates to parametrize the SQL_LIST
structure in order to deference the pointers with compatible
types. As a side bonus, it becomes possible to remove quite
a few casts related to acessing data members of SQL_LIST.
Analysis showed that in case of accessing I_S table
ROUTINES we perform unnecessary allocations
with get_field() function for every processed row that
in their turn causes significant memory growth.
the fix is to avoid use of get_field().
concurrent I_S query
There were two problem:
1) MYSQL_LOCK_IGNORE_FLUSH also ignored name locks
2) there was a race between abort_and_upgrade_locks and
alter_close_tables
(i.e. remove_table_from_cache and
close_data_files_and_morph_locks)
Which allowed the table to be opened with MYSQL_LOCK_IGNORE_FLUSH flag
resulting in renaming a partition that was already in use,
which could cause the table to be unusable.
Solution was to not allow IGNORE_FLUSH to skip waiting for
a named locked table.
And to not release the LOCK_open mutex between the
calls to remove_table_from_cache and
close_data_files_and_morph_locks by merging the functions
abort_and_upgrade_locks and alter_close_tables.
the fill_schema_processlist function accesses THD::query() without proper protection
so the parallel thread killing can lead to access to the freed meemory.
per-file comments:
sql/sql_load.cc
Bug#51377 Crash in information_schema / processlist on concurrent DDL workload
the THD::set_query_inner() call needs to be protected.
But here we don't need to change the original thd->query() at all.
sql/sql_show.cc
Bug#51377 Crash in information_schema / processlist on concurrent DDL workload
protect the THD::query() access with the THD::LOCK_thd_data mutex.
check_access() returning false for a database does not
guarantee that the access is granted to it.
This wrong condition in filling the INFORMATION_SCHEMA
tables causes extra tables to be returned to the user
even if he has no rights to see them.
Fixed by correcting the condition.
When checking for an error after removing the special view error handler the code
was not taking into account that open_tables() may fail because of the current
statement being killed.
Added a check for thd->killed.
Added a client program to test it.
Implemented the server infrastructure for the fix:
1. Added a function LEX_STRING *thd_query_string(THD) to return
a LEX_STRING structure instead of char *.
This is the function that must be called in innodb instead of
thd_query()
2. Did some encapsulation in THD : aggregated thd_query and
thd_query_length into a LEX_STRING and made accessor and mutator
methods for easy code updating.
3. Updated the server code to use the new methods where applicable.
view definition
During SHOW CREATE VIEW there is no reason to 'anonymize'
errors that name objects that a user does not have access
to. Moreover it was inconsistently implemented. For example
base tables being referenced from a view appear to be ok,
but not views. The manual on the other hand is clear: If a
user has the privileges SELECT and SHOW VIEW, the view
definition is available to that user, period. The fix
changes the behavior to support the manual.
with gcc 4.3.2
This patch fixes a number of GCC warnings about variables used
before initialized. A new macro UNINIT_VAR() is introduced for
use in the variable declaration, and LINT_INIT() usage will be
gradually deprecated. (A workaround is used for g++, pending a
patch for a g++ bug.)
GCC warnings for unused results (attribute warn_unused_result)
for a number of system calls (present at least in later
Ubuntus, where the usual void cast trick doesn't work) are
also fixed.
procedures causes crashes!
The problem of that bugreport was mostly fixed by the
patch for bug 38691.
However, attached test case focused on another crash or
valgrind warning problem: SHOW PROCESSLIST query accesses
freed memory of SP instruction that run in a parallel
connection.
Changes of thd->query/thd->query_length in dangerous
places have been guarded with the per-thread
LOCK_thd_data mutex (the THD::LOCK_delete mutex has been
renamed to THD::LOCK_thd_data).
on SHOW CREATE TRIGGER + MERGE table
Problem: SHOW CREATE TRIGGER erroneously relies on fact
that we have the only underlying table for a trigger
(wrong for merge tables).
Fix: remove erroneous assert().
those keywords do nothing in 5.1 (they are meant for future versions, for example featuring the Maria engine)
so they are here removed from the syntax. Adding those keywords to future versions when needed is:
- WL#5034 "Add TRANSACTIONA=0|1 and PAGE_CHECKSUM=0|1 clauses to CREATE TABLE"
- WL#5037 "New ROW_FORMAT value for CREATE TABLE: PAGE"
"create as select" (innodb table)
Problem: code constructing "CREATE TABLE..." statement
doesn't take into account that current database is not set
in some cases. That may lead to a server crash.
Fix: check if current database is set.
The problem: described in the bug report.
The fix:
--increase buffers where it's necessary
(buffers which are used in stxnmov)
--decrease buffer lengths which are used
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 second patch, fixing more
of the warnings.
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 second patch, fixing more
of the warnings.
the thread->mysys_var parameter should be empty for the idle
embedded-server threads so that working threads can safely free
this memory.
per-file comments:
libmysqld/lib_sql.cc
Bug#43733 Select on processlist let the embedded server crash (concurrent_innodb_safelog)
set thread->mysys_var= 0 after the query is handled
mysql-test/include/concurrent.inc
Bug#43733 Select on processlist let the embedded server crash (concurrent_innodb_safelog)
enable these for the embedded-server mode
sql/sql_show.cc
Bug#43733 Select on processlist let the embedded server crash (concurrent_innodb_safelog)
show thread lock status in the query result
become negative
- merged the fix to 5.1
- extended to cover I_S.PROCESSLIST.TIME
- Changed the column type of I_S.PROCESSLIST.TIME from LOGNLONG
UNSIGNED
to LONG (to match the SHOW PROCESSLIST type)
- Added a test case
seems to become negative
THD::start_time has a dual meaning : it's either the time since the process
entered a given state or is the transaction time returned by e.g. NOW().
This causes problems, as sometimes THD::start_time may be set to a value
that is correct and needed when used as a base for NOW(), but these times
may be arbitrary (SET @@timestamp) or non-local (coming from the master
through the replication feed).
If one such non-local time is set there's no way to return a correct value
for e.g. SHOW PROCESSLIST or SELECT ... FROM INFORMATION_SCHEMA.PROCESSLIST.
Fixed by making the Time column in SHOW PROCESSLIST SIGNED LONG instead of
UNSIGNED LONG and doing the correct conversions.
Note that no reliable test suite can be constructed, since it would require
knowing the local time and can't be achieved by the means of the current test
suite.
