Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.

Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.

Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost. 

The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.

Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.

client/mysqldump.c:
  Pass my_free directly as its signature is compatible with the
  callback type -- which wasn't the case for free_table_ent.

from mysql-next-mr-opt-backporting.

Bug#54515: Crash in opt_range.cc::get_best_group_min_max on 
           SELECT from VIEW with GROUP BY
      
When handling the grouping items in get_best_group_min_max, the
items need to be of type Item_field. In this bug, an ASSERT 
triggered because the item used for grouping was an 
Item_direct_view_ref (i.e., the group column is from a view). 
The fix is to get the real_item since Item_ref* pointing to 
Item_field is ok.

mysql-test/r/select.result:
  Add test for BUG#54515
mysql-test/t/select.test:
  Add test for BUG#54515
sql/opt_range.cc:
  Get the real_item() when processing grouping items in 
  get_best_group_min_max.

from next-mr-bugfixing:
BUG#54682 "set sql_select_limit=0 does not work"; let SQL_SELECT_LIMIT=0
work like it does in 5.1.


mysql-test/suite/sys_vars/r/sql_select_limit_func.result:
  before the fix, the SET would emit a warning (0 being rounded up to 1)
  and SELECTs would return one row.
sql/sys_vars.cc:
  0 is allowed, it means an implicit LIMIT 0 (i.e. no rows returned)

Problem: sha2() reported its result as BINARY

Fix:
- Inheriting Item_func_sha2 from Item_str_ascii_func
- Setting max_length via fix_length_and_charset() 
  instead of direct assignment.
- Adding tests

Problem: Item_copy did not set "fixed", which resulted in DBUG_ASSERT in some cases.
Fix: adding  initialization of the "fixed" member

Adding tests:
  mysql-test/include/ctype_numconv.inc
  mysql-test/r/ctype_binary.result
  mysql-test/r/ctype_cp1251.result
  mysql-test/r/ctype_latin1.result
  mysql-test/r/ctype_ucs.result

Adding initialization of the "fixed" member:
  sql/item.h

The server was not cleaning up dbug allocated memory before
exiting. This is not a real problem, as this memory would be
deallocated anyway. Nonetheless, we improve the mysqlbinlog exit
procedure, wrt to memory book-keeping, when no parameter is
given.

To fix this, we deploy a call to my_thread_end() before the
thread exits, which will also free pending dbug related allocated
blocks.

           value and NO_ZERO_DATE

The problem was that a older version of the error path for a
failed admin statement relied upon a few error conditions being
met in order to access a table handler, the first one being that
the table object pointer was not NULL. Probably due to chance,
in all cases a table object was closed but the reference wasn't
reset, the other conditions didn't evaluate to true. With the
addition of a new check on the error path, the handler started
being dereferenced whenever it was not reset to NULL, causing
problems for code paths which closed the table but didn't reset
the reference.

The solution is to reset the reference whenever a admin statement
fails and the tables are closed.

mysql-test/r/partition_innodb.result:
  Add test case result for Bug#54783
mysql-test/t/partition_innodb.test:
  Add test case for Bug#54783
sql/sql_table.cc:
  In case table recreate failed, set a appropriate result code.
  Reset reference to a closed table object, otherwise the error
  path might attempt to access it.

3245 Vladislav Vaintroub	2010-06-16
      Bug #52959 uint in typedef.h undefined on Windows
      Fix: change uint to "unsigned int"

large-pages option is broken) from next-mr to trunk-bugfixing.

Original revision:
------------------------------------------------------------
revision-id: vvaintroub@mysql.com-20100416134524-y4v27j90p5xvblmy
parent: luis.soares@sun.com-20100416000700-n267ynu77visx31t
committer: Vladislav Vaintroub <vvaintroub@mysql.com>
branch nick: mysql-next-mr-bugfixing
timestamp: Fri 2010-04-16 15:45:24 +0200
message:
  Bug #52716 Large files support is disabled, large-pages option is broken.
  
  Correct typo: large pages option was tied to wrong variable opt_large_files,
  instead of opt_large_pages.
------------------------------------------------------------

Adjusted tests.

mysql-test/r/information_schema.result:
  Adjusted tests.
mysql-test/suite/funcs_1/r/is_engines_myisam.result:
  Adjusted tests.

Fixed MyISAM storage engine comment, so it doesn't anymore
state that MyISAM is default storage engine.

DROP TEMP TABLE

Cset: alfranio.correia@sun.com-20100420091043-4i6ouzozb34hvzhb
introduced a change that made drop temporary table to be always
logged if current statement log format was set to row. This is
fine. However, logging operations, for a "DROP TABLE" statement
in mysql_rm_table_part2, are not protected by first checking if
the mysql_bin_log is open before proceeding to the actual
logging. They only check the dont_log_query variable. This was
actually uncovered by the aforementioned cset and not introduced
by it.

We fix this by extending the condition used in the "if" that
wraps logging operations in mysql_rm_table_part2.

BUG#54872 MBR: replication failure caused by using tmp table inside transaction 
      
Changed criteria to classify a statement as unsafe in order to reduce the
number of spurious warnings. So a statement is classified as unsafe when
there is on-going transaction at any point of the execution if:

1. The mixed statement is about to update a transactional table and
a non-transactional table.

2. The mixed statement is about to update a temporary transactional
table and a non-transactional table.
      
3. The mixed statement is about to update a transactional table and
read from a non-transactional table.

4. The mixed statement is about to update a temporary transactional
table and read from a non-transactional table.

5. The mixed statement is about to update a non-transactional table
and read from a transactional table when the isolation level is
lower than repeatable read.

After updating a transactional table if:

6. The mixed statement is about to update a non-transactional table
and read from a temporary transactional table.
 
7. The mixed statement is about to update a non-transactional table
 and read from a temporary transactional table.

8. The mixed statement is about to update a non-transactionala table
   and read from a temporary non-transactional table.
     
9. The mixed statement is about to update a temporary non-transactional
table and update a non-transactional table.
     
10. The mixed statement is about to update a temporary non-transactional
table and read from a non-transactional table.
     
11. A statement is about to update a non-transactional table and the
option variables.binlog_direct_non_trans_update is OFF.

The reason for this is that locks acquired may not protected a concurrent
transaction of interfering in the current execution and by consequence in
the result. So the patch reduced the number of spurious unsafe warnings.

Besides we fixed a regression caused by BUG#51894, which makes temporary
tables to go into the trx-cache if there is an on-going transaction. In
MIXED mode, the patch for BUG#51894 ignores that the trx-cache may have
updates to temporary non-transactional tables that must be written to the
binary log while rolling back the transaction.
      
So we fix this problem by writing the content of the trx-cache to the
binary log while rolling back a transaction if a non-transactional
temporary table was updated and the binary logging format is MIXED.

mysqld-debug.exe in 5.5.3 on windows

Fix:

- Do not rename PDB, install mysqld.pdb matching 
mysqld-debug.exe into bin\debug subdirectory

- Stack tracing code will now additionally look in 
debug subdirectory of the application directory 
for debug symbols.

- Small cleanup in stacktracing code: link with 
dbghelp rather than load functions dynamically 
at runtime, since dbghelp.dll is always present.

- Install debug binaries with WiX

cmake/install_macros.cmake:
  Add optional COMPONENT and PDB_DESTINATION 
  to INSTALL_DEBUG_TARGET
mysys/stacktrace.c:
  If binary is build with DBUG, also look in debug subdirectory
  of  executable directory. Packaging will put some PDBs there
  (e.g bin\mysqld-debug.exe will have corresponding pdb in 
  bin\debug)
  
  Also some cleanup: do not load dbghelp dynamically, instead
  link with it. dbghelp is present on all Windows starting with 
  XP.
packaging/WiX/CPackWixConfig.cmake:
  Install debug binaries
sql/CMakeLists.txt:
  Do not rename PDB for mysqld-debug.exe, install it in debug subdirectory

switching binlog format to ROW

BUG 52616 fixed the case which the user would switch from STMT to
ROW binlog format, but the server would silently ignore it. After
that fix thd->is_current_stmt_binlog_format_row() reports correct
value at logging time and events are logged in ROW (as expected)
instead of STMT as they were previously and wrongly logged.

However, the fix was only partially complete, because on
disconnect, at THD cleanup, the implicit logging of temporary
tables is conditionally performed. If the binlog_format==ROW and
thd->is_current_stmt_binlog_format_row() is true then DROPs are
not logged. Given that the user can switch from STMT to ROW, this
is wrong because the server cannot tell, just by relying on the
ROW binlog format, that the tables have been dropped before. This
is effectively similar to the MIXED scenario when a switch from
STMT to ROW is triggered.

We fix this by removing this condition from
close_temporary_tables.

mysql-test/extra/binlog_tests/drop_temp_table.test:
  Added binlog test case.
mysql-test/suite/binlog/r/binlog_row_drop_tmp_tbl.result:
  Result changes because:
  - there is a missing drop on three temporary tables
  - it now contains results for the test added
mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result:
  Result now contains the implicit drop for the temporary table.
mysql-test/suite/binlog/r/binlog_stm_drop_tmp_tbl.result:
  Result file changed because it now contains results for added
  test case.
mysql-test/suite/rpl/r/rpl_drop_temp.result:
  Result file changed because it now contains results for added
  test case.
mysql-test/suite/rpl/t/rpl_drop_temp.test:
  Added replication test case.
sql/sql_base.cc:
  Removed the condition that would make the server to skip
  logging implicit drops when ROW binary log format mode was 
  in use.
  Additionally, deployed DBUG_ENTER/RETURN macros.

This bug is a consequence of WL#5349, as the
default storage engine was changed.

The fix was to explicitly add an ENGINE
clause to a CREATE TABLE statement, to
ensure that we test case preservement on
MyISAM.

   Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
 
   The server crashed on an attempt to optimize a MERGE table with
   non-existent child table.
 
   mysql_admin_table() relied on the table to be successfully open
   if a table object had been allocated.
 
   Changed code to check return value of the open function before
   calling a handler:: function on it.

mysql-test/r/merge.result:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
      Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
      Updated result file.
mysql-test/t/merge.test:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
      Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
      Changed tests to respect changed TEMPORARY MERGE locking (unrelated).
      Changed tests to respect changed CREATE TABLE ... LIKE (unrelated).
      Changed tests to respect that no new tables can be created
      under LOCK TABLE (unrelated).
      Added test for Bug#47633.
  Changed error numbers to symbolic names.
  Added test for child locking for ALTER under LOCK TABLE.
  
  Since Bug 36171 is not pushed yet, not the whole patch has been backported.
mysys/my_delete.c:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
      Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
      Fixed error reporting.
      Fixed indentation.
mysys/my_mmap.c:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
      Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
      Added DBUG.
sql/item_func.cc:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
  Added Debug Sync point, required by merge_sync.test.
sql/sql_table.cc:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
      Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
      Do not call handler:: functions if the table was not opened
      successfully.
  Added Debug Sync point, required by merge_sync.test.
storage/myisam/mi_check.c:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
      Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
      Unmap memory before exchanging data files. Needed on Windows.
storage/myisammrg/ha_myisammrg.cc:
  Backport of revid:ingo.struewing@sun.com-20091223200354-r2uzbdkj2v6yv111
  Added Debug Sync point, required by merge_sync.test.
  
  merge_sync.test will be introduced by a patch for Bug 36171,
  which is not pushed yet.

           DML flow and SAVEPOINT

The problem was that replication could break if a transaction involving
both transactional and non-transactional tables was rolled back to a
savepoint. It broke if a concurrent connection tried to drop a
transactional table which was locked after the savepoint was set.
This DROP TABLE completed when ROLLBACK TO SAVEPOINT was executed as the
lock on the table was dropped by the transaction. When the slave later
tried to apply the binlog, it would fail as the table would already
have been dropped.

The reason for the problem is that transactions involving both
transactional and non-transactional tables are written fully to the
binlog during ROLLBACK TO SAVEPOINT. At the same time, metadata locks
acquired after a savepoint, were released during ROLLBACK TO SAVEPOINT.
This allowed a second connection to drop a table only used between
SAVEPOINT and ROLLBACK TO SAVEPOINT. Which caused the transaction binlog
to refer to a non-existing table when it was written during ROLLBACK
TO SAVEPOINT.

This patch fixes the problem by not releasing metadata locks when
ROLLBACK TO SAVEPOINT is executed if binlogging is enabled.

Problem: SQL and IO thread were racing for the IO_CACHE. The former to
flush it, the latter to close it. In some cases this would cause the
SQL thread to lock an invalid IO_CACHE mutex (it had been destroyed by
IO thread). This would happen when SQL thread was initializing the
master.info

Solution: We solve this by locking the log and checking if it is
hot. If it is we keep the log while seeking. Otherwise we release it
right away, because a log can get from hot to cold, but not from cold
to hot.