GitLab

           locks on the table

Fixing the partitioning specifics after TRUNCATE TABLE in
bug-42643 was fixed.

Reorganize of code to decrease the size of the giant switch
in mysql_execute_command, and to prepare for future parser
reengineering. Moved code into Sql_statement objects.

Updated patch according to davi's review comments.

libmysqld/CMakeLists.txt:
  Added new files.
libmysqld/Makefile.am:
  Added new files.
mysql-test/r/not_partition.result:
  now returning error on partitioning commands
  if partitioning is not enabled.
mysql-test/r/partition_disabled.result:
  There is no partition handlerton, so it cannot
  find the specified engine in the .frm file.
mysql-test/r/partition_truncate.result:
  Updated test results.
mysql-test/suite/parts/inc/partition_mgm.inc:
  Added check that TRUNCATE PARTITION does not delete on failure.
mysql-test/suite/parts/r/partition_debug_sync_innodb.result:
  updated results.
mysql-test/suite/parts/r/partition_mgm_lc0_archive.result:
  updated results.
mysql-test/suite/parts/r/partition_mgm_lc1_archive.result:
  updated results.
mysql-test/suite/parts/r/partition_mgm_lc2_archive.result:
  updated results.
mysql-test/suite/parts/t/partition_debug_sync_innodb.test:
  Test case for this bug.
mysql-test/t/not_partition.test:
  Added check for TRUNCATE PARTITION without partitioning.
mysql-test/t/partition_truncate.test:
  Added test of TRUNCATE PARTITION on non partitioned table.
sql/CMakeLists.txt:
  Added new files.
sql/Makefile.am:
  Added new files.
sql/datadict.cc:
  Moved out the storage engine check into an own
  function, including assert for lock.
sql/datadict.h:
  added dd_frm_storage_engine.
sql/sql_alter_table.cc:
  moved the code for SQLCOM_ALTER_TABLE in mysql_execute_command
  into its own file, and using the Sql_statement object to
  prepare for future parser reengineering.
sql/sql_alter_table.h:
  Created Sql_statement object for ALTER TABLE.
sql/sql_lex.cc:
  resetting m_stmt.
sql/sql_lex.h:
  Temporary hack for forward declaration of enum_alter_table_change_level.
sql/sql_parse.cc:
  Moved out ALTER/ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE
  from the giant switch into their own Sql_statement
  objects.
sql/sql_parse.h:
  Exporting check_merge_table_access.
sql/sql_partition_admin.cc:
  created Sql_statement for
  ALTER TABLE t ANALYZE/CHECK/OPTIMIZE/REPAIR/TRUNCATE
  PARTITION. To be able to reuse the TABLE equivalents.
sql/sql_partition_admin.h:
  Added Sql_statement of partition admin statements.
sql/sql_table.cc:
  Moved table maintenance code into sql_table_maintenance.cc
sql/sql_table.h:
  Moved table maintenance code into sql_table_maintenance.h
  exporting functions used by sql_table_maintenance.
sql/sql_table_maintenance.cc:
  Moved table maintenance code from sql_table.cc
sql/sql_table_maintenance.h:
  Sql_statement objects for ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE.
  Also declaring the keycache functions.
sql/sql_truncate.cc:
  Moved code from SQLCOM_TRUNCATE in mysql_execute_command into
  Truncate_statement::execute.
  Added check for partitioned table on TRUNCATE PARTITION.
  Moved locking fix for partitioned table into
  Alter_table_truncate_partition::execute.
sql/sql_truncate.h:
  Truncate_statement declaration (sub class of Sql_statement).
sql/sql_yacc.yy:
  Using the new Sql_statment objects.

                        
After BUG#36649, warnings for sub-statements are cleared when a 
new sub-statement is started. This is problematic since it suppresses
warnings for unsafe statements in some cases. It is important that we
always give a warning to the client, because the user needs to know
when there is a risk that the slave goes out of sync.
                        
We fixed the problem by generating warning messages for unsafe statements
while returning from a stored procedure, function, trigger or while
executing a top level statement.
                        
We also started checking unsafeness when both performance and log tables are
used. This is necessary after the performance schema which does a distinction
between performance and log tables.

mysql-test/extra/rpl_tests/create_recursive_construct.inc:
  Changed the order of the calls in the procedure because the code
  that checks if a warning message is printed out expects that the
  first statement gives an warning what is not the case for INSERT
  INTO ta$CRC_ARG_level VALUES (47);
mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
  Updated the result file.
mysql-test/suite/binlog/r/binlog_unsafe.result:
  There are several changes here:
          
  (1) - Changed the CREATE PROCEDURE $CRC.
                                  
  (2) - The procedure $CRC was failing and the content of the binlog
        was being printed out, after fix (1) the failure disappeared.
                                  
  (3) - The warning message for unsafeness due to auto-increment collumns was
        changed.
                                  
  (4) - The warning message for unsafeness due to VERSION(), RAND() was changed.
mysql-test/suite/binlog/t/binlog_stm_unsafe_warning.test:
  Tested filters.
mysql-test/suite/binlog/t/binlog_unsafe.test:
  Reenabled the test case binlog_unsafe.
mysql-test/suite/binlog/t/disabled.def:
  Reenabled the test case binlog_unsafe.
mysql-test/suite/rpl/r/rpl_begin_commit_rollback.result:
  Updated the result file.
mysql-test/suite/rpl/r/rpl_non_direct_stm_mixing_engines.result:
  Updated the result file.
mysql-test/suite/rpl/r/rpl_stm_auto_increment_bug33029.result:
  Updated the result file.
sql/sql_class.cc:
  Moved the stmt_accessed_table_flag variable and related information to the
  LEX as we need the variable reset after each statement even inside a stored
  procedure, what did not happen if the information was in the THD.
          
  Changed the routine in the THD::binlog_query that prints the warning
  messages to avoid trying to print them when inside a stored procedure,
  function or trigger.
                          
  Checked for unsafeness when both performance and log tables where used.
  After the introduction of the performance schema, we need to check both.

/*![:version:] Query Code */, where [:version:] is a sequence of 5 
digits representing the mysql server version(e.g /*!50200 ... */),
is a special comment that the query in it can be executed on those 
servers whose versions are larger than the version appearing in the 
comment. It leads to a security issue when slave's version is larger 
than master's. A malicious user can improve his privileges on slaves. 
Because slave SQL thread is running with SUPER privileges, so it can
execute queries that he/she does not have privileges on master.

This bug is fixed with the logic below: 
- To replace '!' with ' ' in the magic comments which are not applied on
  master. So they become common comments and will not be applied on slave.

- Example:
  'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /*!99999 ,(3)*/
  will be binlogged as
  'INSERT INTO t1 VALUES (1) /*!10000, (2)*/ /* 99999 ,(3)*/

mysql-test/suite/rpl/t/rpl_conditional_comments.test:
  Test the patch for this bug.
sql/mysql_priv.h:
  Rename inBuf as rawBuf and remove the const limitation.
sql/sql_lex.cc:
  To replace '!' with ' ' in the magic comments which are not applied on
  master.
sql/sql_lex.h:
  Remove the const limitation on parameter buff, as it can be modified in the function since
  this patch.
  Add member function yyUnput for Lex_input_stream. It set a character back the query buff.
sql/sql_parse.cc:
  Rename inBuf as rawBuf and remove the const limitation.
sql/sql_partition.cc:
  Remove the const limitation on parameter part_buff, as it can be modified in the function since
  this patch.
sql/sql_partition.h:
  Remove the const limitation on parameter part_buff, as it can be modified in the function since
  this patch.
sql/table.h:
  Remove the const limitation on variable partition_info, as it can be modified since
  this patch.

This patch also fixes Bug#55452 "SET PASSWORD is
replicated twice in RBR mode".

The goal of this patch is to remove the release of 
metadata locks from close_thread_tables().
This is necessary to not mistakenly release
the locks in the course of a multi-step
operation that involves multiple close_thread_tables()
or close_tables_for_reopen().

On the same token, move statement commit outside 
close_thread_tables().

Other cleanups:
Cleanup COM_FIELD_LIST.
Don't call close_thread_tables() in COM_SHUTDOWN -- there
are no open tables there that can be closed (we leave
the locked tables mode in THD destructor, and this
close_thread_tables() won't leave it anyway).

Make open_and_lock_tables() and open_and_lock_tables_derived()
call close_thread_tables() upon failure.
Remove the calls to close_thread_tables() that are now
unnecessary.

Simplify the back off condition in Open_table_context.

Streamline metadata lock handling in LOCK TABLES 
implementation.

Add asserts to ensure correct life cycle of 
statement transaction in a session.

Remove a piece of dead code that has also become redundant
after the fix for Bug 37521.

mysql-test/r/variables.result:
  Update results: set @@autocommit and statement transaction/
  prelocked mode.
mysql-test/r/view.result:
  A harmless change in CHECK TABLE <view> status for a broken view.
  If previously a failure to prelock all functions used in a view 
  would leave the connection in LTM_PRELOCKED mode, now we call
  close_thread_tables() from open_and_lock_tables()
  and leave prelocked mode, thus some check in mysql_admin_table() that
  works only in prelocked/locked tables mode is no longer activated.
mysql-test/suite/rpl/r/rpl_row_implicit_commit_binlog.result:
  Fixed Bug#55452 "SET PASSWORD is replicated twice in
  RBR mode": extra binlog events are gone from the
  binary log.
mysql-test/t/variables.test:
  Add a test case: set autocommit and statement transaction/prelocked
  mode.
sql/event_data_objects.cc:
  Simplify code in Event_job_data::execute().
  Move sp_head memory management to lex_end().
sql/event_db_repository.cc:
  Move the release of metadata locks outside
  close_thread_tables().
  Make sure we call close_thread_tables() when
  open_and_lock_tables() fails and remove extra
  code from the events data dictionary.
  Use close_mysql_tables(), a new internal
  function to properly close mysql.* tables
  in the data dictionary.
  Contract Event_db_repository::drop_events_by_field,
  drop_schema_events into one function.
  When dropping all events in a schema,
  make sure we don't mistakenly release all
  locks acquired by DROP DATABASE. These
  include locks on the database name
  and the global intention exclusive
  metadata lock.
sql/event_db_repository.h:
  Function open_event_table() does not require an instance 
  of Event_db_repository.
sql/events.cc:
  Use close_mysql_tables() instead of close_thread_tables()
  to bootstrap events, since the latter no longer
  releases metadata locks.
sql/ha_ndbcluster.cc:
  - mysql_rm_table_part2 no longer releases
  acquired metadata locks. Do it in the caller.
sql/ha_ndbcluster_binlog.cc:
  Deploy the new protocol for closing thread
  tables in run_query() and ndb_binlog_index
  code.
sql/handler.cc:
  Assert that we never call ha_commit_trans/
  ha_rollback_trans in sub-statement, which
  is now the case.
sql/handler.h:
  Add an accessor to check whether THD_TRANS object
  is empty (has no transaction started).
sql/log.cc:
  Update a comment.
sql/log_event.cc:
  Since now we commit/rollback statement transaction in 
  mysql_execute_command(), we need a mechanism to communicate
  from Query_log_event::do_apply_event() to mysql_execute_command()
  that the statement transaction should be rolled back, not committed.
  Ideally it would be a virtual method of THD. I hesitate
  to make THD a virtual base class in this already large patch.
  Use a thd->variables.option_bits for now.
  
  Remove a call to close_thread_tables() from the slave IO
  thread. It doesn't open any tables, and the protocol
  for closing thread tables is more complicated now.
  
  Make sure we properly close thread tables, however, 
  in Load_data_log_event, which doesn't
  follow the standard server execution procedure
  with mysql_execute_command().
  @todo: this piece should use Server_runnable
  framework instead.
  Remove an unnecessary call to mysql_unlock_tables().
sql/rpl_rli.cc:
  Update Relay_log_info::slave_close_thread_tables()
  to follow the new close protocol.
sql/set_var.cc:
  Remove an unused header.
sql/slave.cc:
  Remove an unnecessary call to
  close_thread_tables().
sql/sp.cc:
  Remove unnecessary calls to close_thread_tables()
  from SP DDL implementation. The tables will
  be closed by the caller, in mysql_execute_command().
  When dropping all routines in a database, make sure
  to not mistakenly drop all metadata locks acquired
  so far, they include the scoped lock on the schema.
sql/sp_head.cc:
  Correct the protocol that closes thread tables
  in an SP instruction.
  Clear lex->sphead before cleaning up lex
  with lex_end to make sure that we don't
  delete the sphead twice. It's considered
  to be "cleaner" and more in line with
  future changes than calling delete lex->sphead
  in other places that cleanup the lex.
sql/sp_head.h:
  When destroying m_lex_keeper of an instruction,
  don't delete the sphead that all lex objects
  share. 
  @todo: don't store a reference to routine's sp_head
  instance in instruction's lex.
sql/sql_acl.cc:
  Don't call close_thread_tables() where the caller will
  do that for us.
  Fix Bug#55452 "SET PASSWORD is replicated twice in RBR 
  mode" by disabling RBR replication in change_password()
  function.
  Use close_mysql_tables() in bootstrap and ACL reload
  code to make sure we release all metadata locks.
sql/sql_base.cc:
  This is the main part of the patch:
  - remove manipulation with thd->transaction
  and thd->mdl_context from close_thread_tables().
  Now this function is only responsible for closing
  tables, nothing else.
  This is necessary to be able to easily use
  close_thread_tables() in procedures, that
  involve multiple open/close tables, which all
  need to be protected continuously by metadata
  locks.
  Add asserts ensuring that TABLE object
  is only used when is protected by a metadata lock.
  Simplify the back off condition of Open_table_context,
  we no longer need to look at the autocommit mode.
  Make open_and_lock_tables() and open_normal_and_derived_tables()
  close thread tables and release metadata locks acquired so-far 
  upon failure. This simplifies their usage.
  Implement close_mysql_tables().
sql/sql_base.h:
  Add declaration for close_mysql_tables().
sql/sql_class.cc:
  Remove a piece of dead code that has also become redundant
  after the fix for Bug 37521.
  The code became dead when my_eof() was made a non-protocol method,
  but a method that merely modifies the diagnostics area.
  The code became redundant with the fix for Bug#37521, when 
  we started to cal close_thread_tables() before
  Protocol::end_statement().
sql/sql_do.cc:
  Do nothing in DO if inside a substatement
  (the assert moved out of trans_rollback_stmt).
sql/sql_handler.cc:
  Add comments.
sql/sql_insert.cc:
  Remove dead code. 
  Release metadata locks explicitly at the
  end of the delayed insert thread.
sql/sql_lex.cc:
  Add destruction of lex->sphead to lex_end(),
  lex "reset" method called at the end of each statement.
sql/sql_parse.cc:
  Move close_thread_tables() and other related
  cleanups to mysql_execute_command()
  from dispatch_command(). This has become
  possible after the fix for Bug#37521.
  Mark federated SERVER statements as DDL.
  
  Next step: make sure that we don't store
  eof packet in the query cache, and move
  the query cache code outside mysql_parse.
  
  Brush up the code of COM_FIELD_LIST.
  Remove unnecessary calls to close_thread_tables().
  
  When killing a query, don't report "OK"
  if it was a suicide.
sql/sql_parse.h:
  Remove declaration of a function that is now static.
sql/sql_partition.cc:
  Remove an unnecessary call to close_thread_tables().
sql/sql_plugin.cc:
  open_and_lock_tables() will clean up
  after itself after a failure.
  Move close_thread_tables() above
  end: label, and replace with close_mysql_tables(),
  which will also release the metadata lock
  on mysql.plugin.
sql/sql_prepare.cc:
  Now that we no longer release locks in close_thread_tables()
  statement prepare code has become more straightforward.
  Remove the now redundant check for thd->killed() (used
  only by the backup project) from Execute_server_runnable.
  Reorder code to take into account that now mysql_execute_command()
  performs lex->unit.cleanup() and close_thread_tables().
sql/sql_priv.h:
  Add a new option to server options to interact
  between the slave SQL thread and execution
  framework (hack). @todo: use a virtual
  method of class THD instead.
sql/sql_servers.cc:
  Due to Bug 25705 replication of 
  DROP/CREATE/ALTER SERVER is broken.
  Make sure at least we do not attempt to 
  replicate these statements using RBR,
  as this violates the assert in close_mysql_tables().
sql/sql_table.cc:
  Do not release metadata locks in mysql_rm_table_part2,
  this is done by the caller.
  Do not call close_thread_tables() in mysql_create_table(),
  this is done by the caller. 
  Fix a bug in DROP TABLE under LOCK TABLES when,
  upon error in wait_while_table_is_used() we would mistakenly
  release the metadata lock on a non-dropped table.
  Explicitly release metadata locks when doing an implicit
  commit.
sql/sql_trigger.cc:
  Now that we delete lex->sphead in lex_end(),
  zero the trigger's sphead in lex after loading
  the trigger, to avoid double deletion.
sql/sql_udf.cc:
  Use close_mysql_tables() instead of close_thread_tables().
sql/sys_vars.cc:
  Remove code added in scope of WL#4284 which would
  break when we perform set @@session.autocommit along
  with setting other variables and using tables or functions.
  A test case added to variables.test.
sql/transaction.cc:
  Add asserts.
sql/tztime.cc:
  Use close_mysql_tables() rather than close_thread_tables().

Remove unused variables.

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.

> ------------------------------------------------------------
> revno: 3362
> revision-id: davi.arnaut@sun.com-20100401131522-895y8uzvv8ag44gs
> parent: ramil@mysql.com-20100429045409-r7r5lcyiruis15v7
> committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
> branch nick: 50755-5.1
> timestamp: Thu 2010-04-01 10:15:22 -0300
> message:
>   Bug#50755: Crash if stored routine def contains version comments
>   
>   The problem was that a syntactically invalid trigger could cause
>   the server to crash when trying to list triggers. The crash would
>   happen due to a mishap in the backup/restore procedure that should
>   protect parser items which are not associated with the trigger. The
>   backup/restore is used to isolate the parse tree (and context) of
>   a statement from the load (and parsing) of a trigger. In this case,
>   a error during the parsing of a trigger could cause the improper
>   backup/restore sequence.
>   
>   The solution is to properly restore the original statement context
>   before the parser is exited due to syntax errors in the trigger body.

            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.

sql/handler.h:
  Use the appropriate template type argument.
sql/item.cc:
  Remove now-unnecessary cast.
sql/item_subselect.cc:
  Remove now-unnecessary casts.
sql/item_sum.cc:
  Use the appropriate template type argument.
  Remove now-unnecessary cast.
sql/mysql_priv.h:
  Move SQL_LIST structure to sql_list.h
  Use the appropriate template type argument.
sql/sp.cc:
  Remove now-unnecessary casts.
sql/sql_delete.cc:
  Use the appropriate template type argument.
  Remove now-unnecessary casts.
sql/sql_derived.cc:
  Remove now-unnecessary casts.
sql/sql_lex.cc:
  Remove now-unnecessary casts.
sql/sql_lex.h:
  SQL_LIST now takes a template type argument which must
  match the type of the elements of the list. Use forward
  declaration when the type is not available, it is used
  in pointers anyway.
sql/sql_list.h:
  Rename SQL_LIST to SQL_I_List. The template parameter is
  the type of object that is stored in the list.
sql/sql_olap.cc:
  Remove now-unnecessary casts.
sql/sql_parse.cc:
  Remove now-unnecessary casts.
sql/sql_prepare.cc:
  Remove now-unnecessary casts.
sql/sql_select.cc:
  Remove now-unnecessary casts.
sql/sql_show.cc:
  Remove now-unnecessary casts.
sql/sql_table.cc:
  Remove now-unnecessary casts.
sql/sql_trigger.cc:
  Remove now-unnecessary casts.
sql/sql_union.cc:
  Remove now-unnecessary casts.
sql/sql_update.cc:
  Remove now-unnecessary casts.
sql/sql_view.cc:
  Remove now-unnecessary casts.
sql/sql_yacc.yy:
  Remove now-unnecessary casts.
storage/myisammrg/ha_myisammrg.cc:
  Remove now-unnecessary casts.

    
1) No mutex and no function call if we're not using
plugins.
2) If we're above the table definition cache limit,
delete the oldest unused share, not the share on our hands.

sql/sql_base.cc:
  If we're above the table definition cache limit,
  delete the oldest unused share, not the share on our hands.
sql/sql_lex.cc:
  No mutex and no function call if we're not using
  plugins.

transactional SELECT and ALTER TABLE ... REBUILD PARTITION".

The goal of this patch is to decouple type of metadata
lock acquired for table by open_tables() from type of
table-level lock to be acquired on it.

To achieve this we change approach to how we determine what
type of metadata lock should be acquired on table to be open.
Now instead of inferring it at open_tables() time from flags
and type of table-level lock we rely on that type of metadata
lock is properly set at parsing time and is not changed
further.

sql/ha_ndbcluster.cc:
  Now one needs to properly initialize table list element's
  MDL_request object before calling mysql_rm_table_part2().
sql/lock.cc:
  lock_table_names() no longer initializes table list elements'
  MDL_request objects. Now proper initialization of these
  requests is a responsibility of the caller.
sql/lock.h:
  Removed MYSQL_OPEN_TAKE_UPGRADABLE_MDL flag which became
  unnecessary. Thanks to the fact that we don't reset type of
  requests for metadata locks between re-executions we now can
  figure out that upgradable locks are requested by simply
  looking at their type which were set in the parser. As result
  this flag became redundant.
sql/mdl.h:
  Added version of new operator which simplifies allocation of
  MDL_request objects on a MEM_ROOT.
sql/sp_head.cc:
  Added comment explaining why it is OK to infer type of
  metadata lock to request from type of table-level lock
  for prelocking.
  Added enum_mdl_type argument to sp_add_to_query_tables()
  to simplify its usage in trigger implementation.
sql/sp_head.h:
  Added enum_mdl_type argument to sp_add_to_query_tables()
  to simplify its usage in trigger implementation.
sql/sql_base.cc:
  - open_table_get_mdl_lock():
    Preserve type of MDL_request for table list element which
    was set in the parser by creating MDL_request objects on
    memory root if MYSQL_OPEN_FORCE_SHARED_MDL or
    MYSQL_OPEN_FORCE_SHARED_HIGH_PRIO_MDL flag were specified.
    Thanks to this and to the fact that we no longer reset
    type of requests for metadata locks between re-executions
    we no longer need to acquire exclusive metadata lock on
    table to be created in a special way. This lock is acquired
    by code handling acquiring of upgradable locks.
    Also changed signature/calling convention for this function
    to simplify its usage.
  - Accordingly special lock strategy for table list elements
    which was used for such locks became unnecessary and was
    removed. Other strategies were renamed.
  - Since we no longer have guarantee that MDL_request object
    which were not satisfied due to lock conflict belongs to
    table list element Open_table_context class and its methods
    were extended to remember pointer to MDL_request which has
    caused problem at request_backoff_action() time and use it
    in recover_from_failed_open(). Similar approach is used
    for cases when problem from which we need to recover is
    not related to MDL but to the table itself. In this case
    we store pointer to the element of table list.
  - Changed open_tables()/open_tables_check_upgradable_mdl()/
    open_tables_acquire_upgradable_mdl() not to rely on
    MYSQL_OPEN_TAKE_UPGRADABLE_MDL flag to understand when
    upgradable metadata locks should be acquired and not to
    infer type of MDL lock from type of table-level lock.
    Instead we assume that type of MDL to be acquired was set
    in the parser (we can do this as type of MDL_request is
    no longer reset between re-executions).
sql/sql_class.h:
  Since we no longer have guarantee that MDL_request object
  which were not satisfied due to lock conflict belongs to
  table list element Open_table_context class and its methods
  were extended to remember pointer to MDL_request which has
  caused problem at request_backoff_action() time and use it
  in recover_from_failed_open(). Similar approach is used
  for cases when problem from which we need to recover is
  not related to MDL but to the table itself. In this case
  we store pointer to the element of table list.
sql/sql_db.cc:
  Now one needs to properly initialize table list element's
  MDL_request object before calling mysql_rm_table_part2()
  or mysql_rename_tables().
sql/sql_lex.cc:
  st_select_lex/st_select_lex_node::add_table_to_list() method
  now has argument which allows specify type of metadata lock
  to be requested for table list element being added.
sql/sql_lex.h:
  - st_select_lex/st_select_lex_node::add_table_to_list()
    method now has argument which specifies type of metadata
    lock to be requested for table list element being added.
    This allows to explicitly set type of MDL lock to be
    acquired for a DDL statement in parser. It is also more
    future-proof than inferring type of MDL request from type
    of table-level lock.
  - Added Yacc_state::m_mdl_type member which specifies which
    type of metadata lock should be requested for tables to be
    added to table list by a grammar rule in cases when the same
    rule is used in several statements requiring different kinds
    of metadata locks.
sql/sql_parse.cc:
  - st_select_lex::add_table_to_list() method now has argument
    which specifies type of metadata lock to be requested for
    table list element being added. This allows to explicitly
    set type of MDL lock to be acquired for a DDL statement in
    parser. It is also more future-proof than inferring type of
    MDL request from type of table-level lock.
  - EXCLUSIVE_DOWNGRADABLE_MDL lock strategy has a new name -
    OTLS_DOWNGRADE_IF_EXISTS.
  - Adjusted LOCK TABLES implementation to the fact that we no
    longer infer type of metadata lock to be acquired from table
    level lock and that type of MDL request is set at parsing.
    And thus MYSQL_OPEN_TAKE_UPGRADABLE_MDL flag became
    unnecessary.
sql/sql_prepare.cc:
  TABLE_LIST's lock strategy SHARED_MDL was renamed to OTLS_NONE
  as now it means that metadata lock should not be changed during
  call to open_table() (if it has been already acquired) and is
  also used for exclusive metadata lock.
sql/sql_show.cc:
  st_select_lex::add_table_to_list() method now has argument
  which specifies type of metadata lock to be requested for
  table list element being added.
sql/sql_table.cc:
  - Adjusted mysql_admin_table()'s code to the fact that
    open_tables() no longer determines what kind of metadata
    lock should be obtained basing on type of table-level
    lock and flags. Instead type of metadata lock for table
    to be open should be set before calling open_tables().
  - Changed mysql_alter_table() code to the facts:
    a) that now it is responsibility of caller to properly
    initalize MDL_request in table list elements before calling
    lock_table_names()
    b) and that MYSQL_OPEN_TAKE_UPGRADABLE_MDL is no longer
    necessary since type of metadata lock to be obtained
    at open_tables() time is set during parsing.
  - Changed code of mysql_recreate_table() to properly set
    type of metadata and table-level lock to be obtained
    by mysql_alter_table() which it calls.
sql/sql_trigger.cc:
  Instead of relying on MYSQL_OPEN_TAKE_UPGRADABLE_MDL flag to
  force open_tables() to take an upgradable lock we now specify
  exact type of lock to be taken when constructing table list
  element for table to be open for CREATE/DROP TRIGGER.
sql/sql_view.cc:
  We no longer use TABLE_LIST::EXCLUSIVE_MDL strategy to force
  open_tables() to take an exclusive metadata lock on view to
  be created. Instead we rely on parser setting proper type of
  metadata lock to request and open_tables() acquiring it.
  This became possible thanks to the fact that we no longer
  reset type of MDL_request between statement re-executions.
sql/sql_yacc.yy:
  Instead of inferring type of MDL_request for table to be
  open from type of table-level lock and flags passed to
  open_tables() we now explicitly specify them at parsing.
  This became possible thanks to the fact that we no longer
  reset type of MDL_request between statement re-executions.
  In future this should allow to decouple type of metadata
  lock from type of table-level lock.
  The only exception to this approach is statements implemented
  through mysql_admin_table() which re-uses same table list
  element several times with different types of table-level
  and metadata locks.
  We now also properly initialize MDL_request objects for table
  list elements which are later passed to lock_table_names()
  function.
sql/table.cc:
  Do not reset type of MDL_request between statement
  re-executions. This became unnecessesary as we no longer
  change type of MDL_request residing in table list element.
  In its turn this change allows to set type of MDL_request
  only once - at parsing time.
sql/table.h:
  Got rid of TABLE_LIST::EXCLUSIVE_MDL lock strategy.
  Now we can specify that we need to acquire exclusive lock
  on table to be processed by open_tables() through setting
  an appropriate type of MDL_request at parsing time (this
  became possible thanks to the fact that we no longer reset
  types of MDL_request's belonging to table list elements
  between statement re-execution).
  Strategy SHARED_MDL was renamed to OTLS_NONE as now it
  means that metadata lock should not be changed during call
  to open_table() (if it has been already acquired) and is
  also used for exclusive metadata lock.
  Strategy EXCLUSIVE_DOWNGRADABLE_MDL was renamed to
  OTLS_DOWNGRADE_IF_EXISTS.

            Item_hex_string::Item_hex_string

The status of memory allocation in the Lex_input_stream (called
from the Parser_state constructor) was not checked which led to
a parser crash in case of the out-of-memory error.

The solution is to introduce new init() member function in
Parser_state and Lex_input_stream so that status of memory
allocation can be returned to the caller.

mysql-test/r/error_simulation.result:
  Added a test case for bug #42064.
mysql-test/t/error_simulation.test:
  Added a test case for bug #42064.
mysys/my_alloc.c:
  Added error injection code for the regression test.
mysys/my_malloc.c:
  Added error injection code for the regression test.
mysys/safemalloc.c:
  Added error injection code for the regression test.
sql/event_data_objects.cc:
  Use the new init() member function of Parser_state and check
  its return value to handle memory allocation failures.
sql/mysqld.cc:
  Added error injection code for the regression test.
sql/sp.cc:
  Use the new init() member function of Parser_state and check
  its return value to handle memory allocation failures.
sql/sql_lex.cc:
  Moved memory allocation from constructor to the separate init()
  member function.
  Added error injection code for the regression test.
sql/sql_lex.h:
  Moved memory allocation from constructor to the separate init()
  member function.
sql/sql_parse.cc:
  Use the new init() member function of Parser_state and check
  its return value to handle memory allocation failures.
sql/sql_partition.cc:
  Use the new init() member function of Parser_state and check
  its return value to handle memory allocation failures.
sql/sql_prepare.cc:
  Use the new init() member function of Parser_state and check
  its return value to handle memory allocation failures.
sql/sql_trigger.cc:
  Use the new init() member function of Parser_state and check
  its return value to handle memory allocation failures.
sql/sql_view.cc:
  Use the new init() member function of Parser_state and check
  its return value to handle memory allocation failures..
sql/thr_malloc.cc:
  Added error injection code for the regression test.

multiquery packet).

Background:

  - a query can contain multiple SQL statements;

  - the server frees resources allocated to process a query when the
    whole query is handled. In other words, resources allocated to process
    one SQL statement from a multi-statement query are freed when all SQL
    statements are handled.

The problem was that the parser allocated a buffer of size of the whole
query for each SQL statement in a multi-statement query. Thus, if a query
had many SQL-statements (so, the query was long), but each SQL statement
was short, ther parser tried to allocate huge amount of memory (number of
small SQL statements * length of the whole query).

The memory was allocated for a so-called "cpp buffer", which is intended to
store pre-processed SQL statement -- SQL text without version specific
comments.

The fix is to allocate memory for the "cpp buffer" once for all SQL
statements (once for a query).

Fix for bug #46947 "Embedded SELECT without FOR UPDATE is
causing a lock", with after-review fixes.

SELECT statements with subqueries referencing InnoDB tables
were acquiring shared locks on rows in these tables when they
were executed in REPEATABLE-READ mode and with statement or
mixed mode binary logging turned on.

This was a regression which were introduced when fixing
bug 39843.

The problem was that for tables belonging to subqueries
parser set TL_READ_DEFAULT as a lock type. In cases when
statement/mixed binary logging at open_tables() time this
type of lock was converted to TL_READ_NO_INSERT lock at
open_tables() time and caused InnoDB engine to acquire
shared locks on reads from these tables. Although in some
cases such behavior was correct (e.g. for subqueries in
DELETE) in case of SELECT it has caused unnecessary locking.

This patch tries to solve this problem by rethinking our
approach to how we handle locking for SELECT and subqueries.
Now we always set TL_READ_DEFAULT lock type for all cases
when we read data. When at open_tables() time this lock
is interpreted as TL_READ_NO_INSERT or TL_READ depending
on whether this statement as a whole or call to function
which uses particular table should be written to the
binary log or not (if yes then statement should be properly
serialized with concurrent statements and stronger lock
should be acquired).

Test coverage is added for both InnoDB and MyISAM.

This patch introduces an "incompatible" change in locking
scheme for subqueries used in SELECT ... FOR UPDATE and
SELECT .. IN SHARE MODE.
In 4.1 the server would use a snapshot InnoDB read for 
subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE
statements, regardless of whether the binary log is on or off.
If the user required a different type of read (i.e. locking read),
he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE
clause for each individual subquery.
On of the patches for 5.0 broke this behaviour (which was not documented
or tested), and started to use locking reads fora all subqueries in SELECT ... 
FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour.

mysql-test/include/check_concurrent_insert.inc:
  Added auxiliary script which allows to check if statement
  reading table allows concurrent inserts in it.
mysql-test/include/check_no_concurrent_insert.inc:
  Added auxiliary script which allows to check that statement
  reading table doesn't allow concurrent inserts in it.
mysql-test/include/check_no_row_lock.inc:
  Added auxiliary script which allows to check if statement
  reading table doesn't take locks on its rows.
mysql-test/include/check_shared_row_lock.inc:
  Added auxiliary script which allows to check if statement
  reading table takes shared locks on some of its rows.
mysql-test/r/bug39022.result:
  After bug #46947 'Embedded SELECT without FOR UPDATE is
  causing a lock' was fixed test case for bug 39022 has to
  be adjusted in order to trigger execution path on which
  original problem was encountered.
mysql-test/r/innodb_mysql_lock2.result:
  Added coverage for handling of locking in various cases when
  we read data from InnoDB tables (includes test case for
  bug #46947 'Embedded SELECT without FOR UPDATE is causing a
  lock').
mysql-test/r/lock_sync.result:
  Added coverage for handling of locking in various cases when
  we read data from MyISAM tables.
mysql-test/t/bug39022.test:
  After bug #46947 'Embedded SELECT without FOR UPDATE is
  causing a lock' was fixed test case for bug 39022 has to
  be adjusted in order to trigger execution path on which
  original problem was encountered.
mysql-test/t/innodb_mysql_lock2.test:
  Added coverage for handling of locking in various cases when
  we read data from InnoDB tables (includes test case for
  bug #46947 'Embedded SELECT without FOR UPDATE is causing a
  lock').
mysql-test/t/lock_sync.test:
  Added coverage for handling of locking in various cases when
  we read data from MyISAM tables.
sql/log_event.cc:
  Since LEX::lock_option member was removed we no longer can
  rely on its value in Load_log_event::print_query() to
  determine that log event correponds to LOAD DATA CONCURRENT
  statement (this was not correct in all situations anyway).
  A new Load_log_event's member was introduced as a replacement.
  It is initialized at event object construction time and
  explicitly indicates whether LOAD DATA was concurrent.
sql/log_event.h:
  Since LEX::lock_option member was removed we no longer can
  rely on its value in Load_log_event::print_query() to
  determine that log event correponds to LOAD DATA CONCURRENT
  statement (this was not correct in all situations anyway).
  A new Load_log_event's member was introduced as a replacement.
  It is initialized at event object construction time and
  explicitly indicates whether LOAD DATA was concurrent.
sql/sp_head.cc:
  sp_head::reset_lex():
    Before parsing substatement reset part of parser state
    which needs this (e.g. set Yacc_state::m_lock_type to
    default value).
sql/sql_acl.cc:
  Since LEX::reset_n_backup_query_tables_list() now also
  resets LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore it in cases
  when while working with proxy Query_table_list we assume
  that LEX::sql_command still corresponds to original SQL
  command being executed (for example, when we are logging
  statement to the binary log while having Query_tables_list
  reset and backed up).
sql/sql_base.cc:
  Changed read_lock_type_for_table() to return a weak TL_READ
  type of lock in cases when we are executing statement which
  won't update tables directly and table doesn't belong to
  statement's prelocking list and thus can't be used by a
  stored function. It is OK to do so since in this case table
  won't be used by statement or function call which will be
  written to the binary log, so serializability requirements
  for it can be relaxed.
  One of results from this change is that SELECTs on InnoDB
  tables no longer takes shared row locks for tables which
  are used in subqueries (i.e. bug #46947 is fixed).
  Another result is that for similar SELECTs on MyISAM tables
  concurrent inserts are allowed.
  In order to implement this change signature of
  read_lock_type_for_table() function was changed to take
  pointers to Query_tables_list and TABLE_LIST objects.
sql/sql_base.h:
  - Function read_lock_type_for_table() now takes pointers
    to Query_tables_list and TABLE_LIST elements as its
    arguments since to correctly determine lock type it needs
    to know what statement is being performed and whether table
    element for which lock type to be determined belongs to
    prelocking list.
sql/sql_lex.cc:
  - Removed LEX::lock_option and st_select_lex::lock_option
    members. Places in parser that were using them now use
    Yacc_state::m_lock_type instead.
  - To emphasize that LEX::sql_command member is used during
    process of opening and locking of tables it was moved to
    Query_tables_list class. It is now reset by
    Query_tables_list::reset_query_tables_list() method.
sql/sql_lex.h:
  - Removed st_select_lex::lock_option member as there is no
    real need for per-SELECT lock type (HIGH_PRIORITY option
    should apply to the whole statement. FOR UPDATE/LOCK IN
    SHARE MODE clauses can be handled without this member).
    The main effect which was achieved by introduction of this
    member, i.e. using TL_READ_DEFAULT lock type for
    subqueries, is now achieved by setting LEX::lock_option
    (or rather its replacement - Yacc_state::m_lock_type) to
    TL_READ_DEFAULT in almost all cases.
  - To emphasize that LEX::sql_command member is used during
    process of opening and locking of tables it was moved to
    Query_tables_list class.
  - Replaced LEX::lock_option with Yacc_state::m_lock_type
    in order to emphasize that this value is relevant only
    during parsing. Unlike for LEX::lock_option the default
    value for Yacc_state::m_lock_type is TL_READ_DEFAULT.
    Note that for cases when it is OK to take a "weak" read
    lock (e.g. simple SELECT) this lock type will be converted
    to TL_READ at open_tables() time. So this change won't
    cause negative change in behavior for such statements.
    OTOH this change ensures that, for example, for SELECTs
    which are used in stored functions TL_READ_NO_INSERT lock
    is taken when necessary and as result calls to such stored
    functions can be written to the binary log with correct
    serialization.
sql/sql_load.cc:
  Load_log_event constructor now requires a parameter that
  indicates whether LOAD DATA is concurrent.
sql/sql_parse.cc:
  LEX::lock_option was replaced with Yacc_state::m_lock_type.
  And instead of resetting the latter implicitly in
  mysql_init_multi_delete() we do it explicitly in the
  places in parser which call this function.
sql/sql_priv.h:
  - To be able more easily distinguish high-priority SELECTs
    in st_select_lex::print() method added flag for
    HIGH_PRIORITY option.
sql/sql_select.cc:
  Changed code not to rely on LEX::lock_option to determine
  that it is high-priority SELECT. It was replaced with
  Yacc_state::m_lock_type which is accessible only at
  parse time. So instead of LEX::lock_option we now rely
  on a newly introduced flag for st_select_lex::options -
  SELECT_HIGH_PRIORITY.
sql/sql_show.cc:
  Since LEX::reset_n_backup_query_tables_list() now also
  resets LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore it in cases
  when while working with proxy Query_table_list we assume
  that LEX::sql_command still corresponds to original SQL
  command being executed.
sql/sql_table.cc:
  Since LEX::reset_query_tables_list() now also resets
  LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore value of this
  member when this method is called by mysql_admin_table(),
  to make this code safe for re-execution.
sql/sql_trigger.cc:
  Since LEX::reset_n_backup_query_tables_list() now also
  resets LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore it in cases
  when while working with proxy Query_table_list we assume
  that LEX::sql_command still corresponds to original SQL
  command being executed (for example, when we are logging
  statement to the binary log while having Query_tables_list
  reset and backed up).
sql/sql_update.cc:
  Function read_lock_type_for_table() now takes pointers
  to Query_tables_list and TABLE_LIST elements as its
  arguments since to correctly determine lock type it needs
  to know what statement is being performed and whether table
  element for which lock type to be determined belongs to
  prelocking list.
sql/sql_yacc.yy:
  - Removed st_select_lex::lock_option member as there is no
    real need for per-SELECT lock type (HIGH_PRIORITY option
    should apply to the whole statement. FOR UPDATE/LOCK IN
    SHARE MODE clauses can be handled without this member).
    The main effect which was achieved by introduction of this
    member, i.e. using TL_READ_DEFAULT lock type for
    subqueries, is now achieved by setting LEX::lock_option
    (or rather its replacement - Yacc_state::m_lock_type) to
    TL_READ_DEFAULT in almost all cases.
  - Replaced LEX::lock_option with Yacc_state::m_lock_type
    in order to emphasize that this value is relevant only
    during parsing. Unlike for LEX::lock_option the default
    value for Yacc_state::m_lock_type is TL_READ_DEFAULT.
    Note that for cases when it is OK to take a "weak" read
    lock (e.g. simple SELECT) this lock type will be converted
    to TL_READ at open_tables() time. So this change won't
    cause negative change in behavior for such statements.
    OTOH this change ensures that, for example, for SELECTs
    which are used in stored functions TL_READ_NO_INSERT lock
    is taken when necessary and as result calls to such stored
    functions can be written to the binary log with correct
    serialization.
  - To be able more easily distinguish high-priority SELECTs
    in st_select_lex::print() method we now use new flag
    in st_select_lex::options bit-field.

The problem was that a syntactically invalid trigger could cause
the server to crash when trying to list triggers. The crash would
happen due to a mishap in the backup/restore procedure that should
protect parser items which are not associated with the trigger. The
backup/restore is used to isolate the parse tree (and context) of
a statement from the load (and parsing) of a trigger. In this case,
a error during the parsing of a trigger could cause the improper
backup/restore sequence.

The solution is to properly restore the original statement context
before the parser is exited due to syntax errors in the trigger body.

mysql-test/r/trigger.result:
  Add test case result for Bug#50755
mysql-test/t/trigger.test:
  Add test case for Bug#50755
sql/sp_head.cc:
  Merge sp_head::destroy() and sp_head destructor. Retrieve THD
  from the LEX so that m_thd is not necessary.
sql/sql_lex.cc:
  Explicitly restore the original environment.

This patch:

- Moves all definitions from the mysql_priv.h file into
  header files for the component where the variable is
  defined
- Creates header files if the component lacks one
- Eliminates all include directives from mysql_priv.h
- Eliminates all circular include cycles
- Rename time.cc to sql_time.cc
- Rename mysql_priv.h to sql_priv.h

BUG#46364 introduced the flag binlog_direct_non_transactional_updates which
would make N-changes to be written to the binary log upon committing the
statement when "ON". On the other hand, when "OFF" the option was supposed
to mimic the behavior in 5.1. However, the implementation was not mimicking
the behavior correctly and the following bugs popped up:

  Case #1: N-changes executed within a transaction would go into
           the S-cache. When later in the same transaction a
           T-change occurs, N-changes following it were written
           to the T-cache instead of the S-cache. In some cases,
           this raises problems. For example, a
           Table_map_log_event being written initially into the
           S-cache, together with the initial N-changes, would be
           absent from the T-cache. This would log N-changes
           orphaned from a Table_map_log_event (thence discarded
           at the slave). (MIXED and ROW)

   Case #2: When rolling back a transaction, the N-changes that
            might be in the T-cache were disregarded and
            truncated along with the T-changes. (MIXED and ROW)

   Case #3: When a MIXED statement (TN) is ahead of any other
            T-changes in the transaction and it fails, it is kept
            in the T-cache until the transaction ends. This is
            not the case in 5.1 or Betony (5.5.2). In these, the
            failed TN statement would be written to the binlog at
            the same instant it had failed and not deferred until
            transaction end. (SBR)

To fix these problems, we have decided to do what follows:

   For Case #1 and #2, we circumvent them:

      1. by not letting binlog_direct_non_transactional_updates
         affect MIXED and RBR. These modes will keep the behavior
         provided by WL#2687. Although this will make Celosia to
         behave differently from 5.1, an execution will be always
         safe under such modes in the sense that slaves will never
         go out sync. In 5.1, using either MIXED or ROW while
         mixing N-statements and T-statements was not safe.

   For Case #3, we don't actually fix it. We:

      1. keep it and make all MIXED statements whether they end
         up failing or not or whether they are up front in the
         transaction or after some transactional change to always
         be stored in the T-cache. This means that it is written
         to the binary log on transaction commit/rollback only.

      2. We make the warning message even more specific about the
         MIXED statement and SBR.

mysql-test/extra/rpl_tests/rpl_mixing_engines.test:
  Updated the test case to avoid checking inconsistencies between the master and slave
  when session.binlog_direct_non_transactional_updates is ON and the format is statement.
  
  In this scenario, they will diverge because a counter (within a triger) is incremented
  and associated to the issued statement. However, an n-statement is logged ahead of
  the transaction and thus is not executed by the same order in the slave and thus gets
  a different value from the counter.
mysql-test/suite/binlog/r/binlog_multi_engine.result:
  Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result:
  Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
mysql-test/suite/ndb/r/ndb_binlog_format.result:
  Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
mysql-test/suite/rpl/r/rpl_concurrency_error.result:
  Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
mysql-test/suite/rpl/r/rpl_stm_binlog_max_cache_size.result:
  Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
mysql-test/suite/rpl/r/rpl_stm_mixing_engines.result:
  Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
mysql-test/suite/rpl/r/rpl_stm_stop_middle_group.result:
  Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
sql/log.cc:
  Checked if either a trx-cache or a non-trx-cache should be used. 
  
  If bin_log_direct_non_trans_update is active or the format is either
  MIXED or ROW, the cache to be used depends on the flag is_transactional.
  
  When the format is STMT, the non-trx-cache should be used if the statement
  is non-transactional and the trx-cache is empty, i.e. if any transactional
  statement has not committed yet. Otherwise, the trx-cache should be used.
sql/share/errmsg-utf8.txt:
  Added the new unsafe error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
sql/sql_class.cc:
  Started printing ER_BINLOG_UNSAFE_MIXED_STATEMENT, when there
  is a mixed-statement.
  
  Organized the names of the variables and added comments.
sql/sql_lex.cc:
  Added the new unsafe error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
sql/sql_lex.h:
  Added the new unsafe error ER_BINLOG_UNSAFE_MIXED_STATEMENT.

Reading from a self-logging engine and updating a transactional engine such as Innodb
generates changes that are written to the binary log in the statement format and may
make slaves diverge. In the mixed mode, such changes should be written to the binary
log in the row format.

Note that the issue does not happen if we mix a self-logging engine and MyIsam
as this case is caught by checking the mixture of non-transactional and transactional
engines.

So, we classify a mixed statement where one reads from NDB and writes into another 
engine as unsafe:

if (multi_engine && flags_some_set & HA_HAS_OWN_BINLOGGING)
  lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE);

mysql-test/suite/rpl_ndb/r/rpl_ndb_mixed_engines_transactions.result:
  Augmented test case to check mixed statements
mysql-test/suite/rpl_ndb/t/rpl_ndb_mixed_engines_transactions.test:
  Augmented test case to check mixed statements
sql/share/errmsg-utf8.txt:
  Added ER_BINLOG_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE
sql/sql_class.cc:
  Redefined flags' name in order to have two sets of flags: (i) flags that are checked when there
  is a write operation; (ii) flags that are checked regardless of the type of the operation.
  
  Classified a mixed statement where one reads from NDB and writes into another engine as unsafe:
  
    if (multi_engine && flags_some_set & HA_HAS_OWN_BINLOGGING)
      lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE);
sql/sql_lex.cc:
  Added error ER_BINLOG_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE
sql/sql_lex.h:
  Added BINLOG_STMT_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE

Grouping by a subquery in a query with a distinct aggregate
function lead to a wrong result (wrong and unordered
grouping values).

There are two related problems:

1) The query like this:

   SELECT (SELECT t1.a) aa, COUNT(DISTINCT b) c
   FROM t1 GROUP BY aa

returned wrong result, because the outer reference "t1.a"
in the subquery was substituted with the Item_ref item.

The Item_ref item obtains data from the result_field object
that refreshes once after the end of each group. This data
is not applicable to filesort since filesort() doesn't care
about groups (and doesn't update result_field objects with
copy_fields() and so on). Also that data is not applicable
to group separation algorithm: end_send_group() checks every
record with test_if_group_changed() that evaluates Item_ref
items, but it refreshes those Item_ref-s only after the end
of group, that is a vicious circle and the grouped column
values in the output are shifted.

Fix: if
       a) we grouping by a subquery and
       b) that subquery has outer references to FROM list
          of the grouping query,
     then we substitute these outer references with
     Item_direct_ref like references under aggregate
     functions: Item_direct_ref obtains data directly
     from the current record.

2) The query with a non-trivial grouping expression like:

   SELECT (SELECT t1.a) aa, COUNT(DISTINCT b) c
   FROM t1 GROUP BY aa+0

also returned wrong result, since JOIN::exec() substitutes
references to top-level aliases in SELECT list with Item_copy
caching items. Item_copy items have same refreshing policy
as Item_ref items, so the whole groping expression with
Item_copy inside returns wrong result in filesort() and
end_send_group().

Fix: include aliased items into GROUP BY item tree instead
     of Item_ref references to them.



mysql-test/r/group_by.result:
  Test case for bug #45640
mysql-test/t/group_by.test:
  Test case for bug #45640
sql/item.cc:
  Bug #45640: optimizer bug produces wrong results
  
  Item_field::fix_fields() has been modified to resolve
  aliases in GROUP BY item trees into aliased items instead
  of Item_ref items.
sql/item.h:
  Bug #45640: optimizer bug produces wrong results
  
  - Item::find_item_processor() has been introduced.
  - Item_ref::walk() has been modified to apply processors
    to itself too (not only to referenced item).
sql/mysql_priv.h:
  Bug #45640: optimizer bug produces wrong results
  
  fix_inner_refs() has been modified to accept group_list
  parameter.
sql/sql_lex.cc:
  Bug #45640: optimizer bug produces wrong results
  
  Initialization of st_select_lex::group_fix_field has
  been added.
sql/sql_lex.h:
  Bug #45640: optimizer bug produces wrong results
  
  The st_select_lex::group_fix_field field has been introduced
  to control alias resolution in Itef_fied::fix_fields.
sql/sql_select.cc:
  Bug #45640: optimizer bug produces wrong results
  
  - The fix_inner_refs function has been modified to treat
    subquery outer references like outer fields under aggregate
    functions, if they are included in GROUP BY item tree.
  
  - The find_order_in_list function has been modified to
    fix Item_field alias fields included in the GROUP BY item
    trees in a special manner.

The auto-inc unsafe warning makes sense even though it's just
one auto-inc table could be involved via a trigger or a stored
function.
However its content was not updated by bug@45677 fixes continuing to mention
two tables whereas the fixes refined semantics of replication of auto_increment 
in stored routine.

Fixed with updating the error message, renaming the error and an internal unsafe-condition 
constants.

A documentation notice
======================

      Inserting into an autoincrement column in a stored function or a trigger
      is unsafe for replication.
      Even with just one autoincrement column, if the routine is invoked more than 
      once slave is not guaranteed to execute the statement graph same way as 
      the master.
      And since it's impossible to estimate how many times a routine can be invoked at 
      the query pre-execution phase (see lock_tables), the statement is marked
      pessimistically unsafe. 



mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
  results updated to include the expected unsafe warning.
mysql-test/suite/binlog/t/binlog_stm_unsafe_warning.test:
  regression test for bug#50192 to diplaying the unsafe warning comes out to the user warning stack.
sql/share/errmsg-utf8.txt:
  Updating the auto-inc unsafe message to correspond to bug@45677 fixes' new sematics.
sql/share/errmsg.txt:
  Updating the auto-inc unsafe message to correspond to bug@45677 fixes' new sematics.
sql/sql_base.cc:
  changing a symbolic name to correspond to updated by bug@45677 fixes new sematics.
sql/sql_lex.cc:
  changing a symbolic name to correspond to updated by bug@45677 fixes new sematics.
sql/sql_lex.h:
  changing a symbolic name to correspond to updated by bug@45677 fixes new sematics
  and description comments.

sql/sql_base.cc:
  Query_arena *arena and backup are both unused.
  Removing those, allows us to remove select_lex->conds_processed_with_permanent_arena
sql/sql_lex.cc:
  conds_processed_with_permanent_arena is unused
sql/sql_lex.h:
  conds_processed_with_permanent_arena was unused

Non-transactional updates that take place inside a transaction present problems
for logging because they are visible to other clients before the transaction
is committed, and they are not rolled back even if the transaction is rolled
back. It is not always possible to log correctly in statement format when both
transactional and non-transactional tables are used in the same transaction.

In the current patch, we ensure that such scenario is completely safe under the
ROW and MIXED modes.

Backport for 5.5

The root cause of this bug is that the grammar for GROUP BY clauses,
when using WITH CUBE or WITH ROLLUP, cause conflicts with the grammar
for VIEW, when using WITH CHECK OPTION.

The solution is to implement two token look ahead when parsing a WITH token,
to disambiguate the non standard WITH CUBE and WITH ROLLUP syntaxes.

Patch based on code from Marc Alff and Antony Curtis

2630.39.1, 2630.28.29, 2630.34.3, 2630.34.2, 2630.34.1, 2630.29.29,
2630.29.28, 2630.31.1, 2630.28.13, 2630.28.10, 2617.23.14 and
some other minor revisions.

This patch implements: 

WL#4264 "Backup: Stabilize Service Interface" -- all the
server prerequisites except si_objects.{h,cc} themselves (they can
be just copied over, when needed).

WL#4435: Support OUT-parameters in prepared statements.

(and all issues in the initial patches for these two
tasks, that were discovered in pushbuild and during testing).

Bug#39519: mysql_stmt_close() should flush all data
associated with the statement.

After execution of a prepared statement, send OUT parameters of the invoked
stored procedure, if any, to the client.

When using the binary protocol, send the parameters in an additional result
set over the wire.  When using the text protocol, assign out parameters to
the user variables from the CALL(@var1, @var2, ...) specification.

The following refactoring has been made:
  - Protocol::send_fields() was renamed to Protocol::send_result_set_metadata();
  - A new Protocol::send_result_set_row() was introduced to incapsulate
    common functionality for sending row data.
  - Signature of Protocol::prepare_for_send() was changed: this operation
    does not need a list of items, the number of items is fully sufficient.

The following backward incompatible changes have been made:
  - CLIENT_MULTI_RESULTS is now enabled by default in the client;
  - CLIENT_PS_MULTI_RESUTLS is now enabled by default in the client.

include/mysql.h:
  Add a new flag to MYSQL_METHODS::flush_use_result
  function pointer. This flag determines if all results
  should be flushed or only the first one:
      
  - if flush_all_results is TRUE, then cli_flush_use_result()
    will read/flush all pending results. I.e. it will read
    all packets while server status attribute indicates that
    there are more results. This is a new semantic, required
    to fix the bug.
              
  - if flush_all_results is FALSE, the old sematic
    is preserved -- i.e. cli_flush_use_result() reads data
    until first EOF-packet.
include/mysql.h.pp:
  Update the ABI with new calls (compatible changes).
include/mysql_com.h:
  Add CLIENT_PS_OUT_PARAMS -- a client capability indicating that the client supportsю
libmysql/libmysql.c:
  Add mysql_stmt_next_result() -- analogue of mysql_next_result() for binary protocol.
  Fix a minor bug in alloc_fields() -- not all members were copied over,
  and some only shallow-copied (catalog).
  Flush all results in mysql_stmt_close() (Bug#39519).
libmysqld/lib_sql.cc:
  Rename send_fields() -> send_result_set_metadata().
  Refactoring: change prepare_for_send() so that it accepts only 
  what it really needs -- a number of elements in the list.
mysql-test/r/ps.result:
  Update results: WL#4435.
mysql-test/t/ps.test:
  WL#4435: A test case for an SQL-part of the problem.
sql-common/client.c:
  Bug#39519.
  Implement new functionality in cli_flush_use_result():
  if flush_all_delete is TRUE, then it should read/flush
  all pending results.
sql/Makefile.am:
  Add a new header sql_prepare.h to the list
  of build headers.
sql/events.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/handler.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/mysql_priv.h:
  Move sql_prepare.cc-specific declarations to a new
  header - sql_prepare.h.
sql/procedure.h:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/protocol.cc:
  Move the logic responsible for sending of one result
  set row to the Protocol class. Define a template
  for end-of-statement action. 
  Refactoring: change prepare_for_send() so that it accepts 
  only what it really needs -- a number of elements in the list.
  Rename send_fields() to send_result_set_metadata().
sql/protocol.h:
  Update with new declarations (WL#4435).
  Rename send_fields() -> send_result_set_metadata().
  prepare_for_send() only needs the number of columns to send,
  and doesn't use the item list - update signature to require
  only what's needed.
  Add a new protocol type -- Protocol_local.
sql/repl_failsafe.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/slave.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_acl.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_base.cc:
  Include sql_prepare.h (for Reprepare_observer).
sql/sql_cache.cc:
  Extend the query cache flags block to be able
  to store a numeric id for the result format,
  not just a flag binary/non-binary.
sql/sql_class.cc:
  Update to use the rename of Protocol::send_fields()
  to Protocol::send_result_set_metadata().
  Use Protocol::send_one_result_set_row().
sql/sql_class.h:
  Move the declaration of Reprepare_observer to the 
  new header - sql_prepare.h.
  Update to the new signature of class Protocol::send_fields().
sql/sql_connect.cc:
  Use a protocol template method instead of
  raw NET layer API at the end of a statement.
sql/sql_cursor.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_error.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_handler.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
  Use new method Protocol::send_one_result_set_row().
sql/sql_help.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_lex.cc:
  Initialize multi_statements variable.
  Add a handy constant for empty lex
  string.
sql/sql_lex.h:
  Add a separate member for a standalone
  parsing option - multi-statements support.
sql/sql_list.cc:
  sql_list.h is a standalone header now, 
  no need to include mysql_priv.h.
sql/sql_list.h:
  Make sql_list.h a stand-alone header.
sql/sql_parse.cc:
  Include sql_prepare.h for prepared
  statements- related declarations.
  Use a new Protocol template method to end
  each statement (send OK, EOF or ERROR to
  the client).
sql/sql_prepare.cc:
  Implement Execute Direct API (WL#4264), 
  currently unused. It will be used by the service
  interface (Backup).
  Use a new header - sql_prepare.h.
  Add support for OUT parameters in the 
  binary and text protocol (prepared statements 
  only).
sql/sql_prepare.h:
  Add a new header to contain (for now)
  all prepared statement- external
  related declarations.
sql/sql_profile.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_repl.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_select.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_show.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_string.h:
  Add a way to convert a String to LEX_STRING.
sql/sql_table.cc:
  Rename: Protocol::send_fields() -> 
  Protocol::send_result_set_metadata().
sql/sql_update.cc:
  Remove an extraneous my_error(). The error
  is already reported in update_non_unique_table_error().
sql/sql_yacc.yy:
  Support for multi-statements is an independent
  property of parsing, not derived from 
  the protocol type.
tests/mysql_client_test.c:
  Add tests for WL#4435 (binary protocol).

----------------------------------------------------------
revno: 2617.22.5
committer: Konstantin Osipov <kostja@sun.com>
branch nick: mysql-6.0-runtime
timestamp: Tue 2009-01-27 05:08:48 +0300
message:
  Remove non-prefixed use of HASH.
  Always use my_hash_init(), my_hash_inited(), my_hash_search(),
  my_hash_element(), my_hash_delete(), my_hash_free() rather
  than non-prefixed counterparts (hash_init(), etc).
  Remove the backward-compatible defines.

Post-push fix.
Problem: After the original bugfix, if a statement is unsafe,
binlog_format=mixed, and engine is statement-only, a warning was
generated and the statement executed. However, it is a fundamental
principle of binlogging that binlog_format=mixed should guarantee
correct logging, no compromise. So correct behavior is to generate
an error and don't execute the statement.
Fix: Generate error instead of warning.
Since issue_unsafe_warnings can only generate one error message,
this allows us to simplify the code a bit too:
decide_logging_format does not have to save the error code for
issue_unsafe_warnings


mysql-test/suite/binlog/r/binlog_statement_insert_delayed.result:
  updated result file
mysql-test/suite/binlog/r/binlog_stm_ps.result:
  updated result file
mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
  updated result file
mysql-test/suite/binlog/r/binlog_unsafe.result:
  updated result file
mysql-test/suite/rpl/r/rpl_stm_found_rows.result:
  updated result file
mysql-test/suite/rpl/r/rpl_stm_loadfile.result:
  updated result file
mysql-test/suite/rpl_ndb/r/rpl_ndb_binlog_format_errors.result:
  updated result file
mysql-test/suite/rpl_ndb/t/rpl_ndb_binlog_format_errors.test:
  updated test:
   - ER_BINLOG_UNSAFE_AND_STMT_ENGINE is now an error.
   - added test for multiple types of unsafety
sql/share/errmsg.txt:
   - Reformulated ER_BINLOG_UNSAFE_AND_STMT_ENGINE to reflect that it
     is now an error, not a warning.
   - Added "Reason for unsafeness" to ER_BINLOG_UNSAFE_STATEMENT and
     ER_BINLOG_UNSAFE_AND_STMT_ENGINE.
sql/sql_class.cc:
  In decide_logging_format:
   - generate an error immediately in case 3, instead of scheduling a
     warning to be generated later. also updated comments accordingly
   - in case 7, there is only one unsafe warning error code now, so we
     don't need to store it in binlog_unsafe_warning_flags
     (see changes in sql_lex.h)
   - fixed compilation warning in DBUG_PRINT
  
  In issue_binlog_warning:
   - moved array of error codes to sql_lex.h (so that they are
     accessible also from decide_logging_format)
   - simplified code after the first set of bits in
     binlog_unsafe_warning_flags was removed
sql/sql_class.h:
   - got rid of enum_binlog_stmt_warning. It's not needed anymore
     since we only have one type of unsafe warning (one of them
     turned into an error)
   - updated comments accordingly
sql/sql_lex.cc:
  added initialization of the array of error codes that has been
  moved from THD::issue_unsafe_warnings to LEX.
sql/sql_lex.h:
  Moved array of error codes from THD::issue_unsafe_warnings to LEX.

----------------------------------------------------------
revno: 2630.22.8
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-runtime
timestamp: Sun 2008-08-10 18:49:52 +0400
message:
  Get rid of typedef struct for the most commonly used types:
  TABLE, TABLE_SHARE, LEX. This simplifies use of tags
  and forward declarations.

storing and restoring information about foreign keys in the .FRM files and
properly displaying it in SHOW CREATE TABLE output and I_S tables.

The idea of this patch is to change type of Key_part_spec::field_name and
Key::name to LEX_STRING in order to avoid extra strlen() calls during
semantic analysis and statement execution, particularly, in code to be
implemented on the 2nd milestone of WL#148.

Note that since we are not using LEX_STRING everywhere yet (e.g. in
Create_field and KEY) and we want to limit scope of our changes we
have to do strlen() in places where we create Key and Key_part_spec
instances from objects using plain (char*) for strings. These calls
will go away during the process of further (char*) -> LEX_STRING
refactoring.

We have introduced these changes in 6.0 and backported them to 5.5
tree to make people aware of these changes as early as possible and
to simplify merges with mysql-fk and mysql-6.1-fk trees.

No test case is needed since this patch does not introduce any
user visible changes.

sql/sql_class.cc:
  Key_part_spec::field_name is now LEX_STRING. Adjusted code accordingly.
sql/sql_class.h:
  Changed type of Key_part_spec::field_name and Key::name to LEX_STRING in
  order to avoid extra strlen() calls in code responsible for semantic
  analysis and statement execution (e.g. in future code responsible for
  saving/restoring info about foreign keys).
sql/sql_lex.cc:
  Moved null_lex_str from sql_yacc.yy to sql_lex.cc and added its
  declaration to sql_lex.h to make it accessible in other SQL-layer
  modules (e.g. sql_parse.cc).
sql/sql_lex.h:
  Made null_lex_str accessible from outside of sql_lex.cc.
sql/sql_parse.cc:
  Key_part_spec::field_name and Key::name are now LEX_STRING. Adjusted
  code accordingly.
sql/sql_table.cc:
  Adjusted code to accomodate change of type to LEX_STRING for
  Key_part_spec::field_name and Key::name.
sql/sql_yacc.yy:
  Now Key::name and Key_part_spec::field_name are LEX_STRINGs. Adjusted
  grammar to be able properly initialize them. This should allow us to
  save on some strlen() calls during later stages of statement execution.

Changed all no_ to num_ to avoid strange names like no_list_values which is not expected to be number of list values, rather a boolea indicating no list values

with gcc 4.3.2
      
This is the fifth patch cleaning up more GCC warnings about
variables used before initialized using the new macro
UNINIT_VAR().

WL#3352, Introducing Column list partitioning, makes it possible to partition on most data types, makes it possible to prune on multi-field partitioning

The problem is that the lexer could inadvertently skip over the
end of a query being parsed if it encountered a malformed multibyte
character. A specially crated query string could cause the lexer
to jump up to six bytes past the end of the query buffer. Another
problem was that the laxer could use unfiltered user input as
a signed array index for the parser maps (having upper and lower
bounds 0 and 256 respectively).

The solution is to ensure that the lexer only skips over well-formed
multibyte characters and that the index value of the parser maps
is always a unsigned value.

mysql-test/r/ctype_recoding.result:
  Update test case result: ending backtick is not skipped over anymore.
sql/sql_lex.cc:
  Characters being analyzed must be unsigned as they can be
  used as indexes for the parser maps. Only skip over if the
  string is a valid multi-byte sequence.
tests/mysql_client_test.c:
  Add test case for Bug#45010

> ------------------------------------------------------------
> revno: 2852.2.3
> revision-id: davi.arnaut@sun.com-20090403194600-60ufn0tz1gx1kl0l
> parent: gni@mysql.com-20090403184200-vnjtpsv4an79w8bu
> parent: davi.arnaut@sun.com-20090403191154-0ho2nai3chjsmpof
> committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
> branch nick: 43230-5.1
> timestamp: Fri 2009-04-03 16:46:00 -0300
> message:
>   Merge Bug#43230 into mysql-5.1-bugteam
>     ------------------------------------------------------------
>     revno: 1810.3855.16
>     revision-id: davi.arnaut@sun.com-20090403191154-0ho2nai3chjsmpof
>     parent: chad@mysql.com-20090402152928-3ld60a56h86njcpg
>     committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
>     branch nick: 43230-5.0
>     timestamp: Fri 2009-04-03 16:11:54 -0300
>     message:
>       Bug#43230: SELECT ... FOR UPDATE can hang with FLUSH TABLES WITH READ LOCK indefinitely
>       
>       The problem is that a SELECT .. FOR UPDATE statement might open
>       a table and later wait for a impeding global read lock without
>       noticing whether it is holding a table that is being waited upon
>       the the flush phase of the process that took the global read
>       lock.
>       
>       The same problem also affected the following statements:
>       
>       LOCK TABLES .. WRITE
>       UPDATE .. SET (update and multi-table update)
>       TRUNCATE TABLE ..
>       LOAD DATA ..
>       
>       The solution is to make the above statements wait for a impending
>       global read lock before opening the tables. If there is no
>       impending global read lock, the statement raises a temporary
>       protection against global read locks and progresses smoothly
>       towards completion.
>       
>       Important notice: the patch does not try to address all possible
>       cases, only those which are common and can be fixed unintrusively
>       enough for 5.0.

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.

      
Added a more detailed error message on calling an ambiguous missing function.

mysql-test/r/ps.result:
  Bug #38159: fixed existing tests
mysql-test/r/sp-error.result:
  Bug #38159: test case
mysql-test/t/ps.test:
  Bug #38159: fixed existing tests
mysql-test/t/sp-error.test:
  Bug #38159: test case
sql/item_func.cc:
  Bug #38159: generate more detailed error message
sql/share/errmsg.txt:
  Bug #38159: add a more detailed error message
sql/sql_derived.cc:
  Bug #38159: treat the detailed error message the same way as the
  generic one
sql/sql_lex.cc:
  Bug #38159: 
    - detect if the token is ambiguous and print the appropriate error.
    - backport is_lex_native_function() from 5.1
sql/sql_lex.h:
  Bug #38159: detect if the token is ambiguous and print the appropriate error.
sql/sql_yacc.yy:
  Bug #38159: generate more detailed error message
sql/table.cc:
  Bug #38159: treat the detailed error message the same way as the
  generic one

	comment can't be read back

A change to the lexer in 5.1 caused slash-asterisk-bang-version
sections to be terminated early if there exists a slash-asterisk-
style comment inside it.  Nesting comments is usually illegal,
but we rely on versioned comment blocks in mysqldump, and the
contents of those sections must be allowed to have comments.

The problem was that when encountering open-comment tokens and
consuming -or- passing through the contents, the "in_comment"
state at the end was clobbered with the not-in-a-comment value,
regardless of whether we were in a comment before this or not.  

So, """/*!VER one /* two */ three */""" would lose its in-comment
state between "two" and "three".  Save the echo and in-comment
state, and restore it at the end of the comment if we consume a 
comment.

The problem is that a SELECT .. FOR UPDATE statement might open
a table and later wait for a impeding global read lock without
noticing whether it is holding a table that is being waited upon
the the flush phase of the process that took the global read
lock.

The same problem also affected the following statements:

LOCK TABLES .. WRITE
UPDATE .. SET (update and multi-table update)
TRUNCATE TABLE ..
LOAD DATA ..

The solution is to make the above statements wait for a impending
global read lock before opening the tables. If there is no
impending global read lock, the statement raises a temporary
protection against global read locks and progresses smoothly
towards completion.

Important notice: the patch does not try to address all possible
cases, only those which are common and can be fixed unintrusively
enough for 5.0.

mysql-test/r/lock_multi.result:
  Add test case result for Bug#43230
mysql-test/t/lock_multi.test:
...

An unnecessarily restrictive lock were taken on sub-SELECTs during DELETE.

During parsing, a global structure is reused for sub-SELECTs and the attribute
keeping track of lock options were not reset properly.
This patch introduces a new attribute to keep track on the syntactical lock
option elements found in a sub-SELECT and then sets the lock options accordingly.

Now the sub-SELECTs will try to acquire a READ lock if possible
instead of a WRITE lock as inherited from the outer DELETE statement.


mysql-test/r/lock.result:
  Added test case for bug39843
mysql-test/t/lock.test:
  Added test case for bug39843
sql/sql_lex.cc:
  * Reset member variable lock_option on each new query.
sql/sql_lex.h:
  * Introduced new member variable 'lock_option' which is keeping track
    of the syntactical lock option of a (sub-)select query.
sql/sql_parse.cc:
  * Wrote comments to functions.
sql/sql_yacc.yy:
  * Introduced an attribute to keep track of syntactical lock options
    in sub-selects.
  * Made sure that the default value TL_READ_DEFAULT is at the begining
    of each subselect-rule.

- Remove bothersome warning messages.  This change focuses on the warnings 
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length