A code review comment for Bug#52289.
Encapsulate the deadlock detection functionality into
a visitor class...

Remove a race introduced by omission: 
initialize iterators under a read lock on the object.

sql/mdl.cc:
  Initialize iterators under a read lock on the object.

Encapsulate the deadlock detection functionality into 
a visitor class, and separate it from the wait-for graph
traversal code.

Use "Internal iterator" and "Visitor" patterns to 
achieve the desired separation of responsibilities.

Add comments.

sql/mdl.cc:
  Encapsulate deadlock detection into a class.
sql/mdl.h:
  Adjust for a rename of a class.

and methods.

sql/mdl.cc:
  Add comments.
sql/mdl.h:
  Add a comment.

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

Make open flags part of Open_table_context.
This allows to simplify some code and (in future)
enforce the invariant that we don't, say, request a back 
off on the table when there is MYSQL_OPEN_IGNORE_FLUSH 
flag.



sql/sql_base.cc:
  open_table() flags are part of Open_table_context.
  Remove dead code that would check for OPEN_VIEW_NO_PARSE,
  which is not an open table flag.
sql/sql_base.h:
  Move flags to Open_table_context. Reorder Open_table_context
  members to compact the structure footprint.
sql/sql_insert.cc:
  Update with a new calling signature of open_table().
sql/sql_table.cc:
  Update with a new calling signature of open_table().

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

Move declarations of sql_base.cc classes to sql_base.h
(previously declared in sql_class.h).
Became possible after a header file split.





sql/sql_base.cc:
  Make sql_base.h the first include in sql_base.cc.
sql/sql_base.h:
  Add declarations of Prelocking_strategy and Open_table_context.
sql/sql_class.h:
  Remove declarations of Prelocking_strategy and Open_table_context
  (moved).

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

Remove unused code - TL_WRITE_ALLOW_READ thr_lock.c lock.






include/thr_lock.h:
  Remove TL_WRITE_ALLOW_READ.
mysys/CMakeLists.txt:
  Add thr_lock test to the list of CMake executables to build.
mysys/thr_lock.c:
  Remove TL_WRITE_ALLOW_READ thr_lock.c lock.
  Consequently, simplify lock compatibility rules.
  Remove unused code.
sql/sql_test.cc:
  Remove TL_WRITE_ALLOW_READ lock.

bug #46947 "Embedded SELECT without FOR UPDATE is causing 
a lock".

Fixed comments in tests. Improved comments and performance of
auxiliary scripts.

mysql-test/include/check_concurrent_insert.inc:
  Changed script to use temporary table for backing up data in
  order to make this operation less expensive. Made script more
  a bit generic by allowing to use multi-column tables with it.
  Improved comments.
mysql-test/include/check_no_concurrent_insert.inc:
  Changed script to use temporary table for backing up data in
  order to make this operation less expensive. Made script more
  a bit generic by allowing to use multi-column tables with it.
  Improved comments.
mysql-test/include/check_no_row_lock.inc:
  Improved comments in auxiliary script.
mysql-test/r/innodb_mysql_lock2.result:
  Fixed errors in comments for test.
mysql-test/r/lock_sync.result:
  Fixed typo in comments for test.
mysql-test/t/innodb_mysql_lock2.test:
  Fixed errors in comments for test.
mysql-test/t/lock_sync.test:
  Fixed typo in comments for test.

RENAME is allowed on views (not documented, broken)".

Adjusted test cases in funcs_1 suite after removing support
of ALTER TABLE RENAME for views.

bug #51263 "Deadlock between transactional SELECT and ALTER
TABLE ... REBUILD PARTITION" and has been causing compilation
error when server was built with NDB support.

is allowed on views (not documented, broken)".

Remove support of ALTER TABLE RENAME for views as:
a) this feature was not documented,
c) does not add any compatibility with other databases,
b) its implementation doesn't follow metadata locking
   protocol by accessing .FRM without holding any
   metadata lock,
c) its implementation complicates ALTER TABLE's code
   by introducing  yet another separate branch to it.

After this patch one can rename a view by using the
documented way - RENAME TABLE statement.

mysql-test/r/rename.result:
  Adjusted existing test case for bug #14959 "ALTER TABLE isn't
  able to rename a view" after fixing bug #53976: "ALTER TABLE
  RENAME is allowed on views (not documented, broken)".
mysql-test/r/view.result:
  Adjusted test case after removing support for renaming
  of views through ALTER TABLE ... RENAME.
mysql-test/t/rename.test:
  Adjusted existing test case for bug #14959 "ALTER TABLE isn't
  able to rename a view" after fixing bug #53976: "ALTER TABLE
  RENAME is allowed on views (not documented, broken)".
mysql-test/t/view.test:
  Adjusted test case after removing support for renaming
  of views through ALTER TABLE ... RENAME.
sql/sql_table.cc:
  Removed support for ALTER TABLE ... RENAME for views.
  This feature was not properly documented and its
  implementation was not following metadata locking
  protocol.

objects whose length is stored in a size_t type.

Post-merge fix: Pass the right parameter type to open_and_lock_tables.
Passing FALSE ensures that derived table handling is disabled, truncate
only operates on base tables.

sql/sql_truncate.cc:
  Pass FALSE to disable derived table handling. This was probably
  reminiscent of the use of open_n_lock_single_table, which
  can't be used as in some cases (e.g. merge) more than one
  table will be opened.
sql/sql_truncate.h:
  TABLE_LIST is a struct.

Post-merge fix: Retrieve handler statistics to workaround quirks
of the archive storage engine.

mysql-test/t/archive.test:
  Add test case.
sql/sql_truncate.cc:
  Call info method with has side-effects related to the archive
  storage engine. It will cause rows to become visible, allowing
  a error to be thrown once we attempt to delete the rows.

The problem was that mdl_sync.test was failing sporadically,
due to fact that part of the test didn't take into account
effects of MyISAM's concurrent insert.

This patch solves the problem by making test case robust
against concurrent insert.

SELECT and ALTER TABLE ...  REBUILD PARTITION".

ALTER TABLE on InnoDB table (including partitioned tables)
acquired exclusive locks on rows of table being altered.
In cases when there was concurrent transaction which did
locking reads from this table this sometimes led to a
deadlock which was not detected by MDL subsystem nor by
InnoDB engine (and was reported only after exceeding
innodb_lock_wait_timeout).

This problem stemmed from the fact that ALTER TABLE acquired
TL_WRITE_ALLOW_READ lock on table being altered. This lock
was interpreted as a write lock and thus for table being
altered handler::external_lock() method was called with
F_WRLCK as an argument. As result InnoDB engine treated
ALTER TABLE as an operation which is going to change data
and acquired LOCK_X locks on rows being read from old
version of table.

In case when there was a transaction which already acquired
SR metadata lock on table and some LOCK_S locks on its rows
(e.g. by using it in subquery of DML statement) concurrent
ALTER TABLE was blocked at the moment when it tried to
acquire LOCK_X lock before reading one of these rows.
The transaction's attempt to acquire SW metadata lock on
table being altered led to deadlock, since it had to wait
for ALTER TABLE to release SNW lock. This deadlock was not
detected and got resolved only after timeout expiring
because waiting were happening in two different subsystems.

Similar deadlocks could have occured in other situations.
This patch tries to solve the problem by changing ALTER TABLE
implementation to use TL_READ_NO_INSERT lock instead of
TL_WRITE_ALLOW_READ. After this step handler::external_lock()
is called with F_RDLCK as an argument and InnoDB engine
correctly interprets ALTER TABLE as operation which only
reads data from original version of table. Thanks to this
ALTER TABLE acquires only LOCK_S locks on rows it reads.
This, in its turn, causes inter-subsystem deadlocks to go
away, as all potential lock conflicts and thus deadlocks will
be limited to metadata locking subsystem:

- When ALTER TABLE reads rows from table being altered it
  can't encounter any locks which conflict with LOCK_S row
  locks. There should be no concurrent transactions holding
  LOCK_X row locks. Such a transaction should have been
  acquired SW metadata lock on table first which would have
  conflicted with ALTER's SNW lock.
- Vice versa, when DML which runs concurrently with ALTER
  TABLE tries to lock row it should be requesting only LOCK_S
  lock which is compatible with locks acquired by ALTER,
  as otherwise such DML must own an SW metadata lock on table
  which would be incompatible with ALTER's SNW lock.

mysql-test/r/innodb_mysql_lock2.result:
  Added test for bug #51263 "Deadlock between transactional
  SELECT and ALTER TABLE ... REBUILD PARTITION".
mysql-test/suite/rpl_ndb/r/rpl_ndb_binlog_format_errors.result:
  Since CREATE TRIGGER no longer acquires write lock on table
  it is no longer interpreted as an operation which modifies
  table data and therefore no longer fails if invoked for
  SBR-only engine in ROW mode.
mysql-test/suite/rpl_ndb/t/rpl_ndb_binlog_format_errors.test:
  Since CREATE TRIGGER no longer acquires write lock on table
  it is no longer interpreted as an operation which modifies
  table data and therefore no longer fails if invoked for
  SBR-only engine in ROW mode.
mysql-test/t/innodb_mysql_lock2.test:
  Added test for bug #51263 "Deadlock between transactional
  SELECT and ALTER TABLE ... REBUILD PARTITION".
sql/ha_partition.cc:
  When ALTER TABLE creates a new partition to be filled from
  other partition lock it in F_WRLCK mode instead of using
  mode which was used for locking the whole table (it is
  F_RDLCK now).
sql/lock.cc:
  Replaced conditions which used TL_WRITE_ALLOW_READ
  lock type with equivalent conditions using
  TL_WRITE_ALLOW_WRITE. This should allow to get rid
  of TL_WRITE_ALLOW_READ lock type eventually.
sql/mdl.cc:
  Updated outdated comment to reflect current situation.
sql/sql_base.cc:
  Replaced conditions which used TL_WRITE_ALLOW_READ
  lock type with equivalent conditions using
  TL_WRITE_ALLOW_WRITE. This should allow to get rid
  of TL_WRITE_ALLOW_READ lock type eventually.
sql/sql_table.cc:
  mysql_admin_table():
    Use TL_WRITE_ALLOW_WRITE lock type instead of
    TL_WRITE_ALLOW_READ to determine that we need to acquire
    upgradable metadata lock. This should allow to completely
    get rid of TL_WRITE_ALLOW_READ in long term.
  mysql_recreate_table():
    ALTER TABLE now requires TL_READ_NO_INSERT thr_lock.c lock
    instead of TL_WRITE_ALLOW_READ.
sql/sql_trigger.cc:
  Changed CREATE/DROP TRIGGER implementation to use
  TL_READ_NO_INSERT lock instead of TL_WRITE_ALLOW_READ lock.
  The latter is no longer necessary since:
  a) We now can rely on metadata locks to achieve proper
     isolation between two DDL statements or DDL and DML
     statements.
  b) This statement does not change any data in table so there
     is no need to inform storage engine about it.
sql/sql_yacc.yy:
  Changed implementation of ALTER TABLE (and CREATE/DROP INDEX
  as a consequence) to use TL_READ_NO_INSERT lock instead of
  TL_WRITE_ALLOW_READ lock. This is possible since:
  a) We now can rely on metadata locks to achieve proper
     isolation between two DDL statements or DDL and DML
     statements.
  b) This statement only reads data in table being open.
     We write data only to the new version of table and
     then replace with it old version of table under
     X metadata lock.
  
  Thanks to this change InnoDB will no longer acquire LOCK_X
  locks on rows being read by ALTER TABLE (instead LOCK_S
  locks will be acquired) and thus cause of bug #51263
  "Deadlock between transactional SELECT and ALTER TABLE ...
  REBUILD PARTITION" is removed.
  
  Did the similar change for CREATE TRIGGER (see comments
  for sql_trigger.cc for details).

The problem was that TRUNCATE TABLE didn't take a exclusive
lock on a table if it resorted to truncating via delete of
all rows in the table. Specifically for InnoDB tables, this
could break proper isolation as InnoDB ends up aborting some
granted locks when truncating a table.

The solution is to take a exclusive metadata lock before
TRUNCATE TABLE can proceed. This guarantees that no other
transaction is using the table.

Incompatible change: Truncate via delete no longer fails
if sql_safe_updates is activated (this was a undocumented
side effect).

libmysqld/CMakeLists.txt:
  Add new files to the build list.
libmysqld/Makefile.am:
  Add new files to the build list.
mysql-test/extra/binlog_tests/binlog_truncate.test:
  Add test case for Bug#42643
mysql-test/include/mix1.inc:
  Update test case as TRUNCATE TABLE now grabs a exclusive lock.
  Ensure that TRUNCATE waits for granted locks on the table.
mysql-test/suite/binlog/t/binlog_truncate_innodb.test:
  As with other data modifying statements, TRUNCATE is still not
  possible in a transaction with isolation level READ COMMITTED
  or READ UNCOMMITED. It would be possible to implement so, but
  it is not worth the effort.
mysql-test/suite/binlog/t/binlog_truncate_myisam.test:
  Test under different binlog formats.
mysql-test/suite/binlog/t/disabled.def:
  Re-enable test case.
mysql-test/t/innodb_bug38231.test:
  Truncate no longer works with row-level locks.
mysql-test/t/mdl_sync.test:
  Ensure that a acquired lock is not given up due to a conflict.
mysql-test/t/partition_innodb_semi_consistent.test:
  End transaction as to release metadata locks.
mysql-test/t/truncate.test:
  A metadata lock is now taken before the object is verified.
sql/CMakeLists.txt:
  Add new files to the build list.
sql/Makefile.am:
  Add new files to the build list.
sql/datadict.cc:
  Introduce a new file specific for data dictionary operations.
sql/datadict.h:
  Add header file.
sql/sql_base.cc:
  Rename data dictionary function.
sql/sql_bitmap.h:
  Include dependency.
sql/sql_delete.cc:
  Move away from relying on mysql_delete() to delete all rows of
  a table. Thus, move any bits related to truncate to sql_truncate.cc
sql/sql_delete.h:
  Remove parameter.
sql/sql_parse.cc:
  Add protection against the global read lock -- a intention
  exclusive lock can be acquired in the truncate path.
sql/sql_show.cc:
  Add sync point for testing scenarios where a pending flush
  is ignored.
sql/sql_truncate.cc:
  Acquire a shared metadata lock before accessing table metadata.
  Upgrade the lock to a exclusive one if the table can be re-created.
  Rework binlog rules to better reflect the requirements.
sql/sql_yacc.yy:
  Set appropriate lock types for table to be truncated.
sql/table.h:
  Move to data dictionary header.

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.

FOR UPDATE is causing a lock".
 
This patch tries to address problems which were exposed 
during backporting of original patch to 5.1 tree.
 
- It ensures that we don't change locking behavior of simple
  SELECT statements on InnoDB tables when they are executed
  under LOCK TABLES ... READ and with @@innodb_table_locks=0.
  Also we no longer pass TL_READ_DEFAULT/TL_WRITE_DEFAULT 
  lock types, which are supposed to be parser-only, to 
  handler::start_stmt() method.
- It makes check_/no_concurrent_insert.inc auxiliary scripts 
  more robust against changes in test cases that use them
  and also ensures that they don't unnecessarily change 
  environment of caller.

mysql-test/include/check_concurrent_insert.inc:
  Reset DEBUG_SYNC facility before and after using it in
  auxiliary script. This makes this script more robust against
  changes in test cases calling it. It also ensures that script
  does not unnecessarily change environment of caller.
mysql-test/include/check_no_concurrent_insert.inc:
  Reset DEBUG_SYNC facility before and after using it in
  auxiliary script. This makes this script more robust against
  changes in test cases calling it. It also ensures that script
  does not unnecessarily change environment of caller.
mysql-test/r/innodb-lock.result:
  Added coverage for LOCK TABLES ... READ behavior in
  @@innodb_table_locks = 0 mode. This test also checks
  that an appropriate type of lock is passed to
  handler::start_stmt() method.
mysql-test/t/innodb-lock.test:
  Added coverage for LOCK TABLES ... READ behavior in
  @@innodb_table_locks = 0 mode. This test also checks
  that an appropriate type of lock is passed to
  handler::start_stmt() method.
sql/sql_base.cc:
  Since we no longer set TL_READ as lock type for tables used  
  in simple SELECT right in the parser, in order to preserve  
  behavior for such statements on InnoDB tables when in  
  LOCK TABLES mode with @innodb_table_locks = 0,  
  check_lock_and_start_stmt() had to be changed to convert  
  TL_READ_DEFAULT to an appropriate type of read lock before  
  passing it to handler::start_stmt() method.  
  We do similar thing for TL_WRITE_DEFAULT as this lock type  
  is also supposed to be parser-only type.  
  As consequence read_lock_type_for_table() had to be  
  adjusted to behave properly when it is called from  
  check_lock_and_start_stmt() in prelocked mode.

The problem was that OPTMIZE TABLE was allowed to run on a table
in use by a transaction in a different connection. This caused
repeatable read to break.

This bug was fixed by the introduction of metadata locking, WL#4284.
OPTIMIZE TABLE will now be blocked until the transaction using the
table, has ended.

This patch contains a regression test added to innodb_mysql_lock.test
and no code changes.

That was a pure test issue -- filter implementation in Perl did not work
on some platform (the bug occurred on Windows Server 2008 with
Cygwin Perl 5.10.0).

in a multiquery packet): fix NDB test failures.

removing disabled line for rpl_row_create_table  due to Bug#45576. Anyway, the test is still there because of Bug#51574

pushing to next-mr-bugfixing from working branch

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).

approved):

3161 Vladislav Vaintroub       2010-04-29                 
 Bug#53196 : CMake builds don't support 'make tags' and 
'make ctags' targets.  
   - Added tags and ctags targets


CMakeLists.txt:
  Add tags and ctags targets.
cmake/Makefile.am:
  Add a cmake file to build tags.
cmake/tags.cmake:
  Build tags and ctags.

for ALTER TABLE, LOAD DATA).

ROW_COUNT is now assigned according to the following rules:

  - In my_ok():
    - for DML statements: to the number of affected rows;
    - for DDL statements: to 0.

  - In my_eof(): to -1 to indicate that there was a result set.

    We derive this semantics from the JDBC specification, where int
    java.sql.Statement.getUpdateCount() is defined to (sic) "return the
    current result as an update count; if the result is a ResultSet
    object or there are no more results, -1 is returned".

  - In my_error(): to -1 to be compatible with the MySQL C API and
    MySQL ODBC driver.

  - For SIGNAL statements: to 0 per WL#2110 specification. Zero is used
    since that's the "default" value of ROW_COUNT in the diagnostics area.

sql/protocol.cc:
  Fix a typo.
sql/sql_class.h:
  - Introduce THD::get_row_count_func() / THD::set_row_count_func();
  - Remove the CF_HAS_ROW_COUNT define
sql/sql_parse.cc:
  CF_HAS_ROW_COUNT was eliminated.

type, which some time ago became part of Open_table_context class.
Apparently standalone enum type was erroneously re-introduced
during one of merges.

which was introduced by fix for bug 47459 "Assertion in
Diagnostics_area::set_eof_status on OPTIMIZE TABLE.

 - Update/fix file layouts for each package type, add new types for
   native package formats including deb, rpm and svr4.

 - Build all plugins, including debug versions

 - Update compiler flags to match current release

 - Add missing @VAR@ expansions

 - Install correct mysqclient library symlinks

 - Fix icc/ia64 builds

 - Fix install of libmysqld-debug

 - Don't include mysql_embedded

 - Remove unpackaged manual pages to avoid missing files warnings

 - Don't install mtr's test suite

with other merges from the old distribution-specific spec file.

 - update copyright notices

 - remove __os_install_post override, it was only necessary as a
   hack to build debuginfo packages - now that we no longer make
   them we can revert to the distribution macro which likely has
   other useful bits we might want

 - remove _unpackaged_files_terminate_build override, we want to
   know of any orphaned files

 - include native distribution support

 - no longer build separate debuginfo RPMs, instead just include
   debug/symbols in all binaries, which is more useful for support

 - include support for building commercial RPMs, requires a
   commercial source tree

 - remove cluster RPM support, we don't build them from this
   source tree

 - use CMake for building, and update package lists to match the
   new install layout/files.  Remove any options which were only
   useful for automake builds (e.g. yassl/zlib).

 - other minor cleanups

            via mysqld_safe

Plugin dir was set to a hard-coded path instead of relative the base dir.

This patch fixes this by using a path relative the basedir instead of the
plugin directory indicated by the configuration.