During statement prepare phase the tables were locked as if the
statement is being executed, however this is not necessary.

The solution is to not lock tables on statement prepare phase.
Opening tables is enough to prevent DDL on them, and during statement
prepare we do not access nor modify any data.

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-21904_b-merge

Original patch did not have these leaks, they were introduced later
during manual applying of the patch.

into  weblab.(none):/home/marcsql/TREE/mysql-5.0-21904

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-21904-merge

Before this fix, a IN predicate of the form: "IN (( subselect ))", with two
parenthesis, would be evaluated as a single row subselect: if the subselect
returns more that 1 row, the statement would fail.

The SQL:2003 standard defines a special exception in the specification,
and mandates that this particular form of IN predicate shall be equivalent
to "IN ( subselect )", which involves a table subquery and works with more
than 1 row.

This fix implements "IN (( subselect ))", "IN ((( subselect )))" etc
as per the SQL:2003 requirement.

All the details related to the implementation of this change have been
commented in the code, and the relevant sections of the SQL:2003 spec
are given for reference, so they are not repeated here.

Having access to the spec is a requirement to review in depth this patch.

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-24392

This patch implements the idea of the bug report by making Event_queue
unaware of Event_db_repository by making a higher level class - Events,
which is aware of most of all classes, responsible for passing all data
needed for adding/updating/deleting an event to/from the queue.

Introduces few new classes :
 - Event_worker_thread
 - Event_queue_element_for_exec

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-24392

into  moonlight.home:/home/tomash/src/mysql_ab/mysql-5.1-bug23527

into  mockturtle.local:/home/dlenev/src/mysql-5.1-merge

into  moonlight.home:/home/tomash/src/mysql_ab/mysql-5.0-bug23527

into  moonlight.home:/home/tomash/src/mysql_ab/mysql-5.1-bug23527

           high load

MySQL server could crash if two or more threads would initiate query
cache resize at the moments very close in time.

The problem was introduced with the fix of bug 21051 in 5.0 and 5.1:
simultaneous query cache resizes would wait for the first one in
progress, but then each thread would try to finish the operation,
accessing the data that was already reset (attempt to dereference
'bins' pointer, which may be NULL already).

The solution is to check after synchronization if another thread has
done the reset already (test 'query_cache_size > 0' again).

No test case is provided because the bug is a subject to a race.

  Don't use -Wshadow by default yet

into  mockturtle.local:/home/dlenev/src/mysql-5.1-merge

into  bk-internal.mysql.com:/data0/bk/mysql-5.1-marvel

into  bk-internal.mysql.com:/data0/bk/mysql-5.1-marvel

into  poseidon.mysql.com:/home/tomas/mysql-5.1-new-ndb

into  mockturtle.local:/home/dlenev/src/mysql-5.1-merge

into  mockturtle.local:/home/dlenev/src/mysql-5.0-merge

into  mockturtle.local:/home/dlenev/src/mysql-5.1-merge

into  poseidon.mysql.com:/home/tomas/mysql-5.1-new-ndb

- added extra cluster connect inicator bit for better handeling of delacation of event operations on cluster disconnect
- added extra assert to try to track down valgrind issue

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.1-engines

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.1-engines

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-21029

The build scripts in general, using automake, autoconf, etc, contain several
special commands and work around all related to the way the bison code in the
parser is built, for sql/sql_yacc.yy. These work arounds, accumulated over
time during development, ultimately cause the build scripts to be unstable
and cause build defects by not enforcing dependencies.

This fix simplifies the build process and aligns it with the automake tooling,
which provides native support for bison and *.yy files.

In particular, the following problem have been fixed:
- dependencies with sql_yacc.cc were not honored (Bug 21029), leading to
  corrupted builds,
- the work around introduced by Bug 24557, to cleanup the generated files
  sql_yacc.h and sql_yacc.cc, has been removed,
- the generated makefile, in a source distribution, used to destroy the files
  sql_yacc.h and sql_yacc.cc on a 'make clean' target. This has been fixed:
  these files are now removed by make maintainer-clean.
- The root cause of the problem found with gcc 4.1 (see Bug 24619) has been
  clearly documented, and the "sed" hack has been replaced by a cleaner
  work around, when building the code with bison 1.875.
- Removed the file sql/sql_yacc.yy.bak, added by WL 3031 by accident.
- Removed the unnecessary AM_YFLAG= --debug introduced by WL 3432, since
  the compiling option DBUG_OFF takes precedence when setting YYDEBUG.

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.0-engines

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.0-engines

into  mockturtle.local:/home/dlenev/src/mysql-5.1-merge

the team tree for additional investigation.

into  mockturtle.local:/home/dlenev/src/mysql-5.0-merge

into  mockturtle.local:/home/dlenev/src/mysql-5.1-merge

into  chilla.local:/home/mydev/mysql-5.0-bug24607

into  chilla.local:/home/mydev/mysql-5.1-bug24607