sql/sql_table.cc:
  Fix create.test in --ps-protocol broken by the previous push,
  that added prepared statement validation of CREATE TABLE LIKE:
  move assignment of src_table->required_type to the parser.
sql/sql_yacc.yy:
  Fix create.test in --ps-protocol broken by the previous push,
  that added prepared statement validation of CREATE TABLE LIKE:
  move assignment of src_table->required_type to the parser.

Add metadata validation to ~20 more SQL commands. Make sure that
these commands actually work in ps-protocol, since until now they
were enabled, but not carefully tested.
Fixes the ml003 bug found by Matthias during internal testing of the
patch.


mysql-test/r/ps_ddl.result:
  Update test results (WL#4165)
mysql-test/t/ps_ddl.test:
  Cover with tests metadata validation of 26 SQL statements.
sql/mysql_priv.h:
  Fix the name in the comment.
sql/sp_head.cc:
  Changed the way the observer is removed in case of stored procedures
  to support validation prepare stmt from "call p1(<expr>)": whereas
  tables used in the expression must be validated, substatements
  of p1 must not.
  The previous scheme used to silence the observer only in stored
  functions and triggers.
sql/sql_class.cc:
  Now the observer is silenced in sp_head::execute(). Remove it from
  Sub_statement_state.
sql/sql_class.h:
  Now the observer is silenced in sp_head::execute(). Remove it from
  Sub_statement_state.
sql/sql_parse.cc:
  Add CF_REEXECUTION_FRAGILE to 20 more SQLCOMs that need it.
sql/sql_prepare.cc:
  Add metadata validation to ~20 new SQLCOMs that need it.
  Fix memory leaks with expressions used in SHOW DATABASES and CALL
  (and prepared statements).
  We need to fix all expressions at prepare, since if these expressions
  use subqueries, there are one-time transformations of the parse
  tree that must be done at prepare. 
  List of fixed commands includes: SHOW TABLES, SHOW DATABASES,
  SHOW TRIGGERS, SHOW EVENTS, SHOW OPEN TABLES,SHOW KEYS, SHOW FIELDS, 
  SHOW COLLATIONS, SHOW CHARSETS, SHOW VARIABLES, SHOW TATUS, SHOW TABLE
  STATUS, SHOW PROCEDURE STATUS, SHOW FUNCTION STATUS, CALL.
  Add comment to set_parameters().
sql/table.h:
  Update comments.

WL#4165 Prepared statements: validation 
WL#4166 Prepared statements: automatic re-prepare
Fixes
Bug#27430 Crash in subquery code when in PS and table DDL changed after PREPARE
Bug#27690 Re-execution of prepared statement after table was replaced with a view crashes
Bug#27420 A combination of PS and view operations cause error + assertion on shutdown

The basic idea of the patch is to keep track of table metadata between
prepared statement prepare and execute. If some table used in the statement
has changed, the prepared statement is re-prepared before execution.

See WL#4165 and WL#4166 contents and comments in the code for details
of the implementation.


include/my_global.h:
  Remove 'register' keyword to avoid warnings when swapping large structures
  that don't fit into a register. Any modern compiler is capable of placing
  a variable in a register when that would benefit performance.
mysql-test/r/ps_1general.result:
  Update test results: since now we re-prepare automatically,
  more correct results are produced in prepare-ddl-execute scenario.
mysql-test/r/query_cache_merge.result:
  Ensure that the table definition cache is large enough for
  the test to pass in --ps-protocol
mysql-test/r/trigger.result:
  Update test results to reflect automatic statement reprepare.
mysql-test/t/disabled.def:
  Enable ps_ddl.test, which now passes.
mysql-test/t/ps_1general.test:
  Since now we re-execute prepared statements after DDL successfully,
  change the test to produce repeatable results. Remove expectancy of
  an error in one place where now we automatically reprepare the prepared
  statement.
mysql-test/t/query_cache_merge.test:
  Ensure the table definition cache is large enough for the test to pass
  in --ps-protocol
mysql-test/t/trigger.test:
  Sinc
sql/item.cc:
  Implement Item_param "copy" functionality, used at re-prepare of
  a prepared statement.
  We copy the type of the original parameter, and move the assigned value,
  if any. Sic, the value is "moved", since it can be quite big --
  e.g. in case we deal with a LONG DATA parameter.
  It's essential to move the value from the old parameter since
  at the time of re-prepare the client packet with the necessary information
  may be not available.
sql/item.h:
  Declare a new method used for reprepare.
sql/my_decimal.h:
  Implement "swap()" functionality of class my_decimal to be
  able to easily swap two decimal values.
sql/mysql_priv.h:
  Declare enum_metadata_type.
sql/mysqld.cc:
  Implement a status variable for the number of reprepared statements.
sql/sql_base.cc:
  Implement metadata version validation.
sql/share/errmsg.txt:
  Add two new error messages: ER_NEED_REPREPARE and ER_PS_REBIND.
  The first error (theoretically) never reaches the user.
  It is issued by the metadata validation framework when a metadata version
  has changed between prepare and execute. Later on it's intercepted
  and the statement is automatically re-prepared. Only if the error
  has occurred repeatedly MAX_REPREPARE_ATTEMTS (3) times do we
  return it to the user.
  
  The second error is issued when after re-prepare we discover
  that the metadata we sent over to the client using the binary
  protocol differs drammatically from the new result set metadata 
  that the reprepared statement produces (e.g. number of result
  set columns is different).
sql/sql_class.cc:
  Implement metadata version validation framework.
sql/sql_class.h:
  Declarations for metadata version validation framework.
sql/sql_parse.cc:
  Mark commands for which we must invalidate and reprepare a prepared
  statement when metadata has changed.
sql/sql_prepare.cc:
  Implement WL#4165 and WL#4166 (limited support of metadata validation
  and re-prepare).
sql/table.h:
  Implement metadata validation.
tests/mysql_client_test.c:
  Add a test case for WL#4166

Enable back the disabled test case.


mysql-test/t/disabled.def:
  Enable the test case innodb_mysql.
sql/sql_parse.cc:
  Fix the random failure of innodb_mysql test. The failure is not
  random any more after a patch for Bug 12713 added asserts around
  handler commit.

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

The problem was that symlink.test failed due to debug assertions or
due to errors emitted for wrong statements (in non-debug builds)
if 6.0 version of server was run with --thread-handling=pool-of-threads
option.

The above problems were caused by that on the one hand code mi_create()
which handles case when error is returned relies on my_errno being set
to appropriate non-0 value, but on the other it has not done this
in case when error was emitted due to discovery that share for table
which we are going to create is already present in the list of open
shares. Running server with pool-of-threads option just exposed this
bug since in this scheduler mode my_errno is reset to 0 when connection
(THD) is reattached to the "real" thread.

This fix ensures that code in mi_create() properly sets my_errno in
the case described above.

Since original reason that caused this bug to be exposed in 6.0 tree
might also under very special conditions lead to incorrect behavior
of earlier versions of server (i.e. to errors emitted for wrong
statements) this patch is also being pushed into 5.1 tree.

No test case is present as this code is already covered by a test
case + pushbuild options combination in 6.0.


storage/myisam/mi_create.c:
  Code in mi_create() which handles case when error is returned relies
  on my_errno being set to appropriate non-0 value. Adjusted code which
  emits error when we discover that share for table which we are going
  to create is already present in the list of open shares to do this.

This is a code clean up.
Removed redundant (and unused) TABLE_LIST variable intended as an IN-
parameter for setup_order.


sql/sql_update.cc:
  Removed redundant (and unused) TABLE_LIST variable intended as an IN-
  parameter for setup_order.

into  adventure.(none):/home/thek/Development/cpp/mysql-5.1-runtime


sql/sql_acl.cc:
  Auto merged
mysys/my_thr_init.c:
  Null merge.

into  adventure.(none):/home/thek/Development/cpp/mysql-5.0-runtime


sql/sql_acl.cc:
  Auto merged

into  mysql.com:/Users/davi/mysql/mysql-5.1-runtime


sql/sql_prepare.cc:
  Auto merged

sql/sql_base.cc:
  Remove table definition stage 3 code, stage 3 will be done differently 
  in scope of WL#3726

general_log_file/slow_query_log_file.

The problem was that log file path was rejected if directory
path was empty. The fix is to reject log file path only if it
is entirely empty.


mysql-test/r/log_state.result:
  Update result file.
mysql-test/t/log_state.test:
  A test case for Bug#32748: Inconsistent handling of assignments to
  general_log_file/slow_query_log_file.
sql/set_var.cc:
  Accept file path if dirname is empty.
  Reject file path if it is empty.

We have "set" variables, which can accept empty values
(like sql_mode), and which can not (like log_output). The problem
was that the code does not distinguish them and allow empty
values for every set variable.

The fix is to introduce an attribute of a set variable telling
whether it can accept empty values.


mysql-test/r/variables.result:
  Update result file.
mysql-test/t/variables.test:
  A test case for Bug#34820: log_output can be set to illegal value.
sql/set_var.cc:
  Don't allow empty values if it is prohibitted.
sql/set_var.h:
  Add a flag (m_allow_empty_value) telling if an empty value is
  acceptable for this variable.

into  quad.opbmk:/mnt/raid/alik/MySQL/devel/5.1-rt-merged


mysql-test/r/grant.result:
  Auto merged
mysql-test/t/grant.test:
  Auto merged
sql/sql_acl.cc:
  Auto merged

into  mysql.com:/misc/mysql/mysql-5.1-opt


CMakeLists.txt:
  Auto merged
configure.in:
  Auto merged
include/config-win.h:
  Auto merged
include/my_global.h:
  Auto merged

into  mysql.com:/misc/mysql/mysql-5.0-opt


CMakeLists.txt:
  Auto merged
configure.in:
  Auto merged
include/config-win.h:
  Auto merged
include/my_global.h:
  Auto merged

into  mysql.com:/misc/mysql/mysql-5.1-opt


CMakeLists.txt:
  Auto merged
configure.in:
  Auto merged
include/config-win.h:
  Auto merged
include/my_global.h:
  Auto merged
sql/sql_acl.cc:
  Auto merged
sql/sql_db.cc:
  Auto merged
storage/innobase/handler/ha_innodb.cc:
  Auto merged

into  host.loc:/home/uchum/work/5.1-opt


configure.in:
  Auto merged
sql/item.cc:
  Auto merged

into  host.loc:/home/uchum/work/5.0-opt


configure.in:
  Auto merged
sql/item.cc:
  Auto merged

into  trift2.:/MySQL/M51/push-5.1

into  trift2.:/MySQL/M51/push-5.1

into  trift2.:/MySQL/M50/push-5.0

into  trift2.:/MySQL/M51/push-5.1

into  host.loc:/home/uchum/work/5.1-opt


sql/sql_delete.cc:
  Auto merged
sql/sql_prepare.cc:
  Auto merged
sql/sql_update.cc:
  Auto merged
configure.in:
  SCCS merged

into  pippilotta.erinye.com:/shared/home/df/mysql/build/mysql-5.1-build


BitKeeper/deleted/.del-configure.js:
  Auto merged

into  host.loc:/home/uchum/work/5.0-opt


configure.in:
  Merge with 4.1-opt.

into  host.loc:/home/uchum/work/5.1-opt


client/mysqltest.c:
  Auto merged
mysql-test/r/information_schema.result:
  Auto merged
mysql-test/t/information_schema.test:
  Auto merged
sql/item.cc:
  Auto merged
sql/log.cc:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/sql_acl.cc:
  Auto merged
sql/sql_base.cc:
  Auto merged
sql/sql_delete.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_prepare.cc:
  Auto merged
sql/sql_show.cc:
  Auto merged
sql/sql_table.cc:
  Auto merged
sql/sql_update.cc:
  Auto merged

into  trift2.:/MySQL/M51/push-5.1


configure.in:
  Auto merged

into  host.loc:/home/uchum/work/5.0-opt


sql/sql_delete.cc:
  Auto merged
sql/sql_prepare.cc:
  Auto merged
sql/sql_update.cc:
  Auto merged

into  trift2.:/MySQL/M51/push-5.1


configure.in:
  Auto merged
mysql-test/r/federated.result:
  Auto merged
mysql-test/t/federated.test:
  Auto merged

into  trift2.:/MySQL/M50/push-5.0


configure.in:
  Auto merged

into  quad.opbmk:/mnt/raid/alik/MySQL/devel/5.1-rt-merged


mysql-test/t/disabled.def:
  Auto merged

into  rhel5-ia64-a.mysql.com:/data0/tsmith/build/51

into  rhel5-ia64-a.mysql.com:/data0/tsmith/build/50

into  rhel5-ia64-a.mysql.com:/data0/tsmith/build/51