Test mysql_plugin failed if version string ended in -mN

FOR CERTAIN QUERIES TO INFORMATION_SCHEMA".

The problem was that metadata locking subsystem introduced
too much overhead for queries to I_S which were processed by
opening only .FRM or .TRG files and had to scanned a lot of
tables (e.g. SELECT COUNT(*) FROM I_S.TRIGGERS was affected). 
The same effect was not observed for similar queries which 
performed full-blown table open in order to fill I_S table.

The problem stemmed from the fact that in case when I_S 
implementation opened only .FRM or .TRG file for each table 
processed it didn't release metadata lock it has acquired on 
the table after finishing its processing. As result, list
of acquired metadata locks were growing until the end of 
statement. Since acquisition of each new lock required 
search in the list of already acquired locks performance
degraded.

The same effect is not observed when I_S implementation
performs full-blown table open for each table being
processed, as in the latter cases metadata lock on the
table is released right after table processing.

This fix addressed the problem by ensuring that I_S 
implementation releases metadata lock after processing
the table in both cases of full-blown table open and in 
case when only .FRM or .TRG file is read.

mysql-test/r/information_schema.result:
  Added coverage for bug #12828477 - "MDL SUBSYSTEM CREATES BIG
  OVERHEAD FOR CERTAIN QUERIES TO INFORMATION_SCHEMA".
mysql-test/t/information_schema.test:
  Added coverage for bug #12828477 - "MDL SUBSYSTEM CREATES BIG
  OVERHEAD FOR CERTAIN QUERIES TO INFORMATION_SCHEMA".
sql/sql_show.cc:
  Changed fill_schema_table_from_frm() to release metadata lock
  it has acquired after processing the .FRM or .TRG file for
  table. 
  Without this step metadata locks acquired for each table 
  processed will be accumulated. In situation when a lot of 
  tables are processed by I_S query this will result in
  transaction with too many metadata locks. As result
  performance of acquisition of new lock will degrade.

(avert regression)

Merge with main prior to pushing to mysql-5.5.

Bug#12664445 - SYS_VARS.ALL_VARS: WRONG RESULTS RECORDED IN RESULT FILE - TEST CASES MISSING! 
      
The bug had missing test cases for three system variables. 
Test cases have been added for these variables:
'INNODB_FILE_FORMAT_MAX' 
'INNODB_ROLLBACK_SEGMENTS'
'INNODB_STATS_METHOD'
      
The 'sys_vars.all_vars' result file now looks like this:
      
select variable_name as `There should be *no* variables listed below:` from t2
left join t1 on variable_name=test_name where test_name is null;
There should be *no* variables listed below:
      
INNODB_LARGE_PREFIX
INNODB_LARGE_PREFIX
      
The variable 'INNODB_LARGE_PREFIX' is a newly added variable for MySQL 5.6.3 and the test will be added later by the developer.

row_sel_field_store_in_mysql_format(): Do not pad the unused part of
the buffer reserved for a True VARCHAR column (introduced in 5.0.3).
Add Valgrind instrumentation ensuring that the unused part will be
flagged uninitialized.

row_sel_copy_cached_field_for_mysql(): New function: Copy a field
that is in the MySQL row format, not copying the unused tail of
VARCHAR columns.

row_sel_pop_cached_row_for_mysql(): Invoke
row_sel_copy_cached_field_for_mysql() for copying fields.
When the row is long, copy it field-by-field.

rb:715 approved by Inaam Rana

This patch corrects an error in the test to ensure the proper path
is used for the --mysqld option.

This patch corrects a problem found in PB. Some platforms have very
different locations for the mysql installation. The client was not
able to find either my_print_defaults or mysqld predictably.

The patch adds two new command options --mysqld and --my-print-defaults
which can be used to provide the location of mysqld and
my_print_defaults by providing the paths.

The patch also changes the concatenation of the soname extension to
fix a problem found on some Ubuntu systems.

The patch contains changes to the test to ensure it will run on all
platforms. A trap is set in the test to skip testing if the location
of mysqld, my_print_defaults, or the daemon_example.ini files cannot
be determined.

for compressed InnoDB tables

ha_innodb::info_low(): For calculating data_length or index_length,
use the compressed page size for compressed tables instead of UNIV_PAGE_SIZE.

rb:714 approved by Sunny Bains

BUG #11754979 - 46675: ON DUPLICATE KEY UPDATE AND UPDATECOUNT() POSSIBLY WRONG 

The mysql_affected_rows() client call returns 3 instead of 2 on
INSERT ... ON DUPLICATE KEY UPDATE query with a duplicated key value.

The fix for the old bug #29692 was incomplete: unnecessary double
increment of "touched" rows still happened.

This bugfix removes:
1) unneeded increment of "touched" rows and
2) useless double resetting of auto-increment value.


sql/sql_insert.cc:
  write_record() function:
  Unneeded increment of "touched" rows and useless double resetting
  of auto-increment value has been removed.
tests/mysql_client_test.c:
  New test case.

There is an optimization of DISTINCT in JOIN::optimize()
which depends on THD::used_tables value. Each SELECT statement
inside SP resets used_tables value(see mysql_select()) and it
leads to wrong result. The fix is to replace THD::used_tables
with LEX::used_tables.


mysql-test/r/sp.result:
  test case
mysql-test/t/sp.test:
  test case
sql/sql_base.cc:
  THD::used_tables is replaced with LEX::used_tables
sql/sql_class.cc:
  THD::used_tables is replaced with LEX::used_tables
sql/sql_class.h:
  THD::used_tables is replaced with LEX::used_tables
sql/sql_insert.cc:
  THD::used_tables is replaced with LEX::used_tables
sql/sql_lex.cc:
  THD::used_tables is replaced with LEX::used_tables
sql/sql_lex.h:
  THD::used_tables is replaced with LEX::used_tables
sql/sql_prepare.cc:
  THD::used_tables is replaced with LEX::used_tables
sql/sql_select.cc:
  THD::used_tables is replaced with LEX::used_tables

  Add extra patterns to look for @<platform>

The problem is that TIME_FUZZY_DATE is explicitly used for get_arg0_date()
function in Item_date_typecast::get_date method. The fix is to use real
fuzzy_date value.


mysql-test/r/func_time.result:
  test case
mysql-test/t/func_time.test:
  test case
sql/item_timefunc.cc:
  use real fuzzy_date value

This patch corrects a problem found in pushbuild with the stat()
method on some platforms. The code was changed to use my_stat()
instead.

Also adds mysql_plugin to the mysql.spec.sh file for packaging.

In 5.5, REFRESH SLAVE is used as an alias for RESET SLAVE and
was removed in 5.6. Reseting a slave through REFRESH SLAVE was
causing errors in the valgrind platform since reset_slave_info
was undefined.

To fix the problem, we have set reset_slave_info while calling
REFRESH SLAVE.

SHOW ALL PROBLEMS FOR MERGE TABLE COMPLIANCE IN 5.1".

The problem was that CHECK/REPAIR TABLE for a MERGE table which
had several children missing or in wrong engine reported only
issue with the first such table in its result-set. While in 5.0
this statement returned the whole list of problematic tables.

Ability to report problems for all children was lost during
significant refactorings of MERGE code which were done as part
of work on 5.1 and 5.5 releases.

This patch restores status quo ante refactorings by changing
code in such a way that:
1) Failure to open child table due to its absence during CHECK/
   REPAIR TABLE for a MERGE table is not reported immediately
   when its absence is discovered in open_tables(). Instead
   handling/error reporting in such a situation is postponed
   until the moment when children are attached.
2) Code performing attaching of children no longer stops when
   it encounters first problem with one of the children during
   CHECK/REPAIR TABLE. Instead it continues iteration through
   the child list until all problems caused by child absence/
   wrong engine are reported.

Note that even after this change problem with mismatch of
child/parent definition won't be reported if there is also
another child missing, but this is how it was in 5.0 as well.

mysql-test/r/merge.result:
  Added test case for bug #11754210 - "45777: CHECK TABLE DOESN'T
  SHOW ALL PROBLEMS FOR MERGE TABLE COMPLIANCE IN 5.1".
  Adjusted results of existing tests to the fact that CHECK/REPAIR
  TABLE statements now try to report problems about missing table/
  wrong engine for all underlying tables, and to the fact that
  mismatch of parent/child definitions is always reported as an
  error and not a warning.
mysql-test/t/merge.test:
  Added test case for bug #11754210 - "45777: CHECK TABLE DOESN'T
  SHOW ALL PROBLEMS FOR MERGE TABLE COMPLIANCE IN 5.1".
sql/sql_base.cc:
  Changed code responsible for opening tables to ignore the fact
  that underlying tables of a MERGE table are missing, if this
  table is opened for CHECK/REPAIR TABLE.
  The absence of underlying tables in this case is now detected and
  appropriate error is reported at the point when child tables are
  attached. At this point we can produce full list of problematic
  child tables/errors to be returned as part of CHECK/REPAIR TABLE
  result-set.
storage/myisammrg/ha_myisammrg.cc:
  Changed myisammrg_attach_children_callback() to handle new
  situation, when during CHECK/REPAIR TABLE we do not report 
  error about missing child immediately when this fact is 
  discovered during open_tables() but postpone error-reporting
  till the time when children are attached. 
  Also this callback is now responsible for pushing an error
  mentioning problematic child table to the list of errors to 
  be reported by CHECK/REPAIR TABLE statements.
  Finally, since now myrg_attach_children() no longer relies on
  return value from callback to determine the end of the children
  list, callback no longer needs to set my_errno value and can
  be simplified.
  
  Changed myrg_print_wrong_table() to always report a problem
  with child table as an error and not as a warning. This makes
  reporting for different types of issues with child tables
  more consistent and compatible with 5.0 behavior.
storage/myisammrg/myrg_open.c:
  Changed code in myrg_attach_children() not to abort on the
  first problem with a child table when attaching children to
  parent MERGE table during CHECK/REPAIR TABLE statement 
  execution. This allows CHECK/REPAIR TABLE to report problems 
  about absence/wrong engine for all underlying tables as
  part of their result-set.