Background: Backporting fix for BUG 11752963 to Mysql5.1 branch.
Problem: Fix of bug 11752963 was only available for trunk and 5.5 branch.
Partial fix has been pushed to 5.1 branch as well. 
Fix: backporting the fixes of bug 11752963 to 5.1 branch. 
1. Made all major changes to make 5.1 branch in line with 5.5 and the trunk.
2. skipped the partial patch that was already applied to the 5.1 branch. 

Suppress the known warnings generated by filesort().

The real fix belongs to worklog 1509:
Pack values of non-sorted fields in the sort buffer
(which is basically the same issue, but in an optimization context:
 We are writing the entire sort buffer to disk, 
 including un-used space for varchar columns.)

The fix in revision id marko.makela@oracle.com-20110815091143-h3zbvm0pv8ni3qql
introduced a false UNIV_SYNC_DEBUG alarm. Relax the assertion.

but some notation improvement is applicable.

On Fedora, certain accesses to "/var/lib/mysql/HOSTNAME.err" were blocked
by SELinux policy, this made the server start fail with the message
    Manager of pid-file quit without updating file
Calling "/sbin/restorecon -R /var/lib/mysql" fixes this.

                      CRASHES SERVER

Flushing of MERGE table or one of its child tables, which was
locked by flushing thread using LOCK TABLES, might have caused
crashes or assertion failures if the thread failed to reopen
child or parent table.
Particularly, this might have happened when another connection
killed this FLUSH TABLE statement/connection.
Also this problem might have occurred when we failed to reopen
MERGE table or one of its children when executing DDL statement
under LOCK TABLES.

The problem was caused by the fact that reopen_tables() might
have failed to reopen child table but still tried to reopen,
reattach children for and re-lock its parent. Vice versa it
might have failed to reopen parent but kept references from
children to parent around. Since reopen_tables() closes table
it has failed to reopen and therefore frees all associated
memory such dangling references led to crashes when followed.

This patch solves this problem by ensuring that we always close
parent table and all its children if we fail to reopen this
table or one of its children. Same happens if we fail to reattach
children to parent.

Affects 5.1 only.

"!is_index_name" instead of "is_index_name", so the table name in the
error message would not be formated as index name.

sys_vars test suite.

Also addressed issues in bug #11745133, where we could mark a table
corrupted instead of crashing the server when found a corrupted buffer/page
if the table created with innodb_file_per_table on.

conflict on "configure.in" which is gone from 5.5.
No change.

discarded in buf_page_create()

This bug turned out to be a false alarm, a bug in the UNIV_SYNC_DEBUG
diagnostic code. Because of this, the patch was not backported to the
built-in InnoDB in MySQL 5.1. Furthermore, there is no test case for
InnoDB Plugin in MySQL 5.1, because the delete buffering in MySQL 5.5
makes triggering the failure much easier.

When a freed page for which there exist orphaned buffered changes is
allocated and reused for something else, buf_page_create() will discard
the buffered changes by invoking ibuf_merge_or_delete_for_page().
This would violate the InnoDB latching order.

Tweak the latching order as follows. Move SYNC_IBUF_MUTEX below
SYNC_FSP_PAGE, where it logically belongs, and assign new latching
levels for the ibuf->index->lock and the insert buffer B-tree pages:

#define SYNC_IBUF_MUTEX		370	/* ibuf_mutex */
#define SYNC_IBUF_INDEX_TREE	360
#define SYNC_IBUF_TREE_NODE_NEW	359
#define SYNC_IBUF_TREE_NODE	358

btr_block_get(), btr_page_get(): In UNIV_SYNC_DEBUG, add the parameter
"index" for determining the appropriate latching order
(SYNC_IBUF_TREE_NODE or SYNC_TREE_NODE).

btr_page_alloc_for_ibuf(), btr_create(): Use SYNC_IBUF_TREE_NODE_NEW
instead of SYNC_TREE_NODE_NEW for insert buffer pages.

btr_cur_search_to_nth_level(), btr_pcur_restore_position_func(): Use
SYNC_IBUF_TREE_NODE instead of SYNC_TREE_NODE for insert buffer pages.

btr_search_guess_on_hash(): Assert that the index is not an insert buffer tree.

dict_index_add_to_cache(): Use SYNC_IBUF_INDEX_TREE for the insert
buffer tree (ibuf->index->lock).

ibuf0ibuf.c: Use SYNC_IBUF_TREE_NODE or SYNC_IBUF_TREE_NODE_NEW for
all B-tree pages.

ibuf_merge_or_delete_for_page(): Assert that the user page is
BUF_IO_READ fixed. Only in this way it is OK to latch it as
SYNC_IBUF_TREE_NODE instead of the proper SYNC_TREE_NODE (which would
violate the changed latching order).

sync_thread_add_level(): Remove the special tweak for
SYNC_IBUF_MUTEX. Add rules for the added latching levels.

rb:591 approved by Jimmy Yang

Pushed Calvin's patch.

  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.

(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