The problem was that issuing XA END when the XA transaction was
already ended, caused an assertion. This assertion tests that 
the server does not try to send OK to the client if there has
already been an error reported. The bug was only noticeable on
debug versions of the server.

The reason for the problem was that the trans_xa_end() function
reported success if the transaction was at XA_IDLE state at the
end regardless of any errors occured during processing of
trans_xa_end(). So if the transaction state was XA_IDLE already,
reported errors would be ignored.

This patch fixes the problem by having trans_xa_end() take into
consideration any reported errors. The patch also fixes a similar
bug with XA PREPARE.

Test case added to xa.test.

table causes assert failure".

Attempting to use FLUSH TABLE table_list WITH READ LOCK
statement for a MERGE table led to an assertion failure if
one of its children was not present in the list of tables
to be flushed. The problem was not visible in non-debug builds.

The assertion failure was caused by the fact that in such
situations FLUSH TABLES table_list WITH READ LOCK implementation
tried to use (e.g. lock) such child tables without acquiring
metadata lock on them. This happened because when opening tables
we assumed metadata locks on all tables were already acquired
earlier during statement execution and a such assumption was
false for MERGE children.

This patch fixes the problem by ensuring at open_tables() time
that we try to acquire metadata locks on all tables to be opened. 
For normal tables such requests are satisfied instantly since
locks are already acquired for them. For MERGE children metadata
locks are acquired in normal fashion.

Note that FLUSH TABLES merge_table WITH READ LOCK will lock for
read both the MERGE table and its children but will flush only 
the MERGE table. To flush children one has to mention them in table
list explicitly. This is expected behavior and it is consistent with
usage patterns for this statement (e.g. in mysqlhotcopy script).

mysql-test/r/flush.result:
  Added test case for bug #55273 "FLUSH TABLE tm WITH READ LOCK
  for Merge table causes assert failure".
mysql-test/t/flush.test:
  Added test case for bug #55273 "FLUSH TABLE tm WITH READ LOCK
  for Merge table causes assert failure".
sql/sql_base.cc:
  Changed lock_table_names() to support newly introduced
  MYSQL_OPEN_SKIP_SCOPED_MDL_LOCK flag.
sql/sql_base.h:
  Introduced MYSQL_OPEN_SKIP_SCOPED_MDL_LOCK flag for
  open_tables() and lock_table_names() which allows to skip
  acquiring of global and schema-scope locks when SNW, SNRW or
  X metadata locks are acquired.
sql/sql_reload.cc:
  Changed "FLUSH TABLES table_list WITH READ LOCK" code not to
  cause assert about missing metadata locks when MERGE table is
  flushed without one of its underlying tables.
  To achieve this we no longer call open_and_lock_tables() with
  MYSQL_OPEN_HAS_MDL_LOCK flag so this function automatically
  acquires metadata locks on MERGE children if such lock has
  not been already acquired at earlier stage. Instead we call
  this function with MYSQL_OPEN_SKIP_SCOPED_MDL_LOCK flag to
  suppress acquiring of global IX lock in order to keep FLUSH
  TABLES  table_list WITH READ LOCK compatible with FLUSH TABLE
  WITH READ LOCK.
  Also changed implementation to use lock_table_names() function
  for pre-acquiring of metadata locks instead of custom code.
  To implement this change moved setting of open_type member for
  table list elements to parser.
sql/sql_yacc.yy:
  Now we set acceptable type of table for FLUSH TABLES table_list
  WITH READ LOCK at parsing time instead of execution time.

mysys/my_sync.c: In function 'my_sync_dir':
mysys/my_sync.c:103:29: error: unused parameter 'dir_name'
mysys/my_sync.c:103:43: error: unused parameter 'my_flags'
mysys/my_sync.c: In function 'my_sync_dir_by_file':
mysys/my_sync.c:144:37: error: unused parameter 'file_name'
mysys/my_sync.c:144:52: error: unused parameter 'my_flags'

mysys/my_gethwaddr.c: In function 'my_gethwaddr':
mysys/my_gethwaddr.c:67:11: error: pointer targets in assignment differ in signedness

Add a virtual destructor. Class has virtual functions.

With recent changes in the performance schema default sizing parameters,
the memory used by a mysqld binary increased accordingly.

This negatively affects the MTR test suite,
because running several tests in parallel now consumes more ressources.

The fix is to leave the default production values unchanged,
and to configure the MTR environment to limit memory
used when running tests in the test suite, which is ok
because only a few objects are typically used within a test script.

This fix:
- changed the default configuration in MTR to use less memory
- adjusted the performance schema tests accordingly

Note that 1,000 mutex instances was too short and caused test failures
in the past in team trees, so the default used is now 10,000 in MTR.

The amount of memory used by the performance schema itself
can be observed with the statement SHOW ENGINE PERFORMANCE_SCHEMA STATUS

ALTER TABLE on a MERGE table could cause a deadlock with two
other connections if we reached a situation where:

1) A connection doing ALTER TABLE can't upgrade to MDL_EXCLUSIVE on the
parent table, but holds TL_READ_NO_INSERT on the child tables.
2) A connection doing DELETE on a child table can't get TL_WRITE on it
since ALTER TABLE holds TL_READ_NO_INSERT.
3) A connection doing SELECT on the parent table can't get TL_READ on 
the child tables since TL_WRITE is ahead in the lock queue, but holds
MDL_SHARED_READ on the parent table preventing ALTER TABLE from upgrading.

For regular tables, this deadlock is avoided by having ALTER TABLE
take a MDL_SHARED_NO_WRITE metadata lock on the table. This prevents
DELETE from acquiring MDL_SHARED_WRITE on the table before ALTER TABLE
tries to upgrade to MDL_EXCLUSIVE. In the example above, SELECT would
therefore not be blocked by the pending DELETE as DELETE would not be
able to enter TL_WRITE in the table lock queue.

This patch fixes the problem for merge tables by using the same metadata
lock type for child tables as for the parent table. The child tables will
in this case therefore be locked with MDL_SHARED_NO_WRITE, preventing
DELETE from acquiring a metadata lock and enter into the table lock queue.

Change in behavior: By taking the same metadata lock for child tables
as for the parent table, LOCK TABLE on the parent table will now also
implicitly lock the child tables. Since LOCK TABLE on the parent table
now takes more than one metadata lock, it is possible for LOCK TABLE
... WRITE on the parent table or child tables to give ER_LOCK_DEADLOCK
error.

Test case added to mdl_sync.test.
Merge.test/.result has been updated to reflect the change to LOCK TABLE.

The Item_func_str_to_date class wasn't providing correct integer DATETIME
representation as expected. This led to wrong comparison result and didn't
allowed the STR_TO_DATE function to be used with indexes.
Also, STR_TO_DATE function was inconsisted on throwing warnings/errors.
Fixed now.

val_int and result_as_longlong methods were added to the Item_func_str_to_date
class. 

mysql-test/r/func_time.result:
  Test case result adjusted after fixing bug#56271.
mysql-test/r/parser.result:
  Test case result adjusted after fixing bug#56271.
mysql-test/r/select.result:
  A test case result adjusted after fixing bug#56271.
mysql-test/r/strict.result:
  Test case result adjusted after fixing bug#56271.
mysql-test/r/type_datetime.result:
  Added a test case for the bug#56271.
mysql-test/t/strict.test:
  Test case adjusted after fixing bug#56271.
mysql-test/t/type_datetime.test:
  Added a test case for the bug#56271.
sql/item_timefunc.cc:
  Bug#56271: Wrong comparison result with STR_TO_DATE function
  val_int and result_as_longlong methods were added to the Item_func_str_to_date
  class. 
  Item_func_str_to_date::get_date now throws the ER_WRONG_VALUE_FOR_TYPE warning
  on incorrect value.
sql/item_timefunc.h:
  Bug#56271: Wrong comparison result with STR_TO_DATE function
  val_int and result_as_longlong methods were added to the Item_func_str_to_date
  class.

On Solaris with version 3.4.6, the ha_example.so shared library is built
with DTrace and the server is built without DTrace support. This occurs
because dtrace.cmake disables DTrace support for 3.4.6, but still set
HAVE_DTRACE, which causes probes_mysql.h to include probes_mysql_dtrace.h
instead of probes_mysql_nodtrace.h.

This patch fixes this by not setting HAVE_DTRACE on Solaris for GCC 3.4.6.

 create data dir correctly in initial_database target on Windows
 handle case where INSTALL_MYSQLTESTDIR is empty (e.g someone does not want
 to install tests)

          thread-specific variables weren't set when we load error message files.

per-file comments:
  libmysqld/lib_sql.cc
Bug#53251      mysql_library_init fails on second execution with embedded library
      we need to call my_thread_init() once more. Normally it's called at the my_init()
      stage but that doesn't happen on the second my_init() call.

  sql/derror.cc
Bug#53251      mysql_library_init fails on second execution with embedded library
     use default errors for the embedded server.

  sql/mysqld.cc
Bug#53251      mysql_library_init fails on second execution with embedded library
        unregister server errors in clean_up(). Without it the error list contains
        that on the second mysql_server_init() which is not good.

  sql/set_var.cc
Bug#53251      mysql_library_init fails on second execution with embedded library
        sys_var::cleanup() call instead of the destructor

  sql/set_var.h
Bug#53251      mysql_library_init fails on second execution with embedded library
        sys_var::cleanup() introduced instead of the destructor
        
  sql/sys_vars.h
Bug#53251      mysql_library_init fails on second execution with embedded library
        Sys_var_charptr::cleanup() implemented

Merge cleanup, fixed a build warning:

my_getopt.c:156: warning: 'opt_found' may be used uninitialized in this function

        When in embedded-serve mode, mysqltest tried to run '--send' commands in the separate thread.
        That upsets some engines (InnoDB particularly) as the transaction has to be executed in the same
        thread completely. So i implemented some different approach. So we create one separate thread for
        each connection and execute all the queries of this connection inside it. Looks even simpler than it was
        for me.

per-file comments:
  client/mysqltest.cc
Bug#54861      Additional connections not handled properly in mtr --embedded
        Now the connection has one running connection_thread() attached. And sends all the
        query and read-result requests to it.

       made libmysqld/Makefile.am to have same licence as libmysqld/CMakeLists.txt

per-file comments:
  libmysqld/Makefile.am
Bug#54906      Inconsistent license of libmysqld
        Added GPL license header instead of Library GPL.

Problem:
- ORDER BY for utf8mb4_bin, utf16_bin and utf32_bin returned
  results in a wrong order, because old functions
  (supporting only BMP range) were used to handle these collations.
- Additionally, utf16_bin did not sort supplementary characters
  between U+D700 and U+E000, as WL#1213 specification specified.

include/m_ctype.h:
  Adding prototypes.
mysql-test/include/ctype_filesort2.inc:
  Adding a new shared test file.
mysql-test/t/ctype_utf8mb4.test:
  Adding tests.
strings/ctype-ucs2.c:
  - Fixing my_strncoll[sp]_utf16_bin to compare
    binary representation instead of code points,
    to make columns with indexes sort correct.
  - Fixing my_collation_handler_utf32_bin and
    my_collation_handler_utf16_bin to use new
    functions.
strings/ctype-utf8.c:
  - Adding my_strnxfrm[len]_unicode_fill_bin()
    to handle utf8mb4_bin, utf16_bin and utf32_bin,
    using 3 bytes per weight.
    This function also performs special reordering in case of utf16_bin.
  - Fixing my_collation_utf8mb4_bin handler to use the
    new function.

to allow temp table operations) -- prerequisite patch #3.

Rename open_temporary_table() to open_table_uncached().
open_temporary_table() will be introduced in following patches
to open temporary tables for a statement.

check_merge_table_access() used to do two things:
  - set proper database for every merge table child;
  - check SELECT | UPDATE | DELETE for merge table children.

Setting database is not needed anymore, since it's done
on the parsing stage.

Thus, check_merge_table_access() can be removed;
needed privileges can be checked using check_table_access().

This allows to avoid mixing it up with pointer to TABLE object
which will be introduced to this function in one of upcoming
patches.

It was added by mistake during backport from 6.0.

to allow temp table operations) -- prerequisite patch #2.

Introduce a new form of find_temporary_table() function:
find_temporary_table() by a table key. It will be used
in further patches.

Replace find_temporary_table(table_list->db, table_list->name)
by more appropiate find_temporary_table(table_list) across
the codebase.

from 5.1.50 to 5.5.6".

Debug builds of the server aborted due to an assertion
failure when DROP DATABASE statement was run on an
installation which had outdated or corrupt mysql.proc table.
Particularly this affected the mysql_upgrade tool which is
run as part of 5.1 to 5.5 upgrade.

The problem was that sp_drop_db_routines(), which was invoked
during dropping of the database, could have returned without
closing and unlocking mysql.proc table in cases when this
table was not up-to-date with the current server. As a result
further attempt to open and lock the mysql.event table, which
was necessary to complete dropping of the database, ended up
with an assert.

This patch solves this problem by ensuring that
sp_drop_db_routines() always closes mysql.proc table and
releases metadata locks on it. This is achieved by changing
open_proc_table_for_update() function to close tables and
release metadata locks acquired by it in case of failure.
This step also makes behavior of the latter function
consistent with behavior of open_proc_table_for_read()/
open_and_lock_tables().


Test case for this bug was added to sp-destruct.test.

            "Access compatibility" syntax

The "wild" "DELETE FROM table_name.* ... USING ..." syntax
for multi-table DELETE statements is documented but it was
lost in the fix for the bug 30234.

The table_ident_opt_wild parser rule has been added
to restore the lost syntax.


mysql-test/r/delete.result:
  Test case for bug #53034.
mysql-test/t/delete.test:
  Test case for bug #53034.
sql/sql_yacc.yy:
  Bug #53034: Multiple-table DELETE statements not accepting
              "Access compatibility" syntax
  
  The table_ident_opt_wild parser rule has been added
  to restore the lost syntax.
  Note: simple extending of table_ident with opt_wild in
  the table_alias_ref rule is not acceptable, because
  a) it adds one conflict more and b) this conflict resolves
  in the inappropriate way.

 - Remove include of ha_ndbcluster_tables.h from mysqldump.c

so test case has to be updated.