to the autotools option mysql-maintainer-mode. This option is
intended to set a few flags that should be activated by anyone
doing MySQL development, regardless of the build type. Also, the
flags are only set by the very end of the platform checks as
to not disturb fragile checks.

of autoconf and is not strictly needed for now.

Although the C standard mandates that sprintf return the number
of bytes written, some very ancient systems (i.e. SunOS 4)
returned a pointer to the buffer instead. Since these systems
are not supported anymore and are hopefully long dead by now,
simply remove the portability wrapper that dealt with this
discrepancy. The autoconf check was causing trouble with GCC.

Introduce a MySQL maintainer/developer mode that enables
a set of warning options for the C/C++ compiler. This mode
is intended to help improve the overall quality of the code.

The warning options are:

C_WARNINGS="-Wall -Wextra -Wunused -Wwrite-strings -Werror"
CXX_WARNINGS="$C_WARNINGS -Wno-unused-parameter"

Since -Wall is essentially a moving target, autoconf checks
are not run with warning options enabled, in particualr -Werror.
This decision might be revisited in the future. The patch also
fixes a mistake in the makefiles, where automake CXXFLAGS would
be set to CFLAGS.

config/ac-macros/maintainer.m4:
  Add a set of default compiler flags used when in maintainer mode.
configure.in:
  Hook into the maintainer mode. Disabled by default.

In bug-28430 HA_PRIMARY_KEY_REQUIRED_FOR_POSITION
was disabled in the partitioning engine in the first patch,
That bug was later fixed a second time, but that flag
was not removed.

No need to disable this flag, as it leads to bad
choise in row replication.

sql/ha_partition.h:
  Not disabling HA_PRIMARY_KEY_REQUIRED_FOR_POSITION flag.
  Updated comment (has nothing to do with hidden key.
sql/handler.h:
  Updated comments to about HA_PRIMARY_KEY_REQUIRED_FOR_POSITION.

      
Added some code to try to find the mysql command line in the most 
common places and stop if it's not there.

The problem there is that HAVING condition evaluates const
parts of condition despite the condition has references
on aggregate functions. Table t1 became const tables
after make_join_statistics and table1.pk = 1, HAVING is
transformed into MAX(1) < 7 and taken away from HAVING.
The fix is to skip evaluation of HAVING conts parts if
HAVING condition has references on aggregate functions.


mysql-test/r/having.result:
  test case
mysql-test/t/having.test:
  test case
sql/sql_select.cc:
  skip evaluation of HAVING conts parts if
  HAVING condition has references on aggregate functions.

The handler function for reading one row from a specific index
was not optimized in the partitioning handler since it
used the default implementation.

No test case since it is performance only, verified by hand.

sql/ha_partition.cc:
  Implemented a optimized version of index_read_idx_map
  for the case when find flag == HA_READ_KEY_EXACT,
  which is the common case.
sql/ha_partition.h:
  Declared ha_partition::index_read_idx_map

Fix the memory leak

Since the original fix for this bug lowercases the search pattern it's not a 
good idea to copy the search pattern to the output instead of the real table 
name found (since, depending on the case mode these two names may differ in 
case).
Fixed the infrmation_schema.test failure by making sure the actual table 
name of an inoformation schema table is passed instead of the lookup pattern
even when the pattern doesn't contain wildcards.

           due to GCC preprocessor change

Temporary workaround: disable abi_check if GCC >= 4.5

The atomic operations implementation on 5.1 has a few problems,
which might cause tests to abort randomly. Since no code in 5.1
uses atomic operations, simply remove the code.

Some test cases set ANSI_QUOTES in sql_mode.
So we have to use single quotes to quote literal strings.

DROP USER 
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave 
executes the log event, 'CURRENT_USER()' is expand to the user of slave 
SQL thread, but SQL thread's user name always NULL. This breaks the replication.

After this patch, session's user will be written into query log events 
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.


mysql-test/include/diff_tables.inc:
  Expend its abilities.
  Now it can diff not only in sessions of 'master' and 'slave', but 
  other sessions as well.
sql/log_event.cc:
  session's user will be written into Query_log_event, if is_current_user_used() is TRUE.
  On slave SQL thread, Only thd->invoker is written into Query_log_event,
  if it exists.
sql/sql_acl.cc:
  On slave SQL thread, grantor should copy from thd->invoker, if it exists
sql/sql_class.h:
  On slave SQL thread, thd->invoker is used to store the applying event's
  invoker.

class is mostly empty, initialize the base class explicitly in
the copy constructor.

If bzero is not available, resort to memset. Also, remove dead
bzero.c