Fix assorted compiler warnings.

Tag or remove unused arguments and variables.

Ensure that fdatasync is properly declared as on Mac OS X, the
function is available but there is no prototype. Also, port a
fix for a warning from the InnoDB plugin over to the builtin. 

Tag unused arguments.
      
Approved by: Marko (via IRC)

Tag unused arguments.

Approved by: Marko (via IRC)

Fix assorted compiler warnings on Mac OS X.

           data dictionary confusion

On file systems with case insensitive file names, and
lower_case_table_names set to '2', the server could crash
due to a table definition cache inconsistency.  This is 
the default setting on MacOSX, but may also be set and
used on MS Windows.

The bug is caused by using two different strategies for
creating the hash key for the table definition cache, resulting
in failure to look up an entry which is present in the cache,
or failure to delete an existing entry.  One strategy was to
use the real table name (with case preserved), and the other
to use a normalized table name (i.e a lower case version).

This is manifested in two cases.  One is  during 'DROP DATABASE', 
where all known files are removed.  The removal from
the table definition cache is done via a generated list of
TABLE_LIST with keys (wrongly) created using the case preserved 
name.  The other is during CREATE TABLE, where the cache lookup
is also (wrongly) based on the case preserved name.
   
The fix was to use only the normalized table name when
creating hash keys.

           (variables_debug fails)

The problem was that "SET GLOBAL debug" could cause a crash on Solaris.
The crash happened if the server failed to open the trace file given in 
the "SET GLOBAL debug" statement. This caused an error message to be
printed to stderr containing the process name. However, printing to
stderr crashed the server since the pointer to the process name had
not been initialized.

This patch fixes the problem by initializing the process name 
properly when doing "SET GLOBAL debug".

No test case added as this bug was repeatable with existing test
coverage in variables_debug.test.

After the fix for
Bug #55077 Assertion failed: width > 0 && to != ((void *)0), file .\dtoa.c
we no longer try to allocate a string of length 'field_length'
so the asserts are relevant only for ZEROFILL columns.

Only test case is merged, as the fix was already
present in 5.5 code

No conflicts

Enable the MySQL maintainer-specific development environment
(which add various warning related options to the compiler
flags) if debugging support is enabled.

Follow-up for bug#36742: changed results for test ipv4_as_ipv6 because hostname is case-insensitive.

because currently hostname stored in db in lowercase.

For crash testing: kill the server without generating core file.

include/my_dbug.h
  Use kill(getpid(), SIGKILL) which cannot be caught by signal handlers.
  All DBUG_XXX macros should be no-ops in optimized mode, do that for DBUG_ABORT as well.
sql/handler.cc
  Kill server without generating core.
sql/log.cc
  Kill server without generating core.

For crash testing: kill the server without generating core file.

include/my_dbug.h
  Use kill(getpid(), SIGKILL) which cannot be caught by signal handlers.
  All DBUG_XXX macros should be no-ops in optimized mode, do that for DBUG_ABORT as well.
sql/handler.cc
  Kill server without generating core.
sql/log.cc
  Kill server without generating core.

          replication aborts

When recieving a 'SLAVE STOP' command, slave SQL thread will roll back the
transaction and stop immidiately if there is only transactional table updated,
even through 'CREATE|DROP TEMPOARY TABLE' statement are in it. But These
statements can never be rolled back. Because the temporary tables to the user
session mapping remain until 'RESET SLAVE', Therefore it will abort SQL thread
with an error that the table already exists or doesn't exist, when it restarts
and executes the whole transaction again.

After this patch, SQL thread always waits till the transaction ends and then stops,
if 'CREATE|DROP TEMPOARY TABLE' statement are in it.

The thing is that the following attributes are fixed (remembered) when a trigger
is created:
  - character_set_client
  - character_set_results
  - collation_connection

There are two triggers created in mysql-test/include/mtr_warnings.sql.
They were created using "current default" character set / collation.
is_triggers.test shows definition of these triggers including recorded
character set information.

The problem was that if "current default" changed, the recorded character
set information was not accurate.

There might be two ways to fix that:
  a) update is_triggers.test so that it does not put character-set information
     into result-file;
  b) update mtr_warnings.sql so that the triggers are created using
     hard-coded character sets.

This patch implements option b).

The root of the problem is that to interrupt a slave SQL thread
wait, the STOP SLAVE implementation uses thd->awake(THD::NOT_KILLED).
This appears as a spurious wakeup (e.g. from a sleep on a
condition variable) to the code that the slave SQL thread is
executing at the time of the STOP. If the code is not written
to be spurious-wakeup safe, unexpected behavior can occur. For
the reported case, this problem led to an infinite loop around
the interruptible_wait() function in item_func.cc (SLEEP()
function implementation).  The loop was not being properly
restarted and, consequently, would not come to an end. Since the
SLEEP function sleeps on a timed event in order to be killable
and to perform periodic checks until the requested time has
elapsed, the spurious wake up was causing the requested sleep
time to be reset every two seconds.

The solution is to calculate the requested absolute time only
once and to ensure that the thread only sleeps until this
time is elapsed. In case of a spurious wake up, the sleep is
restarted using the previously calculated absolute time. This
restores the behavior present in previous releases. If a slave
thread is executing a SLEEP function, a STOP SLAVE statement
will wait until the time requested in the sleep function
has elapsed.

when checking the ABI with the C Preprocessor. Also, add the
new hearders to the cmake based ABI check.

Some platforms don't work with 4 * STACK_MIN_SIZE.
Thus, reverting back to 8 * STACK_MIN_SIZE and waiting for another fix.

latest mysql-5.1-bugteam.

latest mysql-5.1-bugteam.

to fix an sp-error.test failure on Sun Sparc system.