Remove functions that no longer needed
Fix warning suppressions

mysql-test/suite/rpl/t/rpl_semi_sync.test:
  Fix warning suppressions
plugin/semisync/semisync_slave.cc:
  Remove functions that no longer needed
plugin/semisync/semisync_slave.h:
  Remove functions that no longer needed

Add an option to control whether the master should keep waiting
until timeout when it detected that there is no semi-sync slave
available.

The bool option 'rpl_semi_sync_master_wait_no_slave' is 1 by
defalt, and will keep waiting until timeout. When set to 0, the
master will switch to asynchronous replication immediately when
no semi-sync slave is available.

Semi-sync status were not reset by FLUSH STATUS, this was because
all semi-sync status variables are defined as SHOW_FUNC and FLUSH
STATUS could only reset SHOW_LONG type variables.

This problem is fixed by change all status variables that should
be reset by FLUSH STATUS from SHOW_FUNC to SHOW_LONG.

After the fix, the following status variables will be reset by
FLUSH STATUS:
  Rpl_semi_sync_master_yes_tx
  Rpl_semi_sync_master_no_tx

Note: normally, FLUSH STATUS itself will be written into binlog
and be replicated, so after FLUSH STATS, one of
  Rpl_semi_sync_master_yes_tx
  Rpl_semi_sync_master_no_tx
can be 1 dependent on the semi-sync status. So it's recommended
to use FLUSH NO_WRITE_TO_BINLOG STATUS to avoid this.

Errors when send reply to master should never cause the IO thread
to stop, because master can fall back to async replication if it
does not get reply from slave.

The problem is fixed by deliberately ignoring the return value of
slaveReply.

Semi-sync uses an extra connection from slave to master to send
replies, this is a normal client connection, and used a normal
SET query to set the reply information on master, which is visible
to user and may cause some confusion and complaining.

This problem is fixed by using the method of sending reply by
using the same connection that is used by master dump thread to
send binlog to slave. Since now the semi-sync plugins are integrated
with the server code, it is not a problem to use the internal net
interfaces to do this.

The master dump thread will mark the event requires a reply and
wait for the reply when the event just sent is the last event
of a transaction and semi-sync status is ON; And the slave will
send a reply to master when it received such an event that requires
a reply.

Fix for backport into mysql-5.1-rep+2

mysql-test/suite/rpl/r/rpl_stop_middle_group.result:
  the new result file
mysql-test/suite/rpl/t/rpl_stop_middle_group.test:
  renamed from rpl_row_stop_middle_update and added a regression test for bug#45940.

The issue appears when number of heartbeat events non-zero before start of test
block. But really we need to check that no new events has received during test block.
So I did following:
1. Replace absolute values by diff of values
2. Increase heartbeat period from 1.5 to 5 sec

It is backport patch.
This adds new test case for testing affects of some variables to replication.

On sparc, semisync master/slave status is always showed as OFF, this
is fixed by change rpl_semisync_master/slave_status variables from
long to char.

plugin/semisync/semisync_master.cc:
  Change rpl_semisync_master_status variables from long to char
plugin/semisync/semisync_master.h:
  Change rpl_semisync_master_status variables from long to char
plugin/semisync/semisync_slave.cc:
  Change rpl_semisync_slave_status variables from long to char
plugin/semisync/semisync_slave.h:
  Change rpl_semisync_slave_status variables from long to char

This is backport for next-mr.

The patch adds new test cases that cover replication heartbeat testing.

fixing tests results: rpl_ndb_log, rpl_ndb_multi, sp_trans_log; adding replicate-ignore_server_ids specific tests

mysql-test/mysql-test-run.pl:
  Set SEMISYNC_PLUGIN_OPT to '--plugin-dir=' when semi-sync plugins are not found

binlog_tmp_table
rpl_row_sp006_InnoDB
rpl_slave_status

According to Jon's comment, add (at least one of) to the error message.

CHANGE MASTER TO command required the value for RELAY_LOG_FILE to
be an absolute path, which was different from the requirement of
MASTER_LOG_FILE.

This patch fixed the problem by changing the value for RELAY_LOG_FILE
to be the basename of the log file as that for MASTER_LOG_FILE.

Options loaded from config files were added before command line
arguments, and they were parsed together, which could interprete
the following:
option-a
option-b
as --option-a=--option-b if 'option-a' requires a value, and 
caused confusing.

Because all options that requires a value are always given in
the form '--option=value', so it's an error if there is no 
'=value' part for such an option read from config file.

This patch added a separator to separate the arguments from 
config files and that from command line, so that they can be
handled differently. And report an error for options loaded
from config files that requires a value and is not given in the
form '--option=value'.

There were two memory leaks in mysqlbinlog command, one was already
fixed by previous patches, another one was that defaults_argv was
set to the value of argv after parse_args, in which called
handle_options after calling load_defaults and changed the value
of argv, and caused the memory allocated for defaults arguments
not freed.

Fixed the problem by setting defaults_argv right after calling
load_defaults.

There are three internal status for slave I/O thread, both
MYSQL_SLAVE_RUN_NOT_CONNECT and MYSQL_SLAVE_NOT_RUN are reported
as 'No' for Slave_IO_running of command SHOW SLAVE STATUS.

Change MYSQL_SLAVE_RUN_NOT_CONNECT to be reported as 'Connecting'.

When a storage engine failed to initialize before allocated slot number,
the slot number would be 0, and when later finalizing this plugin, it would
accidentally unplug the storage engine currently uses slot 0.

This patch fixed this problem by add a new macro value HA_SLOT_UNDEF to
distinguish undefined slot number from slot 0.

Fix mtr semisync plugin option paths

wait_until_disconnected.inc.

NOTE: Backporting the patch to next-mr.
      
The slave was crashing while failing to execute the init_slave() function.
      
The issue stems from two different reasons:
      
1 - A failure while allocating the master info structure generated a
    segfault due to a NULL pointer.
      
2 - A failure while recovering generated a segfault due to a non-initialized
    relay log file. In other words, the mi->init and rli->init were both set to true
    before executing the recovery process thus creating an inconsistent state as the
    relay log file was not initialized.
      
To circumvent such problems, we refactored the recovery process which is now executed
while initializing the relay log. It is ensured that the master info structure is
created before accessing it and any error is propagated thus avoiding to set mi->init
and rli->init to true when for instance the relay log is not initialized or the relay
info is not flushed.
      
The changes related to the refactory are described below:
      
1 - Removed call to init_recovery from init_slave.
      
2 - Changed the signature of the function init_recovery.
      
3 - Removed flushes. They are called while initializing the relay log and master
    info.
      
4 - Made sure that if the relay info is not flushed the mi-init and rli-init are not
    set to true.
      
In this patch, we also replaced the exit(1) in the fault injection by DBUG_ABORT()
to make it compliant with the code guidelines.

rpl_slave_skip fails randomly on PB2. This patch fixes the failure by
setting explicit wait for SQL thread to stop, instead of the 
wait_for_slave_to_stop mysqltest command, after a start until command 
is executed.

This is a temporary fix.

NOTE: Backporting the patch to next-mr.

NOTE: Backporting the patch to next-mr.

NOTE: Backporting the patch to next-mr.
      
The fix proposed in BUG#35542 and BUG#31665 introduces a performance issue
when fsyncing the master.info, relay.info and relay-log.bin* after #th events.
Although such solution has been proposed to reduce the probability of corrupted
files due to a slave-crash, the performance penalty introduced by it has
made the approach impractical for highly intensive workloads.
      
In a nutshell, the option --syn-relay-log proposed in BUG#35542 and BUG#31665
simultaneously fsyncs master.info, relay-log.info and relay-log.bin* and
this is the main source of performance issues.
      
This patch introduces new options that give more control to the user on
what should be fsynced and how often:
      
   1) (--sync-master-info, integer) which syncs the master.info after #th event;
   2) (--sync-relay-log, integer) which syncs the relay-log.bin* after #th
   events.
   3) (--sync-relay-log-info, integer) which syncs the relay.info after #th
   transactions.
      
   To provide both performance and increased reliability, we recommend the following
   setup:
      
   1) --sync-master-info = 0 eventually the operating system will fsync it;
   2) --sync-relay-log = 0 eventually the operating system will fsync it;
   3) --sync-relay-log-info = 1 fsyncs it after every transaction;
      
Notice, that the previous setup does not reduce the probability of
corrupted master.info and relay-log.bin*. To overcome the issue, this patch also
introduces a recovery mechanism that right after restart throws away relay-log.bin*
retrieved from a master and updates the master.info based on the relay.info:
      
      
   4) (--relay-log-recovery, boolean) which enables a recovery mechanism that
   throws away relay-log.bin* after a crash.
      
However, it can only recover the incorrect binlog file and position in master.info,
if other informations (host, port password, etc) are corrupted or incorrect,
then this recovery mechanism will fail to work.