for --init-rpl-role.

Problem: There are two variables involved in this issue,
rpl_status and rpl_role_type. The former is an array containing
the description of the possible values for the latter.

rpl_status is declared as an enumeration and is stored in a 4
bytes integer. On the other hand, my_getopt, reads enum values
into a ulong:

  *(ulong*)value= arg;

This is overwriting the memory used for rpl_role_type, 
corrupting the first entry in the array.

Fix: We fix this by re-declaring rpl_status as a ulong, so that it
has space to accommodate the value "parsed" in my_getopt .

with concurrent lock/unlock tables

Approved by Marko

The bug happened only on 5.1

After ALTER TABLE which changed only table's metadata, row-based
binlog sometimes got corrupted since the tablemap was unexpectedly
set to 0 for subsequent updates to the same table.

ALTER TABLE which changed only table's metadata always reset
table_map_id for the table share to 0. Despite the fact that
0 is a valid value for table_map_id, this step caused problems
as it could have created situation in which we had more than
one table share with table_map_id equal 0. If more than one
table with table_map_id are 0 were updated in the same statement,
updates to these different tables were written into the same
rows event. This caused slave server to crash.

This bug happens only on 5.1. It doesn't affect 5.5+.

This patch solves this problem by ensuring that ALTER TABLE
statements which change metadata only never reset table_map_id
to 0. To do this it changes reopen_table() to correctly use
refreshed table_map_id value instead of using the old one/
resetting it.

Removed option file and changed result file.

Print an error message to stderr an get rid of the assertion.

Approved by: Jimmy Yang (over IM)

When slave executes a transaction bigger than slave's max_binlog_cache_size,
slave will crash. It is caused by the assert that server should only roll back
the statement but not the whole transaction if the error ER_TRANS_CACHE_FULL 
happens. But slave sql thread always rollbacks the whole transaction when
an error happens.
            
Ather this patch, we always clear any error set in sql thread(it is different
from the error in 'SHOW SLAVE STATUS') and it is cleared before rolling back
the transaction.

Fix assorted compiler warnings.

 Bug#55744 GROUP_CONCAT + CASE + ucs return garbage
revealed problems in how character set aggregation
code works with prepared statements.

This patch fixes (hopefully) the problems.

Due to the extent of aliasing violations in the MySQL source
code, at this time it is safer to disable strict aliasing related
optimizations in release builds.

As of this patch, only GCC enables strict aliasing by default.
Hence, use the -fno-strict-aliasing option to disable the
aliasing rules.

Adding a comment to scheduler_types on
the default values used.

The server contained code for the server variable and
option thread_pool_size, but this server variable where
not used anywhere.

The variable is probably remains from backporting too
much from 6.0 (specifically, the thread pool
implementation was not backported from 6.0, which this
variable is associated with).

This patch eliminates the variable from the server.

Only wait for a single debug signal at a time as the signal state
is global. Also, do not activate the query cache debug sync points
if the thread has no associated THD session.

Buffer overrun when trying to format DBL_MAX

In calvin.sun@oracle.com-20101005183830-p81bemgffq8l2en9 the default
value of innodb_file_per_table was changed from 1 to 0.

engine is not available. We need to add loose prefix
to example load option.

        now do no initializations for the --help.
        Do it for --verbose --help though.

per-file comments:
  sql/mysqld.cc
Bug#30025 Mysqld prints out warnings/errors being run with --no-defaults --help
        quit with the help message at once as --help was given

        Issue an error if user specifies multiple commands to run.
        Also there was an unnoticed bug that DO_CHECK was actually 0 which lead
        to wrong actions in some cases.
        The mysqlcheck.test contained commands with the suspicious meaning
        for the above reason. Extra commands removed from there.

per-file commands:
  client/mysqlcheck.c
Bug#35269      mysqlcheck behaves different depending on order of parameters
        Drop with an error if multiple commands.
  mysql-test/r/mysqlcheck.result
Bug#35269      mysqlcheck behaves different depending on order of parameters
        result completed.
  mysql-test/t/mysqlcheck.test
Bug#35269      mysqlcheck behaves different depending on order of parameters
        testcase added.
        not-working commands removed from some mysqlcheck calls.

Fix warnings related to the use of the deprecated gets() function
and passing NULL to non-pointer argument of the sys_var constructor.

Move Query_cache_wait_state declaration out of a debug block.

The problem was that threads waiting on the query cache lock
are not easily seen due to the lack of a state indicating that
the thread is waiting on the said lock. This made it difficult
for users to quickly spot (for example, via SHOW PROCESSLIST)
a query cache contention problem.

The solution is to update the thread state when the query cache
lock needs to be acquired. Whenever the lock is to be acquired,
the thread state is updated to "Waiting for query cache lock"
and is reset once the lock is granted or the wait is interrupted.
The intention is to make query cache related hangs more evident.

To further investigate query cache related locking problems, one
may use PERFORMANCE_SCHEMA to track the overhead associated with
the locking bits and determine which particular lock is being a
contention point.

The coalesce function returned DATETIME type due to a DATETIME argument, but
since it's not a date/time function it can't return correct int value for
it. Nevertheless Item_datetime_cache was chosen to cache coalesce's result
and that led to a wrong result.

Now Item_datetime_cache is used only for those function that could return
correct int representation of DATETIME values.

      
The error message for ER_SLAVE_HEARTBEAT_VALUE_OUT_OF_RANGE was
hard coded. Additionally, the same error was used in three
separate error symptoms: 1. when heartbeat period exceeds the
value of slave_net_timeout, 2. when it is smaller than 1
milisecond and 3. when it was not in range, ie, either negative
or greater than the maximum allowed.
      
We fix this by splitting into three distinct errors and by
removing the message from the source code and moving it to the
errmsg-utf8.txt file.