in combination with IS NULL'
      
As this bug is a duplicate of bug#49322, it also includes test cases
covering this bugreport
      
Qualifying an OUTER JOIN with the condition 'WHERE <column> IS NULL',
where <column> is declared as 'NOT NULL' causes the
'not_exists_optimize' to be enabled by the optimizer.
      
In evaluate_join_record() the 'not_exists_optimize' caused
'NESTED_LOOP_NO_MORE_ROWS' to be returned immediately
when a matching row was found.
      
However, as the 'not_exists_optimize' is derived from
'JOIN_TAB::select_cond', the usual rules for condition guards
also applies for 'not_exist_optimize'. It is therefore incorrect
to check 'not_exists_optimize' without ensuring that all guards
protecting it is 'open'.
      
This fix uses the fact that 'not_exists_optimize' is derived from
a 'is_null' predicate term in 'tab->select_cond'. Furthermore,
'is_null' will evaluate to 'false' for any 'non-null' rows
once all guards protecting the is_null is open.
      
We can use this knowledge as an implicit guard check for the
'not_exists_optimize' by moving 'if (...not_exists_optimize)'
inside the handling of 'select_cond==false'. It will then
not take effect before its guards are open.
      
We also add an assert which requires that a
'not_exists_optimize' always comes together with
a select_cond. (containing 'is_null').

            
Root cause for this bug is that the optimizer try to detect&
optimize the special case:
      
'<field>  BETWEEN c1 AND c1' and handle this as the condition '<field>  = c1'
            
This was implemented inside add_key_field(.. *field, *value[]...)
which assumed field to refer key Field, and value[] to refer a [low...high]
constant pair. value[0] and value[1] was then compared for equality.
            
In a 'normal' BETWEEN condition of the form '<field>  BETWEEN val1 and val2' the
BETWEEN operation is represented with an argementlist containing the
values [<field>, val1, val2] - add_key_field() is then called with
parameters field=<field>, *value=val1.
            
However, if the BETWEEN predicate specified:
            
 1)  '<const1>  BETWEEN<const2>  AND<field>
            
the 'field' and 'value' arguments to add_key_field() had to be swapped.
This was implemented by trying to cheat add_key_field() to handle it like:
            
 2) '<const1>  GE<const2>  AND<const1>  LE<field>'
            
As we didn't really replace the BETWEEN operation with 'ge' and 'le',
add_key_field() still handled it as a 'BETWEEN' and compared the (swapped)
arguments<const1>  and<const2>  for equality. If they was equal, the
condition 1) was incorrectly 'optimized' to:
            
 3) '<field>  EQ <const1>'
            
This fix moves this optimization of '<field>  BETWEEN c1 AND c1' into
add_key_fields() which then calls add_key_equal_fields() to collect 
key equality / comparison for the key fields in the BETWEEN condition.

Created a clear text built in client authentication plugin.
Test case added.
Added a negative test case : a login failure.

Conflicts:
  
  . mysql-test/extra/rpl_tests/rpl_insert_ignore.test
  . mysql-test/suite/rpl/t/disabled.def
  . mysql-test/suite/rpl/t/rpl_insert_ignore.test
  . sql/sql_insert.cc
  . sql/sql_repl.cc

No commit message

Third updated patch - this version also includes copyright notice in added Perl script.
This patch implements a check for such modules at runtime. If modules are not found or unable to load, the test is skipped with 
the following message:
            
            [ skipped ]  Test needs Perl modules DBI and DBD::mysql
            
Checks are done via a helper Perl script which looks for the module in a runtime environment that is as similar to that of the 
mysqlhotcopy script as possible (thus not intended for Windows environments at this time).
The helper script tells mysql-test about the result by writing information to a temporary file that is later read by mysql-test.
See comments in added files (have_dbi_dbd-mysql.inc and checkDBI_DBD-mysql.pl) for details.
The patch also removes the mysqlhotcopy tests from the list of disabled tests.

Do as mysqld_safe: if running mysqld-debug, plugins are in debug subdirs
NB mtr --debug won't work in this context until 47141 is fixed
Also moved read_plugin_defs; no point running this in all worker threads

In SBR, if a statement does not fail, it is always written to the binary
log, regardless if rows are changed or not. If there is a failure, a
statement is only written to the binary log if a non-transactional (.e.g.
MyIsam) engine is updated.

INSERT ON DUPLICATE KEY UPDATE and INSERT IGNORE were not following the
rule above and were not written to the binary log, if then engine was
Innodb.

rb://582 approved by Marko

for external_size
      
rb://581 approved by Marko

There are two calls to read_log_event() on master in mysql_binlog_send().
Each call reads 19 bytes in this test case and the error of the second
read_log_event() is reported to the slave.

The second read_log_event() starts from position 94 (75 + 19) to 113
(75 + 19 + 19). Usually, there are two events in the binary log:

    . 0   - 3   - Header
    . 4   - 105 - Format Descriptor Event
    . 106 - 304 - Query Event

and both reads fail because operations are reading from invalid positions
as expected.

However, mysql_binlog_send() does not use the same IO_CACHE that is used to
write into binary log (i.e. mysql_bin_log.log_file) for the hot binary log.
It opens the binary log file directly by calling open_binlog() and creates a
separated IO_CACHE. So there is a possibly that after a master has flushed
the binary log file, the content has been cached by the filesystem, and has
not updated the disk file. If this happens, then a slave will only see part
of the file, and thus the second read_log_event() will report event truncated
error.

To fix the problem, if the first read_log_event() has failed, we ensure that
the second one will try to read from the same position.

Added --mysqld-env option, propagate via safe_process
Simplified: should be safe to set in parent safe_process after it's started
Addendum: catch cases of --mysqld-env w/o value, assume env.var 
    name never begins with "--"

Fixed the 'show profile source' part of the bug.
Leaving SHOW ENGINE INNODB MUTEX to a separate patch.

trx_get_trx_by_xid(): Invalidate trx->xid after a successful lookup,
so that subsequent callers will not find the same transaction.

The only callers of trx_get_trx_by_xid() will be invoking
innobase_commit_low() or innobase_rollback_trx(), and those code paths
should not depend on trx->xid.

rb://584 approved by Jimmy Yang

that refers to trx_sys_set_ibuf_format().
Change buffer format tagging was never implemented.