returns unexpected result

If:
  1. a table has a not nullable BIT column c1 with a length
     shorter than 8 bits and some additional not nullable
     columns c2 etc, and
  2. the WHERE clause is like: (c1 = constant) AND c2 ...,
the SELECT query returns unexpected result set.


The server stores BIT columns in a tricky way to save disk
space: if column's bit length is not divisible by 8, the
server places reminder bits among the null bits at the start
of a record. The rest bytes are stored in the record itself,
and Field::ptr points to these rest bytes.

However if a bit length of the whole column is less than 8,
there are no remaining bytes, and there is nothing to store in
the record at its regular place. In this case Field::ptr points
to bytes actually occupied by the next column in a record.
If both columns (BIT and the next column) are NOT NULL,
the Field::eq function incorrectly deduces that this is the
same column, so query transformation/equal item elimination
code (see build_equal_items_for_cond) may mix these columns
and damage conditions containing references to them.


mysql-test/r/type_bit.result:
  Added test case for bug #37799.
mysql-test/t/type_bit.test:
  Added test case for bug #37799.
sql/field.h:
  1. The Field::eq function has been modified to take types of
  comparing columns into account to distinguish between BIT and
  not BIT columns referencing the same bytes in a record.
  
  2. Unnecessary type comparison has been removed from the
  Field_bit::eq function (moved to Field::eq).

      
When switching to indexed ORDER BY we must be sure to reset the index read
flag if we are switching from a covering index to non-covering.

mysql-test/r/subselect.result:
  Bug#37548: test case
mysql-test/t/subselect.test:
  Bug#37548: test case
sql/sql_select.cc:
  Bug#37548: update the index read flag if the index for indexed ORDER BY is not
      covering.

used causes server crash.
      
When the loose index scan access method is used values of aggregated functions
are precomputed by it. Aggregation of such functions shouldn't be performed
in this case and functions should be treated as normal ones.
The create_tmp_table function wasn't taking this into account and this led to
a crash if a query has MIN/MAX aggregate functions and employs temporary table
and loose index scan.
Now the JOIN::exec and the create_tmp_table functions treat MIN/MAX aggregate
functions as normal ones when the loose index scan is used.


mysql-test/r/group_min_max.result:
  Added a test case for the bug#38195.
mysql-test/t/group_min_max.test:
  Added a test case for the bug#38195.
sql/sql_select.cc:
  Bug#38195: Incorrect handling of aggregate functions when loose index scan is
  used causes server crash.
  The JOIN::exec and the create_tmp_table functions treat MIN/MAX aggregate
  functions as normal ones when the loose index scan is used.

            tables open

When executing a DROP DATABASE statement in ROW mode and having temporary
tables open at the same time, the existance of temporary tables prevent
the server from switching back to row mode after temporarily switching to
statement mode to handle the logging of the statement.

Fixed the problem by removing the code to switch to statement mode and added
code to temporarily disable the binary log while dropping the objects in the
database.


mysql-test/extra/binlog_tests/database.test:
  Added test to ensure that DROP DATABASE does not affect the replication mode.
sql/sql_db.cc:
  Removed code that clears the current_stmt_binlog_row_based flag.
  Added code to disable the binary log while dropping the objects
  in a database.

post push fix

Updated partition_symlink since different error behavior
if embedded (or not partitioned)

mysql-test/r/partition_symlink.result:
  Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY
  
  updated result file
mysql-test/t/partition_symlink.test:
  Bug#32167 another privilege bypass with DATA/INDEX DIRECTORY
  
  Fix for embedded

Typo fixed.
No test case as we actually don't use rtree_get_first() 
and rtree_get_next() at present.

Problem: data consistency check (maximum record length) for a correct
MyISAM table with CHECKSUM=1 and ROW_FORMAT=DYNAMIC option 
may fail due to wrong inner MyISAM parameter. In result we may 
have the table marked as 'corrupted'. 

Fix: properly set MyISAM maximum record length parameter.


myisam/mi_create.c:
  Fix for bug #37310: 'on update CURRENT_TIMESTAMP' option crashes the table
  
  Use HA_OPTION_PACK_RECORD instead of HA_PACK_RECORD (typo?) 
  calculating packed record length.

mysql-test/include/wait_for_slave_sql_error_and_skip.inc:
  include/start_slave.inc not exist yet, changed to start slave and source include/wait_for_slave_to_start.inc
mysql-test/suite/rpl/r/rpl_filter_tables_not_exist.result:
  update result

- Use the compiler's default copy constructor for QUICK_RANGE_SELECT. 
  bcopy(this, copy, ...) call caused some odd action on gcc-4.1.2 on x86_64

sql/opt_range.cc:
  BUG#36639: subselect.test crashes on 64 bit pentium4 when compiled for valgrind
  - Set QUICK_SELECT_DESC not to use MRR implementation (code moved to here
    from opt_range.h)
sql/opt_range.h:
  BUG#36639: subselect.test crashes on 64 bit pentium4 when compiled for valgrind
  - Use the compiler's default copy constructor for QUICK_RANGE_SELECT. 
    bcopy(this, copy, ...) call caused some odd action on gcc-4.1.2 on x86_64

Dumping information about locks in use by sending a SIGHUP signal
to the server or by invoking the "mysqladmin debug" command may
lead to a server crash in debug builds or to undefined behavior in
production builds.

The problem was that a mutex that protects a lock object (THR_LOCK)
might have been destroyed before the lock object was actually removed
from the list of locks in use, causing a race condition with other
threads iterating over the list. The solution is to destroy the mutex
only after removing lock object from the list.

mysys/thr_lock.c:
  Destroy the mutex that protects the lock object only after removing
  the lock object from the list of locks in use.

plugin_dir option backported from 5.1

mysql-test/r/udf.result:
  result fix
sql/mysql_priv.h:
  opt_plugin_dir and opt_plugin_dir_ptr declared.
sql/mysqld.cc:
  'plugin_dir' option added
sql/set_var.cc:
  'plugin_dir' option added.
sql/sql_udf.cc:
  opt_plugin_dir added to the udf->dl path. Warn if it's not specified.
sql/unireg.h:
  PLUGINDIR defined.

Fixing non-deterministic test results:
the number of spaces in FLOAT/DOUBLE output could 
vary between different platforms.