Now thd->mem_root is a pointer to thd->main_mem_root and THR_MALLOC is a pointer to thd->mem_root.
This gives us the following benefits:
- Allow us to easily detect if arena has already been swapped before (this fixes a bug in setup_conds() where arena was swaped twice in some cases)
- Faster swaps of arenas (as we don't have to copy the whole MEM_ROOT)
- We don't anymore have to call my_pthread_setspecific_ptr(THR_MALLOC,...) to change where memory is alloced. Now it's enough to set thd->mem_root

into mysql.com:/M41/mysql-4.1

  My previous change that "set @A=NULL" doesn't change charset
  fixed 'Bug #6321' as well. Prove with a new test that
  FIELD(<uservariable content NULL>, ...) now works fine too.

_all_ versions. It tries to remove "Docs/Images/Makefile*" as part of the actions to
correct bug number 6350. If the source tree does not contain a dummy file matching
that pattern, this "rm" will fail, and so "Bootstrap" will fail.
The "Makefile.am" introduced with this changeset is identical to the one that will
arrive here when "joerg:1.2057" is propagated from 4.0,
so this separate introduction here is just to allow "Bootstraps" in the meantime.

character set with NULL, @A should be latin2
after this query sequence:

   SET @A=_latin2'string';
   SET @A=NULL;

I.e. the second query should not change the charset
to the current default value, but should keep the
original value assigned during the first query.
In order to do it, we don't copy charset
from the argument if the argument is NULL
and the variable has previously been initialized.

into mysql.com:/usr/local/home/marty/MySQL/test/mysql-4.1

into rurik.mysql.com:/home/igor/mysql-4.1

  Bug #6351 make test failure "Unknown character set"
  UCS2 related tests were moved into ctype_ucs.

  - 'mysqldump --help' comment that --xeh-blob
    doesn't work with --extended-inserts was removed.
    It does work now. Thanks to Lachlan
    who noticed this wrong help message.
  - Switched to use the recently introduced
    mysql_hex_string() instead of slow sprintf().
    Thanks to Sinisa for the idea.
  - 'mysqldump --hex-blob' dumps in HEX not only
    BLOBs but also BINARY(x) columns. 
    Thanks to Paul.

  Minor clean-ups

into rurik.mysql.com:/home/igor/dev/mysql-4.1-0

  Added a case for bug #6365.
item_cmpfunc.cc:
  Fixed bug #6365 : Server crashed when list of values
  in IN predicate contains NULL while the tested field is
  of the character type and not of the default set;
  e.g. when f in 'f IN (NULL,'aa') belongs to binary
  character set, while the default character set is latin1.

  Missing initialized for "lengths" element.
  ,

(prepared staements)": adding the test case to close the bug
(the bug was fixed along with other conversion incompatibilities 
in 4.1.7)

code check is wrong".

into mysql.com:/home/wax/mysql/mysql-4.1mysqltest

into hundin.mysql.fi:/home/marko/j/mysql-4.1

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

  changed to use new switch

  write_row(): document the ALTER TABLE tweak better,
  and commit every n*10000 rows, not n*10000-1 rows.

into mysql.com:/space/pekka/ndb/version/my41

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

  ugly fix for 'quadita2' ia64 icc -O1

into mysql.com:/usr/local/home/marty/MySQL/test/mysql-4.1

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

into gw.mysql.r18.ru:/usr/home/ram/work/4.1.b6331

  "SHOW CREATE TABLE" mysql-4.0 and mysql-3.23 
  compatibiliry mode change:
  Check that a binary collation adds 'binary'
  suffix into a char() column definition in
  mysql40 and mysql2323 modes. This allows
  not to lose the column's case sensitivity
  when loading the dump in pre-4.1 servers.

  Do not print to .err log about discarding ibuf entries in DISCARD TABLESPACE; removed compiler warning about unused variable

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

into mysql.com:/home/bk/b5551-4.1-v4

The idea of the fix is that the administrative statements 
OPTIMIZE TABLE, REPAIR TABLE and ANALYZE TABLE should not 
generate binlog errors if there is no errors on the master.