If we have DELETE with always true WHERE clause we should not use 
optimized delete_all_rows() method for tables with DELETE triggers,
because in this case we will lose side-effect of deletion.

into mysql.com:/home/pem/work/mysql-5.0

into mysql.com:/M50/mysql-5.0

into mysql.com:/home/pem/work/mysql-5.0

fixed

into rurik.mysql.com:/home/igor/dev/mysql-5.0-0

  Added test cases for bug #6474.
sql_select.cc:
  Fixed bug #6474. A wrong result was returned when a query
  contained the same equality of the form field=const on
  different AND levels.

into poseidon.ndb.mysql.com:/home/tomas/mysql-5.0

into poseidon.ndb.mysql.com:/home/tomas/mysql-5.0

into gw.mysql.r18.ru:/usr/home/ram/work/5.0

       bug #6515: count(distinct...) crashes the server)

into mysql.com:/home/my/mysql-5.0

into sanja.is.com.ua:/home/bell/mysql/bk/mysql-5.0

into sergbook.mylan:/usr/home/serg/Abk/mysql-5.0

into sanja.is.com.ua:/home/bell/mysql/bk/mysql-5.0

Added push_back(void *, MEM_ROOT *) to make some list-handling code easier that needs to be allocated in a different mem-root
(Before one had to change thd->mem_root ; push_back(); restore mem_root.

into sergbook.mylan:/usr/home/serg/Abk/mysql-5.0

locks all rows (BUG #3300). When using innobase_locks_unsafe_for_binlog
option InnoDB does not take locks for those rows which do not
belong to the result set or werent changed by the query. This fix removes
unnecessary locks also from SELECT and DELETE queries.

    test_ro("999999999999999999999.999", 0, CEILING);
    test_da("5", "-6.0");
ignore:
  added gdbinit

into sanja.is.com.ua:/home/bell/mysql/bk/work-view-5.0

into sanja.is.com.ua:/home/bell/mysql/bk/work-update-5.0

into mysql.com:/home/my/mysql-4.1

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