Date field was declared as not null, thus expression 'datefield is null'
was always false. For SELECT special handling of such cases is used. 
There 'datefield is null' converted to 'datefield eq "0000-00-00"'.

In mysql_update() before creation of select added remove_eq_conds() call.
It makes some optimization of conds and in particular performs conversion
from 'is null' to 'eq'. 
Also remove_eq_conds() makes some evaluation of conds and if it founds that
conds is always false then update statement is not processed further.
All this allows to perform some update statements process faster due to
optimized conds, and not wasting resources if conds known to be false. 

  Added MTR_BUILD_THREAD to control the port range

into mysql.com:/Users/kent/mysql/bk/mysql-4.1

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

options to the wrong value. (Bug #12925)

into moonbone.local:/work/14016-bug-4.1-mysql

collation

By default constant strings in second parameter of date_time() have case
insensitive collation. Because of this expressions date_format(f,'%m') and 
date_format(f,'%M') wrongly becomes equal, which results in choosing wrong 
column to sort by.

Now if second parameter of date_format() is constant then it's collation is 
changed to case sensitive.

into moonbone.local:/work/13392-bug-4.1-mysql

VALUES() can only refer to table insert going to. 
But Item_insert_value::fix_fields() were passing to it's arg full table list,
This results in finding second column which shouldn't be found, and
failing with error about ambiguous field.

Item_insert_value::fix_fields() now passes only first table of full table
list.

into mysql.com:/M41/mysql-4.1

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-4.1

into mysql.com:/Users/kent/mysql/bk/mysql-4.1

  Option to set environment variable MTR_BUILD_THREAD to a small
  number, from what mysql-test-run calculate port numbers that
  will not conflict with other runs with different thread num

into mysql.com:/home/psergey/mysql-4.1-nulls-stats-r2

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

  select distinct char(column) fails with utf8
ctype_utf8.result, ctype_utf8.test:
  Adding test case
sql_yacc.yy:
  Adding new syntax.
item_strfunc.h:
  Fixing wrong max_length calculation.
  Also, adding CHAR(x USING charset),
  for easier migrating from 4.1 to 5.0,
  according to Monty's suggestion.

into  perch.ndb.mysql.com:/home/jonas/src/mysql-4.1-push

added "nulls_ignored" index statistics collection method for MyISAM tables.
(notification trigger: this is about BUG#9622).

into  neptunus.(none):/home/msvensson/mysql/mysql-4.1

  Bug#13238 mysqldump and mysqladmin hangs
  Avoid recursion into init_available_charsets.
  Serg's version didn't work for me: I got 
  double mutex locking.
  Pushing this version instead
  (It was approved by Serg anyway)

into  mysql.com:/home/alexi/dev/mysql-4.1-4375

 during replication.
 Modified my_dir(). Now this function skips hidden and system
 files which sometimes are created by Windows.
 NOTE. The fix is similar to the previuos one (05 July 2004)
 except for correct setting of the 'attrib' variable value
 (within the previous fix this variable was left uninitialized
 when my_dir() was called with My_flags & MY_WANT_STAT == 0).

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

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

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

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-4.1

into mysql.com:/home/psergey/mysql-4.1-bug12915-r2

into  perch.ndb.mysql.com:/home/jonas/src/mysql-4.1-push

into  perch.ndb.mysql.com:/home/jonas/src/mysql-4.1-push

  Disable tests of lock upgrade paths that are currently unsupported

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