Added better comment for perceived problem with fix for Bug #8753 Invalid schema object version after dropping index

Extra fix for perceived problem with fix for Bug #8753 Invalid schema object version after dropping index

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

  InnoDB needs longer start time for second slave on slow hosts

  If MySQL wrote to its binlog, but for some reason trx->update_undo and trx->insert_undo were NULL in InnoDB, then trx->commit_lsn was garbage, and InnoDB could assert in the log flush of trx_commit_complete_for_mysql() (Bug #9277)

  If MySQL wrote to its binlog, but for some reason trx->update_undo and trx->insert_undo were NULL in InnoDB, then trx->commit_lsn was garbage, and InnoDB could assert in the log flush of trx_commit_complete_for_mysql() (Bug #9277)

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

  Made --timer work
mtr_cases.pl:
  Added option --reorder to get less server restarts
mysql-test-run.pl:
  Added option --reorder to get less server restarts
  Moved do_before_start_master() not to remove binlog files unless restarted
  Made --timer work
  Slave was incorrectly writing log to error log

into mysql.com:/M41/mysql-4.1

  Added a test case for bug #8617.
sql_select.cc:
  Fixed bug #8617.
  Queries with ROLLUP and LIMIT n returned more than n rows
  if SQL_CALC_FOUND_ROWS was used.

into frost.snake.net:/Volumes/frost2/MySQL/bk/mysql-4.1

into frost.snake.net:/Volumes/frost2/MySQL/bk/mysql-4.0

into frost.snake.net:/Volumes/frost2/MySQL/bk/merge-4.1

into quadxeon.mysql.com:/nfstmp1/guilhem/mysql-4.1-4xeon

into quadxeon.mysql.com:/nfstmp1/guilhem/mysql-4.0-4xeon

When we come to create these, they may already exist and it's necessary to delete these old, useless copies.

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

  Added a test for bug #8615.
sql_select.cc:
  Fixed bug #8615.
  This fix only removed the cause of the reported crash.
  It does not resolve other problems of rollup queries
  with DISTINCT. They were fixed in the previous patch 
  for bug 8616.

BUG#9123 is solved earlier than this patch though.

the time spent in the various steps.

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

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

not always correct for NULL values.
Now they always result a non NULL value even
the argument is NULL. It is more usefull for 
debugging purposes.

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

fixed result_field support of Item_ref

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

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