Problem:

The "Slave I/O thread couldn't register on master" error sporadically
occurred in replication tests because the slave I/O thread got
killed by STOP SLAVE before or while registering on master.

Fixed by checking the state of the I/O thread, and issueing
the error only if it was not explicitely killed by a user.

into  polly.(none):/home/kaa/src/opt/bug31742/my51-bug28550

an error, asserts server

In case of a fatal error during filesort in find_all_keys() the error
was returned without the necessary handler uninitialization.
Fixed by changing the code so that handler uninitialization is performed
before returning the error.

into  polly.(none):/home/kaa/src/opt/bug28550/my51-bug28550

  
Since, as of MySQL 5.0.15, CHAR() arguments larger than 255 are converted into multiple result bytes, a single CHAR() argument can now take up to 4 bytes. This patch fixes Item_func_char::fix_length_and_dec() to take this into account.
  
This patch also fixes a regression introduced by the patch for bug21513. As now we do not always have the 'name' member of Item set for Item_hex_string and Item_bin_string, an own print() method has been added to Item_hex_string so that it could correctly be printed by Item_func::print_args().

move 'table_collation' field filling outside of if(file) condition
because this field has 'OPEN_FRM_ONLY' attribute

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

updated result files

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.0-opt

issue an error if string has illegal characters

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31156-5.1-opt

  Fixed dbug macros usage errors

into  magare.gmz:/home/kgeorge/mysql/work/B31156-5.1-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31156-5.0-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31440-5.1-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31440-5.0-opt

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  magare.gmz:/home/kgeorge/mysql/work/B31440-5.1-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31440-5.0-opt

into  mysql.com:/home/hf/work/31155/my51-31155

into  mysql.com:/home/hf/work/31155/my51-31155

into  mysql.com:/home/hf/work/31155/my50-31155

into  mysql.com:/home/hf/work/31155/my51-31155

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

Bug#30982 CHAR(..USING..) can return a not-well-formed string
Bug#30986 Character set introducer followed by a HEX string can return bad result
check_well_formed_result moved to Item from Item_str_func
fixed Item_func_char::val_str for proper ucs symbols converting
added check for well formed strings for correct conversion of constants with underscore
charset

The special case with NULL as a regular expression
was handled at prepare time. But in this special case
the item was not marked as fixed. This caused an assertion
at execution time.
Fixed my marking the item as fixed even when known to 
return NULL at prepare time.

                  precision > 0 && scale <= precision'.

A sign of a resulting item of the IFNULL function was not
updated and the maximal length of this result was calculated
improperly. Correct algorithm was copy&pasted from the IF
function implementation.

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.0-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

added variables relay_log, relay_log_index, relay_log_info_file to init_vars[]
to make them visible within SHOW VARIABLES