Item_func_group_concat::fix_fields() set maybe_null flag to 0, and set it to
1 only if some of it's arguments may be null. When used in subquery in tmp 
table created field which can't be null. When no data retireved result field
have to be set to null and error mentioned in bug report occurs. Also this 
bug can occur if selecting from not null field in empty table.

Function group_concat now marked maybe_null from the very beginning not only
if some of it's argument may be null.

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  zim.(none):/home/brian/mysql/mysql-4.1

into  mysql.com:/usr/home/ram/work/4.1.b9613

Item::tmp_table_field_from_field_type() and create_tmp_field_from_item()
was converting string field to blob depending on byte-wise length instead of
character length, which results in converting valid varchar string with
length == 86 to longtext.

Made that functions above take into account max width of character when
converting string fields to blobs.

into  mysql.com:/usr/home/ram/work/4.1.b9613

into  mysql.com:/home/mydev/mysql-4.1-4100

into  mysql.com:/usr/home/ram/work/4.1.b9613

into  eel.(none):/home/jonas/src/mysql-4.1-push

into  eel.(none):/home/jonas/src/mysql-4.1-push

 fix typo

into  mysql.com:/home/mydev/mysql-4.1-4100

  Found one more missing DBUG_ENTER. compile-pentium-debug-max does not enable blackhole on 4.1!

into  zim.(none):/home/brian/mysql/mysql-4.1

  Added missing DBUG enter, compiled and tested on production with debug-max
  build (my regular build missed the previous errors friday)

Changeset:
 Added missing DBUG_ENTER, compiled and tested on production with debug-max
 build!

into  mysql.com:/home/mydev/mysql-4.1-4100

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

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

Skipping deleted records instead of breaking the loop
during checksum calculation.

Handle temporary tables like permanent tables: If the storage engine
cannot truncate, delete instead.

Supplied the default database name for ALTER TABLE ... RENAME 
for the new table instead of the old tables db like we do for 
other ALTERs.

Changed end-space comparison so that the key is not used past
its end. This is due to the new end-space behaviour in 4.1.
See also bug 6151 and 9188.

  Bug#12371 executing prepared statement fails (illegal mix of collations)
  After review fixes.

into  mysql.com:/usr/home/bar/mysql-4.1.b12371

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

  Make ports configurable from environment for test

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

  Reorder out-of-order system variables.

  Reorder out-of-order status variables.

into deer.(none):/home/hf/work/mysql-4.1.clean

into  radha.local:/Users/patg/mysql-build/mysql-4.1