The problem in this bug is when we create temporary tables. When
temporary tables are created for unions, there is some 
inferrence being carried out regarding the type of the column.
Whenever this column type is inferred to be REAL (i.e. FLOAT or
DOUBLE), MySQL will always try to maintain exact precision, and
if that is not possible (there are hardware limits, since FLOAT
and DOUBLE are stored as approximate values) will switch to
using approximate values. The problem here is that at this point
the information about number of significant digits is not 
available. Furthermore, the number of significant digits should
be increased for the AVG function, however, this was not properly 
handled. There are 4 parts to the problem:

#1: DOUBLE and FLOAT fields don't display their proper display 
lengths in max_display_length(). This is hard-coded as 53 for 
DOUBLE and 24 for FLOAT. Now changed to instead return the 
field_length.

#2: Type holders for temporary tables do not preserve the 
max_length of the Item's from which they are created, and is 
instead reverted to the 53 and 24 from above. This causes 
*all* fields to get non-fixed significant digits.

#3: AVG function does not update max_length (display length)
when updating number of decimals.

#4: The function that switches to non-fixed number of 
significant digits should use DBL_DIG + 2 or FLT_DIG + 2 as 
cut-off values (Since fixed precision does not use the 'e' 
notation)

Of these points, #1 is the controversial one, but this 
change is preferred and has been cleared with Monty. The 
function causes quite a few unit tests to blow up and they had
to b changed, but each one is annotated and motivated. We 
frequently see the magical 53 and 24 give way to more relevant
numbers.

into  magare.gmz:/home/kgeorge/mysql/autopush/B26794-5.0-opt

Different set of conditions is used to verify
the validity of index definitions over a GEOMETRY
column in ALTER TABLE and CREATE TABLE. 
The difference was on how sub-keys notion validity
is checked.
Fixed by extending the CREATE TABLE condition to
support the cases allowed in ALTER TABLE.
Made the SHOW CREATE TABLE not to display spatial
indexes using the sub-key notion.

into  magare.gmz:/home/kgeorge/mysql/autopush/B26672-5.0-opt

into  olga.mysql.com:/home/igor/dev-opt/mysql-5.0-opt-bug26963

when the column is to be read from a derived table column which 
was specified as a concatenation of string literals.
The bug happened because the Item_string::append did not adjust the
value of Item_string::max_length. As a result of it the temporary 
table column  defined to store the concatenation of literals was 
not wide enough to hold the whole value.

after single-row table substitution could lead to a wrong result set.
The bug happened because the function Item_field::replace_equal_field
erroniously assumed that any field included in a multiple equality
with a constant has been already substituted for this constant.
This not true for fields becoming constant after row substitutions
for constant tables.
 

into  magare.gmz:/home/kgeorge/mysql/autopush/WL3527-5.0-opt-merge

into  moonbone.local:/mnt/gentoo64/work/25373-bug-5.0-opt-mysql

When the SUBSTRING() function was used over a LONGTEXT field the max_length of
the SUBSTRING() result was wrongly calculated and set to 0. As the max_length
parameter is used while tmp field creation it limits the length of the result
field and leads to printing an empty string instead of the correct result.

Now the Item_func_substr::fix_length_and_dec() function correctly calculates
the max_length parameter.

into  moonbone.local:/mnt/gentoo64/work/25373-bug-5.0-opt-mysql

Crash happened because the function get_best_group_min_max detected
joins with ROLLUP incorrectly.

away.

Additional fix for bug#22331. Now Item_field prints its value in the case of
the const field.

into  magare.gmz:/home/kgeorge/mysql/work/WL3527-5.0-opt-merge

         be specified
 5.0 part of the fix. Implements IGNORE INDEX FOR JOIN as a synonym
 of IGNORE INDEX for backward compatibility with the 5.1 fix.

into  magare.gmz:/home/kgeorge/mysql/autopush/B26281-5.0-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B26281-5.0-opt

 Fixed boundry checks in the INSERT() function:
 were one off.

into  olga.mysql.com:/home/igor/mysql-5.0-opt

into  olga.mysql.com:/home/igor/dev-opt/mysql-5.0-opt-bug26661

construct references invalid name.
Derived tables currently cannot use outer references.
Thus there is no outer context for them.
The 4.1 code takes this fact into account while the 
Item_field::fix_outer_field code of 5.0 lost the check that blocks
any attempts to resolve names in outer context for derived tables.

into  mysql.com:/home/hf/work/mrg/mysql-5.0-opt

into  mysql.com:/home/hf/work/mrg/mysql-5.0-opt

into  mysql.com:/home/hf/work/mrg/mysql-5.0-opt

into  mysql.com:/home/hf/work/mrg/mysql-4.1-opt

  Postfix for bug#22331.

into  pilot.blaudden:/home/msvensson/mysql/mysql-4.1-maint

into  pilot.blaudden:/home/msvensson/mysql/mysql-5.0-maint

into  pilot.blaudden:/home/msvensson/mysql/mysql-5.0-maint

comp_err.c:  return ha_checksum from checksum_format_specifier() - more correct, avoid a compiler warning

into  mysql.com:/data0/mysqldev/users/tomas/mysql-5.0-maint

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

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/mar07/stage2/50

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/mar07/stage2/50

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into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/mrg0306/50