This was needed as the old code caused us to have LOTS of duplicate
hash values when used by optimizer.

include/m_ctype.h:
  Made my_hash_sort_bin() exernal
storage/maria/ma_unique.c:
  Better hash for packed numeric data for unique handling.
  This was needed as the old code caused us to have LOTS
  of duplicate hash values when used by optimizer.

mysys/my_handler.c:
  Fixed typo

Made sure that the optimal fields are used by TABLE_REF objects
when building index access keys to joined tables.
Fixed a bug in the template function that sorts the elements of
a list using the bubble sort algorithm. The bug caused poor
performance of the function. Also added an optimization that
skips comparison with the most heavy elements that has been 
already properly placed in the list.
Made the comparison of the fields belonging to the same Item_equal
more granular: fields belonging to the same table are also ordered
according to some rules.

An assertion failure was triggered for a 6-way join query that used two
join buffers.
The failure happened because every call of JOIN_CACHE::join_matching_records
saved and restored status of all tables that were accessed before the table
join_tab. It must do it only for those of them that follow the last table 
using a join buffer.

- Backport testcases
- We have a different fix because we've fixed part of the problem as part of fix for LPBUG#602574.

Backport testcase: BUG#45863 "Assertion failed: (fixed == 0), function fix_fields(), file item.cc, line 4448"
(The fix was backported with subquery code backport)

3150 Olav Sandstaa     2010-05-07
Test cases for the following "ICP for InnoDB" bugs:

Bug#40992 InnoDB: Crash when engine_condition_pushdown is on
Bug#35080 Innodb crash at mem_block_get_len line 72
Bug#41996 multi-table delete crashes server (InnoDB table)
Bug#43448 Server crashes on multi table delete with Innodb

All these bugs are duplicates of either one or both of Bug 43360 or 36981.

(backporting of olav@sun.com-20100226091930-qxvakxmcp6463t5w)

Test case backport for: Bug#42580 - Innodb's ORDER BY ..LIMIT returns no rows for null-safe operator <=> NULL

(the bug itself was fixed during the subquery code backport)

3723 oystein.grovlen@sun.com   2009-11-23
Bug#46548 (addendum)
Remove KEY::extra_length.  It is not in use.

Bug #45092: join buffer contains two blob columns one of which is used in the key employed to access the joined table

Date: Mon, 01 Nov 2010 15:15:25 -0000
3272 Roy Lyseng        2010-11-01
Bug#52068: Optimizer generates invalid semijoin materialization plan

When MaterializeScan semijoin strategy was used and there were one
or more outer dependent tables before the semijoin tables, the scan
over the materialized table was not properly reset for each row of
the prefix outer tables.

Example: suppose we have a join order:

  ot1 SJ-Mat-Scan(it2 it3)  ot4

Notice that this is called a MaterializeScan, even though there is an
outer table ahead of the materialized tables. Usually a MaterializeScan
has the outer tables after the materialized table, but this is
a special (but legal) case with outer dependent tables both before and
after the materialized table.

For each qualifying row from ot1, a new scan over the materialized
table must be set up. The code failed to do that, so all scans after
the first one returned zero rows from the materialized table.

- Cause: handler::in_range_check_pushed_down was not reset when a 
  command would call handler->idx_cond_push() without later calling
  handler->index_end().
- Fix: reset the variable in handler->reset(), too (like we do with other
  Index Condition Pushdown members).

When stored in a key buffer any varchar field has a length prefix
that always takes 2 bytes.

Added a test case for bug #695442 - a duplicate of bug 694092.

The bug was the result of a bad merge maria-5.2-wl21 -> 5.3.

One of the hash functions employed by the BNLH join algorithm
calculates the the value of hash index for key value utilizing
every byte of the key buffer. To make this calculation valid
one has to ensure that for any key value unused bytes of the 
buffer are filled with with a certain filler. We choose 0 as
a filler for these bytes.

Added an optional boolean parameter with_zerofill to the function
key_copy. If the value of the parameter is TRUE all unused bytes
of the key buffer is filled with 0. 

- Backport the testcase (the fix itself was included with the subquery optimizations backport)

In some cases the function make_cond_for_index() was mistaken
when detecting index only pushdown conditions for a table: 
a pushdown condition that was not index only could be marked
as such.
It happened because the procedure erroneously used the markers
for index only conditions that remained from the calls of
this function that extracted the index conditions for other 
tables.
Fixed by erasing index only markers as soon as they are need
anymore.

Lifted the limitation that hash join could not be used over 
varchar fields with non-binary collation.