A corrupted compressed table could crash the server and
myisamchk.

The data file of an uncompressed table contains just the records.
There is no header in the data file.

However the data file of a compressed table has a header.
The header describes how the table was compressed. This
information is necessary to extract the records from the
compressed data file.

Part of the compressed data file header are the [de]code tables.
They are numeric representations of the Huffman trees used for
coding and decoding. A Huffman tree is a binary tree. Every
node has two childs. A child can be a leaf or a branch. Leaves
contain the decoded value. Branches point to another tree node.

Since the [de]code table is represented as an array of childs,
the branches need to point at a child within the same array.
The corruption of the compressed data file from the bug report
was a couple of branches that pointed outside their array.
This condition had not been correctly checked.

I added some checks for the pointers in the decode tables.
This type of corruption will no longer crash the server or
myisamchk.

No test case. A corrupted compressed table is required.

into  chilla.local:/home/mydev/mysql-4.1-bug8283-one

OPTIMIZE TABLE with myisam_repair_threads > 1 performs a non-quick 
parallel repair. This means that it does not only rebuild all 
indexes, but also the data file.

Non-quick parallel repair works so that there is one thread per 
index. The first of the threads rebuilds also the new data file.

The problem was that all threads shared the read io cache on the
old data file. If there were holes (deleted records) in the table,
the first thread skipped them, writing only contiguous, non-deleted
records to the new data file. Then it built the new index so that
its entries pointed to the correct record positions. But the other
threads didn't know the new record positions, but put the positions
from the old data file into the index.

The new design is so that there is a shared io cache which is filled
by the first thread (the data file writer) with the new contiguous
records and read by the other threads. Now they know the new record
positions.

Another problem was that for the parallel repair of compressed
tables a common bit_buff and rec_buff was used. I changed it so
that thread specific buffers are used for parallel repair.

A similar problem existed for checksum calculation. I made this
multi-thread safe too.

into  mysql.com:/home/svoj/devel/mysql/BUG22937/mysql-4.1-engines

This is addition to fix for bug21617. Valgrind reports an error when
opening merge table that has underlying tables with less indexes than
in a merge table itself.

Copy at most min(file->keys, table->key_parts) elements from rec_per_key array.
This fixes problems when merge table and subtables have different number of keys.

into  mysql.com:/home/svoj/devel/mysql/BUG21381/mysql-4.1-engines

Though this is not storage engine specific problem, I was able to
repeat this problem with BDB and NDB engines only. That was the
reason to add a test case into ndb_update.test. As a result
different bad things could happen.

BDB has removed duplicate rows which is not expected.
NDB returns an error.

For multi table update notify storage engine about UPDATE IGNORE
as it is done in single table UPDATE.

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-4.1-engines

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-4.1-engines

into  chilla.local:/home/mydev/mysql-4.0-bug20719

into  chilla.local:/home/mydev/mysql-4.1-bug22384

into  chilla.local:/home/mydev/mysql-4.1-bug22384

into  mysql.com:/home/svoj/devel/mysql/BUG21617/mysql-4.1-engines

Crash may happen when selecting from a merge table that has underlying
tables with less indexes than in a merge table itself.

If number of keys in merge table is not bigger than requested key number,
return error.

into  chilla.local:/home/mydev/mysql-4.1-bug20719-m

Deletes on a big index could crash the index when it needs to
shrink.

Put a forgotten negation operator in.

No test case. It is too big for the test suite. And it does not
work with 4.0, only with higher versions. It is attached to the
bug report.

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-4.1-opt

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-4.1-engines

into  chilla.local:/home/mydev/mysql-4.0-bug20719

After merge fix.

into  chilla.local:/home/mydev/mysql-4.1-bug20719-m

into  mysql.com:/home/hf/work/mysql-4.1.15428

an ALL/ANY quantified subquery in HAVING.
The Item::split_sum_func2 method should not create Item_ref
for objects of any class derived from Item_subselect.

into  mysql.com:/home/hf/work/mysql-4.1.15428

into  mysql.com:/home/hf/work/mysql-4.1.15428

  Filter out plain -O and Sun C/C++ style optimization flags, -xO<level>
  Filter out icc specific options from cflags/libs(_r)

into  chilla.local:/home/mydev/mysql-4.1-bug14400-monty

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-4.1-merge

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-4.1-merge

            "concurrent insert"
After merge fix.

into  chilla.local:/home/mydev/mysql-4.0-bug14400

into  chilla.local:/home/mydev/mysql-4.0-bug14400

Any default value for a enum fields over UCS2 charsets was corrupted
when we put it into the frm file, as it had been overwritten by its
HEX representation.
To fix it now we save a copy of structure that represents the enum
type and when putting the default values we use this copy. 

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-4.1-merge