Adding comments to test cases.

In certain situations, a scan of the table will return the error
code HA_ERR_RECORD_DELETED, and this error code is not 
correctly caught in the Rows_log_event::find_row() function, which
causes an error to be returned for this case.

This patch fixes the problem by adding code to either ignore the
record and continuing with the next one, the the event of a table
scan, or change the error code to HA_ERR_KEY_NOT_FOUND, in the event
that a key lookup is attempted.

           derived table cause crash

When a multi-UPDATE command fails to lock some table, and
subsequently succeeds, the tables need to be reopened if
they were altered. But the reopening procedure failed for
derived tables.

Extra cleanup has been added.

Fixed a compilation warning

upgrade from <=5.0.46 to >=5.0.48

Problem: 'check table .. for upgrade' doesn't detect 
incompatible collation changes made in 5.0.48.

Fix: check for incompatible collation changes.

The failure was caused by executing a CREATE-SELECT statement that creates a
table in another database than the current one. In row-based logging, the
CREATE statement was written to the binary log without the database, hence
creating the table in the wrong database, causing the following inserts to
fail since the table didn't exist in the given database.

Fixed the bug by adding a parameter to store_create_info() that will make
the function print the database name before the table name and used that
in the calls that write the CREATE statement to the binary log. The database
name is only printed if it is different than the currently selected database.

The output of SHOW CREATE TABLE has not changed and is still printed without
the database name.

disabled a randomly failing test and opened a bug report

InnoDB Plugin locks table

This is a pre fix update that does the change to the handler api.

This is done since there are already changes in this version,
so the real fix does not need to change the api.

          ``FLUSH TABLES WITH READ LOCK''

Concurrent execution of 1) multitable update with a
NATURAL/USING join and 2) a such query as "FLUSH TABLES
WITH READ LOCK" or "ALTER TABLE" of updating table led
to a server crash.


The mysql_multi_update_prepare() function call is optimized
to lock updating tables only, so it postpones locking to
the last, and if locking fails, it does cleanup of modified
syntax structures and repeats a query analysis.  However,
that cleanup procedure was incomplete for NATURAL/USING join
syntax data: 1) some Field_item items pointed into freed
table structures, and 2) the TABLE_LIST::join_columns fields
was not reset.

Major change:
  short-living Field *Natural_join_column::table_field has
  been replaced with long-living Item*.

ha_statistic_increment for rpl_temporary

Problem: in some cases master send a special event to reconnecting
slave to keep slave's temporary tables (see #17284) and they still 
have references to the "old" SQL slave thread and use them to access
thread's data.

Fix: set temporary tables thread references to the actual SQL slave
thread in such cases.

so that if the substitution contains single-quotes, the program will fail.

Adds --general-log-file, --slow-query-log-file command-
line options to match system variables of the same names.

Deprecates --log, --log-slow-queries command-line option
and log, log_slow_queries system-variables for v7.0; they
are superseded by general_log/general_log_file and
slow_query_log/slow_query_log_file, respectively.

"Trigger fired multiple times leads to gaps in auto_increment sequence".
The bug was that if a trigger fired multiple times inside a top
statement (for example top-statement is a multi-row INSERT,
and trigger is ON INSERT), and that trigger inserted into an auto_increment
column, then gaps could be observed in the auto_increment sequence,
even if there were no other users of the database (no concurrency).
It was wrong usage of THD::auto_inc_intervals_in_cur_stmt_for_binlog.
Note that the fix changes "class handler", I'll tell the Storage Engine API team.

MyISAM blocks index usage for bulk insert into zero-records tables.
See ha_myisam::start_bulk_insert() lines from
...
    if (file->state->records == 0 ...
...

That causes problems for partition engine when some partitions have records some not
as the engine uses same access method for all partitions.

Now partition engine doesn't call index_first/index_last
for empty tables.

per-file comments:
  mysql-test/r/partition.result
        Bug#38005 Partitions: error with insert select.
        test result

  mysql-test/t/partition.test
        Bug#38005 Partitions: error with insert select.
        test case

  sql/ha_partition.cc
        Bug#38005 Partitions: error with insert select.
        ha_engine::index_first and
        ha_engine::index_last not called for empty tables.