== MYSQL_TYPE_LONGLONG

A MIN/MAX() function with a subquery as its argument could lead
to a debug assertion on debug builds or wrong data on release
ones.

The problem was a combination of the following factors:

- Item_sum_hybrid::fix_fields() might use the argument
(args[0]) to calculate 'hybrid_field_type' which was later used
to decide how the data should be sent to the client.

- Item_sum::make_field() might use the argument again to
calculate the field's type when sending result set metadata to
the client.

- The argument could be changed in between these two calls via
  Item::set_arg() leading to inconsistent metadata being
  reported.

Here is what was happening for the bug's test case:

1. Item_sum_hybrid::fix_fields() calculates hybrid_field_type
as MYSQL_TYPE_LONGLONG based on args[0] which is an
Item::SUBSELECT_ITEM at that time.

2. A temporary table is created to execute the
query. create_tmp_field_from_item() creates a Field_long object
according to the subselect's max_length.

3. The subselect item in Item_sum_hybrid is replaced by the
Item_field object referencing the newly created Field_long.

4. Item_sum::make_field() rightfully returns the
MYSQL_TYPE_LONG type when calculating the result set metadata.

5. When sending the actual data, Item::send() relies on the
virtual field_type() function which in our case returns
previously calculated hybrid_field_type == MYSQL_TYPE_LONGLONG.

It looks like the only solution is to never refer to the
argument's metadata after the result metadata has been
calculated in fix_fields(), since the argument itself may be
different by then. In this sense, Item_sum::make_field() should
never be used, because it may rely on the argument's metadata
and is only called after fix_fields(). The "default"
implementation in Item::make_field() should be used instead as
it relies only on field_type(), but not on the argument's type.

Fixed by removing Item_sum::make_field() so that the superclass
implementation Item::make_field() is always used.

mysql-test/r/func_group.result:
  Added a test case for bug #54465.
mysql-test/t/func_group.test:
  Added a test case for bug #54465.
sql/item_sum.cc:
  Removed Item_sum::make_field() so that the superclass
  implementation Item::make_field() is always used.
sql/item_sum.h:
  Removed Item_sum::make_field() so that the superclass
  implementation Item::make_field() is always used.

Free memory allocated by the server for all plugins,
with or without deinit() method.

After fix for bug 39653 the shortest available secondary index was used for
full table scan. Primary clustered key was used only if no secondary index
can be used. However, when chosen secondary index includes all fields of the
table being scanned it's better to use primary index since the amount of
data to scan is the same but the primary index is clustered.
Now the find_shortest_key function takes this into account.


mysql-test/suite/innodb/r/innodb_mysql.result:
  Added a test case for the bug#55656.
mysql-test/suite/innodb/t/innodb_mysql.test:
  Added a test case for the bug#55656.
sql/sql_select.cc:
  Bug #55656: mysqldump can be slower after bug #39653 fix.
  The find_shortest_key function now prefers clustered primary key
  if found secondary key includes all fields of the table.

Added open log file with FILE_SHARE_DELETE flag on Windows.

sql/log.cc:
  added reopen_fstreams();
  modified redirect_std_streams(): call to sequence of freopen()
  replaced to reopen_fstreams();
  modified flush_error_log(): removed file rename for flushed
  error log file.
sql/mysqld.cc:
  modified main() and init_server_components(): do open log error file
  over call to reopen_fstreams().

Added code resulted in strange linking problem for embedded on Windows
Avoided by not doing this for embedded mode
It's irrelevant for embedded server anyway, --protocol will be ignored

Queries involving predicates of the form "const NOT BETWEEN
not_indexed_column AND indexed_column" could return wrong data
due to incorrect handling by the range optimizer.

For "c NOT BETWEEN f1 AND f2" predicates, get_mm_tree()
produces a disjunction of the SEL_ARG trees for "f1 > c" and
"f2 < c". If one of the trees is empty (i.e. one of the
arguments is not sargable) the resulting tree should be empty
as well, since the whole expression in this case is not
sargable.

The above logic is implemented in get_mm_tree() as follows. The
initial state of the resulting tree is NULL (aka empty). We
then iterate through arguments and compute the corresponding
SEL_ARG tree (either "f1 > c" or "f2 < c"). If the resulting
tree is NULL, it is simply replaced by the generated
tree. Otherwise it is replaced by a disjunction of itself and
the generated tree. The obvious flaw in this implementation is
that if the first argument is not sargable and thus produces a
NULL tree, the resulting tree will simply be replaced by the
tree for the second argument. As a result, "c NOT BETWEEN f1
AND f2" will end up as just "f2 < c".

Fixed by adding a check so that when the first argument
produces an empty tree for the NOT BETWEEN case, the loop is
aborted with an empty tree as a result. The whole idea of using
a loop for 2 arguments does not make much sense, but it was
probably used to avoid code duplication for several BETWEEN
variants.

So null merge.

        'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour
BUG#55474, BUG#55499, BUG#55598, BUG#55616 and BUG#55777 are fixed
in this patch too.

This is the 5.1 part.
It implements:
- if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
  and INSERT ... SELECT

- Insert nothing and binlog nothing on master if the existing object
  is a view. It only generates a warning that table already exists.


mysql-test/r/trigger.result:
  Ather this patch, 'CREATE TABLE IF NOT EXISTS ... SELECT' will not
  insert anything if the creating table already exists and is a view.
sql/sql_class.h:
  Declare virtual function write_to_binlog() for select_insert.
  It's used to binlog 'create select'
sql/sql_insert.cc:
  Implement write_to_binlog();
  Use write_to_binlog() instead of binlog_query() to binlog the statement.
  if the table exists, binlog two events: CREATE TABLE IF NOT EXISTS
  and INSERT ... SELECT
sql/sql_lex.h:
  Declare create_select_start_with_brace and create_select_pos.
  They are helpful for binlogging 'create select'
sql/sql_parse.cc:
  Do nothing on master if the existing object is a view.
sql/sql_yacc.yy:
  Record the relative postion of 'SELECT' in the 'CREATE ...SELECT' statement.
  Record whether there is a '(' before the 'SELECT' clause.

variable assignments

The assert() that is firing is checking if expressions that can't be
null return a NULL when evaluated.
MAKEDATE() function can return NULL if the second argument is 
less then or equal to 0. Thus its nullability depends not only on 
the nullability of its arguments but also on their values.
Fixed by (overoptimistically) setting MAKEDATE() to be nullable 
despite the nullability of its arguments.
Test added.
Had to update one test result to reflect the metadata change.

The server was not checking for errors generated during
the execution of Item::val_xxx() methods when copying
data to the group, order, or distinct temp table's row.
Fixed by extending the copy_funcs() to return an error
code and by checking for that error code on the places
copy_funcs() is called. 
Test case added.

Fixing copyright text.

it couldn't parse the --ssl option.

client/mysql_upgrade.c:
  mysql_upgrade parses its options and passes some of them to the underlying
  tools (mysqlcheck etc). To do this passdown, it reconstructs a
  command-line-suitable text from the my_option object (which
  contains the option's name and option's value). For options
  which expect no parameter, it just had to use the option's name;
  for other options, it had to concatenate the option's name,
  a "=" symbol, and the option's value; it had code to handle
  this latter case, but only for GET_STR options (options taking a
  string as value). But since the work on WL 4738, the --ssl
  option, a GET_BOOL, which used to have no parameter (NO_ARG), can
  now have one (OPT_ARG), so with --ssl we came to the "default"
  label, error. Fixed by constructing the command-line-suitable
  representation for GET_BOOL too. For --ssl it will produce
  --ssl=1 ; for --ssl=0, it will produce --ssl=0.
mysql-test/include/mysql_upgrade_preparation.inc:
  handles requirements of tests which use mysql_upgrade
mysql-test/r/mysql_upgrade_ssl.result:
  result; without the code fix we would get "internal error".
mysql-test/t/mysql_upgrade.test:
  This test has requirements before running; moved them
  to an include file in order to share with mysql_upgrade_ssl.
mysql-test/t/mysql_upgrade_ssl.test:
  test for bug. Couldn't go into mysql_upgrade.test as this new test requires
  SSL support. --force is needed, in case mysql_upgrade.test run before
  (in which case mysql_upgrade_ssl would say that upgrade has already been
  done); --force forces the upgrade in all cases.

This is a performance improvement fix.

Removed the "volatile" property of PFS_events_waits::m_wait_class.
Simplified the code accordingly.