Added open log file with FILE_SHARE_DELETE flag on Windows.

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.

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.

This is a performance improvement fix.

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

feature

The test for bug no 50939 was put in range.test which isn't such a good idea
since it requires partitioning. Fixed by moving the test case to
partitioning_range.test.

Updated the README file.

                        
After BUG#36649, warnings for sub-statements are cleared when a 
new sub-statement is started. This is problematic since it suppresses
warnings for unsafe statements in some cases. It is important that we
always give a warning to the client, because the user needs to know
when there is a risk that the slave goes out of sync.
                        
We fixed the problem by generating warning messages for unsafe statements
while returning from a stored procedure, function, trigger or while
executing a top level statement.
                        
We also started checking unsafeness when both performance and log tables are
used. This is necessary after the performance schema which does a distinction
between performance and log tables.

Fix by adding "DEPENDS gen_lex_hash" to ADD_CUSTOM_COMMAND(),
so it regenerates lex_hash.h whenever gen_lex_lash changes.

Also, make sql dependent on GenServerSource to avoid concurrent 
generation of lex_hash.h (once for sql , and in parallel for embedded)