MDEV-7672: Crash creating an InnoDB table with foreign keys

Analysis: after a red-black-tree lookup we use node withouth
checking did lookup succeed or not. This lead to situation
where NULL-pointer was used.

Fix: Add additional check that found node from red-back-tree
is valid.

MDEV-7673: CREATE TABLE SELECT fails on Galera cluster

Enable execution of CREATE TABLE SELECT in total order isolation. Added
a test case.

Contributed by : Andrew W Elble

MDEV-6323: ‘explain_node’ may be used uninitialized in this function

- Remove the compiler warning, add assert statements.
- make select_describe() not call mysql_explain_union() for
  views that were "merged for INSERT".

Merge remote-tracking branch 'origin/10.0' into 10.0

MDEV-7419 Function cli_safe_read not exported

Start the client API for low-level protocol access:
* unsigned long mysql_net_read_packet(MYSQL *mysql);
* unsigned long mysql_net_field_length(unsigned char **packet);

MDEV-5719: Wrong result with GROUP BY and LEFT OUTER JOIN

Merged revision 5224 from mysql-5.6 and added a test case.
..
revno: 5224
committer: Sergey Glukhov <sergey.glukhov@oracle.com>
branch nick: mysql-5.6
timestamp: Wed 2013-06-19 14:24:08 +0400
message:
    Bug#16620047 INCORRECT QUERY RESULT (AFTER SERVER UPGRADE)

merge

my_alloc.c

- Changed 0x%lx -> %p
array.c:
- Static (preallocated) buffer can now be anywhere
my_sys.h
- Define MY_INIT_BUFFER_USED
sql_delete.cc & sql_lex.cc
- Use memroot when allocating classes (avoids call to current_thd)
sql_explain.h:
- Use preallocated buffers
sql_explain.cc:
- Use preallocated buffers and memroot
sql_select.cc:
- Use multi_alloc_root() instead of many alloc_root()
- Update calls to Explain

5.5 merge

Merge branch 'bb-10.1-merge' into 10.1