Item_default_value::arg can be NULL so walk() should take it into consideration.

(mainly by backporting 5.5. changes)

mysql-test/suite/maria/t/distinct.test:
  Remove the test that requires SSL. One test case for a bug is enough.
sql/scheduler.cc:
  make it the same as in 5.5
storage/innodb_plugin/row/row0mysql.c:
  make it the same as in 5.5
storage/innodb_plugin/row/row0sel.c:
  make it the same as in 5.5
storage/xtradb/row/row0mysql.c:
  make it the same as in 5.5
storage/xtradb/row/row0sel.c:
  make it the same as in 5.5

fix the NAME_CONST check to only allow literals, negated literals, and literals with
the explicit collation.

THD::thd->activate_stmt_arena_if_needed() should be used to temporary activating statement arena instead of direct usage of THD::set_n_backup_active_arena() because possible such scenario:
  1) func1 saves current arena and activates copy1 of statement arena
  2) func2 saves copy1 of statement arena setup by func1 and activates copy2
  3) some changes made for copy 2
  4) func2 stores changed copy2 back to statenet arena and activates copy1
  5) func1 store unchanged copy1 back to statemnt arena (rewrite changed copy 2 so changes become lost) and activates arena which was before.

Fix ha_myisammrg::update_create_info() to do what ha_myisammrg::append_create_info() does -
take sub-table names from TABLE_LIST, not reverse engineer tablefile names.

Backport praveenkumar.hulakund@oracle.com-20120127081643-u7dxy23i8yyqarm7 from mysql-5.6

mysql_tzinfo_to_sql is not compiled under Windows in the pre-5.5 versions.
Do not set the MYSQL_TZINFO_TO_SQL variable in the version prior to 5.5
under Windows.

Allow only one level of symlink recursion in mysql_tzdata_to_sql,
to avoid infinite loops.

The loop in the binary search in remove_status_vars() was
incorrectly implemented and could continue infinitely in some cases.
Rewrote the binary search code.

This a an old legacy performance bug.
When a very selective range scan existed for the second table in a join,
and, at the same time, there was another range condition depending on the
fields of the first table, the optimizer chose a plan with
'Range checked for each record'. This plan was extremely inefficient in
comparison with the regular selective range scan.
As a matter of fact the range scan chosen for each record was the same as
that selective range scan. 

Changed the test case for bug 24776 to preserve the old output for explain.
 

MDEV-4823: Server crashes in Item_func_not::fix_fields on creating a table with a virtual column using NOT

fix_field() call protocol was brocken (zero pointer passed as link to item which is possible only if you are sure that there can not be Items which transforms).

   not_enough_points() introduced to check if the spatial object is incorrect.

MDEV-4409 - Fix deadlock in MySQL key cache code, that can happen if there is a key cache resize running in parallel with an update.

If there is a key cache resize,a  thread writing to key cache, will pause waiting  until resize finishes. However this thread is won't be woken, because resize does not  signaling waiters anymore. This is a regression introduced in WL#86(segmented MyISAM key cache)
The fix is to unconditionally release  threads waiting on resize_queue when resize  finishes, as in pre-WL#86 code.

modified:
  mysql-test/suite/plugins/r/fulltext_plugin.result
  mysql-test/suite/plugins/t/fulltext_plugin.test
  plugin/fulltext/plugin_example.c
  sql/sql_show.cc
pending merges:
  Sergei Golubchik 2013-07-06 Bug #69682 - mysqld crashes after uninstall ...
    Sergei Golubchik 2013-05-24 MDEV-4575 MySQL client doesn't strip off...

extend 5.1 client library to read 4 byte capabilities from the first handshake packet.
two higher bytes are always zeros for 5.1 servers.

MDEV-4280: Assertion `empty_size == empty_size_on_page' failure in ma_blockrec.c or ER_NOT_KEYFILE on query with DISTINCT and GROUP BY
This could happen when using Aria for internal temporary files (default case) and using DISTINCT.
_ma_scan_restore_block_record() didn't work correctly if there was rows inserted, updated or deleted on the handler
between calls to _ma_scan_remember_block_record() and _ma_scan_restore_block_record().
The effect was that some DISTINCT queries that used remove_dup_with_compare() could fail.

.bzrignore:
  Ignore sql_yacc.hh
mysql-test/suite/maria/r/distinct.result:
  Test case for MDEV-4280
mysql-test/suite/maria/t/distinct.test:
  Test case for MDEV-4280
mysql-test/t/mysql.test:
  Fixed test suite (we could get error -1 in some cases)
sql/sql_select.cc:
  Break loop if restart_rnd_next() gives an error
storage/maria/ha_maria.cc:
  scan_restore_pos() can return disk fault error.
storage/maria/ma_blockrec.c:
  _ma_scan_remember_block_record() did incorrectly update scan.dir instead of scan_save.dir .
  _ma_scan_restore_block_record() didn't work correctly if there was rows inserted,updated or deleted on the handler
  between calls to _ma_scan_remember_block_record() and _ma_scan_restore_block_record().
  Fixed by adding counters for row changes and reading the current scan page if changes had been made.
storage/maria/ma_blockrec.h:
  scan_restore_pos() can return disk fault error.
storage/maria/ma_delete.c:
  Increment row_changes
storage/maria/ma_scan.c:
  scan_restore_pos() can return disk fault error.
storage/maria/ma_update.c:
  Increment row_changes
storage/maria/ma_write.c:
  Increment row_changes
storage/maria/maria_def.h:
  scan_restore_pos() can return disk fault error.

avoid divison by zero