create_sort_index() function overwrites original JOIN_TAB::type field.
At re-execution of subquery overwritten JOIN_TAB::type(JT_ALL) is
used instead of JT_FT. It misleads test_if_skip_sort_order() and
the function tries to find suitable key for the order that should
not be allowed for FULLTEXT(JT_FT) table.
The fix is to restore JOIN_TAB strucures for subselect on re-execution
for EXPLAIN.
Additional fix:
Update TABLE::maybe_null field which
affects list_contains_unique_index() behaviour as it
could have the value(maybe_null==TRUE) based on the
assumption that this join is outer
(see setup_table_map() func).

Subquery executes twice, at top level JOIN::optimize and ::execute stages.
At first execution create_sort_index() function is called and
FT_SELECT object is created and destroyed. HANDLER::ft_handler is cleaned up
in the object destructor and at second execution FT_SELECT::get_next() method
returns error.
The fix is to reinit HANDLER::ft_handler field before re-execution of subquery.

Where realpath(3) is used in Linux, mf_load_path is
used for Windows. This function doesn't however
correspond to the functionality of realpath.
This patch attempts to do better by using 
the Windows function GetFullPathName() instead.

Problem: some call of INET_NTOA() function may lead 
to a crash due to missing its character set initialization.

Fix: explicitly set the character set.

Problem: if multibyte and binary string arguments passed to 
RPAD(), LPAD() or INSERT() functions, they might return 
wrong results or even lead to a server crash due to missed
character set convertion.

Fix: perform the convertion if necessary.

with concurrent lock/unlock tables

Approved by Marko

row_create_table_for_mysql(): When the table creation fails,
free the dict_table_t object.

row_create_table_for_mysql(): When the table creation fails,
free the dict_table_t object.

No mysql-test case. Tested by creating a table, removing a *.frm file and
attempting to create the table again. Code coverage tested by
instrumentation. Tested with Valgrind.

Print an error message to stderr an get rid of the assertion.

Approved by: Jimmy Yang (over IM)

linked with foreign keys at once" from mysql-5.1-security to
mysql-5.5-security again.

rb://391 approved by Heikki

rb://477 approved by Marko