Fix formatting issues in README file.

EXCEPTIONS-CLIENT from all the places.

See bug #58416.

In case of low memory sort buffer QUICK_INDEX_MERGE_SELECT creates
temporary file where is stores row ids which meet QUICK_SELECT ranges
except of clustered pk range, clustered range is processed separately.
In init_read_record we check if temporary file is used and choose
appropriate record access method. It does not take into account that
temporary file contains partial result in case of QUICK_INDEX_MERGE_SELECT
with clustered pk range.
The fix is always to use rr_quick if QUICK_INDEX_MERGE_SELECT
with clustered pk range is used.

5.0-security --> 5.1-security

> revision-id: alexey.kopytov@sun.com-20100824103548-ikm79qlfrvggyj9h
> parent: sunny.bains@oracle.com-20100816001222-xqc447tr6jwh8c53
> committer: Alexey Kopytov <Alexey.Kopytov@Sun.com>
> branch nick: 5.1-security
> timestamp: Tue 2010-08-24 14:35:48 +0400
> message:
>   Bug #55568: user variable assignments crash server when used
>               within query
>   
>   The server could crash after materializing a derived table
>   which requires a temporary table for grouping.
>   
>   When destroying the temporary table used to execute a query for
>   a derived table, JOIN::destroy() did not clean up Item_fields
>   pointing to fields in the temporary table. This led to
>   dereferencing a dangling pointer when printing out the items
>   tree later in the outer SELECT.
>   
>   The solution is an addendum to the patch for bug37362: in
>   addition to cleaning up items in tmp_all_fields3, do the same
>   for items in tmp_all_fields1, since now we have an example
>   where this is necessary.

and related small fixes.

Although ICC identifies itself as GCC, even in version numbers,
it does not support the stpcpy built-in.

 options/settings
 
 1. Changed the default value for socket on Windows to the windows
 default
 2. Removed hard-coded trailing slashes from innodb_data_home_dir
 and innodb_log_group_name_dir.
 3. Added extra backslashes to the innodb directory example
 4. Made the tempdir platform "dependent"
 5. Fixed the comments in the .ini files
 6. Removed the tmpdir from the templates and the scripts

Problem: crash in Item_float constructor on DBUG_ASSERT due
to not null-terminated string parameter.

Fix: making Item_float::Item_float non-null-termintated parameter safe:
- Using temporary buffer when generating error

modified:
  @ mysql-test/r/xml.result
  @ mysql-test/t/xml.test
  @ sql/item.cc

ESCAPE argument might be empty string. It leads
to server crash under some circumstances.
The fix:
-added check if ESCAPE argument result is not empty string

Evaluation would start with the space and thus ignore the $
Added while() to skip past white space

Use __builtin_stpcpy only if the system supports stpcpy.
This is necessary as in some cases a call to stpcpy will
be emitted if the built-in can not optimized.

for --list_files in mysqltest.

Results from query is sent for evaluation
Break recursion by asking for ` to be ignored

Problem: When GET_FORMAT() is called two times from the upper
level function (e.g. LEAST in the bug report), on the second
call "res= args[0]->val_str(...)" and str point to the same
String object.

1. Fix: changing the order from
- get val_str into tmp_value then convert to str
to
- get val_str into str then convert to tmp_value

The new order is more correct: the purpose of "str" parameter
is exactly to call val_str() for arguments.
The purpose of String class members (like tmp_value) is to do further
actions on the result.
Doing it in the other way around give unexpected surprises.

2. Using str_value instead of str to do padding, for the same reason.

thr_local_create(): Initialize local->slot_no to ULINT_UNDEFINED.
thr_local_validate(): Allow local->slot_no to be ULINT_UNDEFINED.

Also delete dict_update_statistics() and rename dict_update_statistics_low()
to dict_update_statistics() because the only thing that distinguished those
two functions was the removed parameter.

Bug#57820 extractvalue crashes

Problem: ExtractValue and Replace crashed in some cases
due to invalid handling of empty and NULL arguments.

Per file comments:

  @mysql-test/r/ctype_ujis.result
  @mysql-test/r/xml.result
  @mysql-test/t/ctype_ujis.test
  @mysql-test/t/xml.test
  Adding tests

  @sql/item_strfunc.cc
  Make sure Item_func_replace::val_str safely handles empty strings.

  @sql/item_xmlfunc.cc
  set null_value if nodeset_func returned NULL,
  which is possible when the second argument is an
  unset user variable.

thr_local_validate(), i_s_locks_row_validate(): New validate
functions, used in UNIV_DEBUG code for checking the state of internal
memory structures.

to the error log

rb://513 approved by Sunny Bains