Original revid: alexey.kopytov@sun.com-20100723115254-jjwmhq97b9wl932l

 > Bug #54476: crash when group_concat and 'with rollup' in
 >                      prepared statements
 >
 > Using GROUP_CONCAT() together with the WITH ROLLUP modifier
 > could crash the server.
 >
 > The reason was a combination of several facts:
 >
 > 1. The Item_func_group_concat class stores pointers to ORDER
 > objects representing the columns in the ORDER BY clause of
 > GROUP_CONCAT().
 >
 > 2. find_order_in_list() called from
 > Item_func_group_concat::setup() modifies the ORDER objects so
 > that their 'item' member points to the arguments list
 > allocated in the Item_func_group_concat constructor.
 >
 > 3. In some cases (e.g. in JOIN::rollup_make_fields) a copy of
 > the original Item_func_group_concat object could be created by
 > using the Item_func_group_concat::Item_func_group_concat(THD
 > *thd, Item_func_group_concat *item) copy constructor. The
 > latter essentially creates a shallow copy of the source
 > object. Memory for the arguments array is allocated on
 > thd->mem_root, but the pointers for arguments and ORDER are
 > copied verbatim.
 >
 > What happens in the test case is that when executing the query
 > for the first time, after a copy of the original
 > Item_func_group_concat object has been created by
 > JOIN::rollup_make_fields(), find_order_in_list() is called for
 > this new object. It then resolves ORDER BY by modifying the
 > ORDER objects so that they point to elements of the arguments
 > array which is local to the cloned object. When thd->mem_root
 > is freed upon completing the execution, pointers in the ORDER
 > objects become invalid. Those ORDER objects, however, are also
 > shared with the original Item_func_group_concat object which is
 > preserved between executions of a prepared statement. So the
 > first call to find_order_in_list() for the original object on
 > the second execution tries to dereference an invalid pointer.
 >
 > The solution is to create copies of the ORDER objects when
 > copying Item_func_group_concat to not leave any stale pointers
 > in other instances with different lifecycles.

Automerging mysql-5.1-bugteam into mysql-5.5-bugteam.

Autmoerging into latest mysql-5.1-bugteam.

Addressing review comments.

Bug#57913 large negative number to string conversion functions crash
String object which is used as result container of the item
has uninitialized 'str_charset' field. This object
might be used later to preform some internal operations
and str_charset field is involved in these operations.
It leads to crash.
The fix is to intialize str_charset in my_decimal2string() func.

Backport from 5.5. OK from Anitha G. to push to 5.1.

Removed floor(float_col) tests, enabled floor(decimal_col) tests

--Bug#52157 various crashes and assertions with multi-table update, stored function
--Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb
--Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846
--Bug#57352 valgrind warnings when creating view
--Recently discovered problem when a nested materialized derived table is used
  before being populated and it leads to incorrect result

We have several modes when we should disable subquery evaluation.
The reasons for disabling are different. It could be
uselessness of the evaluation as in case of 'CREATE VIEW'
or 'PREPARE stmt', or we should disable subquery evaluation
if tables are not locked yet as it happens in bug#54475, or
too early evaluation of subqueries can lead to wrong result
as it happened in Bug#19077.
Main problem is that if subquery items are treated as const
they are evaluated in ::fix_fields(), ::fix_length_and_dec()
of the parental items as a lot of these methods have
Item::val_...() calls inside.
We have to make subqueries non-const to prevent unnecessary
subquery evaluation. At the moment we have different methods
for this. Here is a list of these modes:

1. PREPARE stmt;
We use UNCACHEABLE_PREPARE flag.
It is set during parsing in sql_parse.cc, mysql_new_select() for
each SELECT_LEX object and cleared at the end of PREPARE in
sql_prepare.cc, init_stmt_after_parse(). If this flag is set
subquery becomes non-const and evaluation does not happen.

2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which
   process FRM files
We use LEX::view_prepare_mode field. We set it before
view preparation and check this flag in
::fix_fields(), ::fix_length_and_dec().
Some bugs are fixed using this approach,
some are not(Bug#57352, Bug#57703). The problem here is
that we have a lot of ::fix_fields(), ::fix_length_and_dec()
where we use Item::val_...() calls for const items.

3. Derived tables with subquery = wrong result(Bug19077)
The reason of this bug is too early subquery evaluation.
It was fixed by adding Item::with_subselect field
The check of this field in appropriate places prevents
const item evaluation if the item have subquery.
The fix for Bug19077 fixes only the problem with
convert_constant_item() function and does not cover
other places(::fix_fields(), ::fix_length_and_dec() again)
where subqueries could be evaluated.

Example:
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
DROP TABLE t1;

4. Derived tables with subquery where subquery
   is evaluated before table locking(Bug#54475, Bug#52157)

Suggested solution is following:

-Introduce new field LEX::context_analysis_only with the following
 possible flags:
 #define CONTEXT_ANALYSIS_ONLY_PREPARE 1
 #define CONTEXT_ANALYSIS_ONLY_VIEW    2
 #define CONTEXT_ANALYSIS_ONLY_DERIVED 4
-Set/clean these flags when we perform
 context analysis operation
-Item_subselect::const_item() returns
 result depending on LEX::context_analysis_only.
 If context_analysis_only is set then we return
 FALSE that means that subquery is non-const.
 As all subquery types are wrapped by Item_subselect
 it allow as to make subquery non-const when
 it's necessary.

  
On this platform we seem to get lots of other signals
while waiting for SIGKILL to be delivered.

Solution: use sigsuspend(<all signals blocked>)

Auto increment value wraps when performing a bulk insert with
auto_increment_increment and auto_increment_offset greater than
one.
The fix:
If overflow happened then return MAX_ULONGLONG value as an
indication of overflow and check this before storing the
value into the field in update_auto_increment().

Explain fails at fix_fields stage and some items are left unfixed,
particulary Item_group_concat. Item_group_concat::orig_args field
is uninitialized in this case and Item_group_concat::print call 
leads to crash.
The fix:
move the initialization of Item_group_concat::orig_args
into constructor.

The tests generates 4 Billion rows which timeouts.

Removed the test from the default weekly run.

 my_seek() and my_tell() functions now honour MY_WME flag.

Fixed the references to security_ctx->priv_user
to be real char * pointers instead of a C array name reference.
This is somehow important for some 3d party 
dtrace replacements

  
On this platform we seem to get lots of other signals
while waiting for SIGKILL to be delivered.

Solution: use sigsuspend(<all signals blocked>)

DROP/CREATE SCHEMA, CREATE TABLE, REPAIR.

The cause of assert was concurrent execution of
DROP DATABASE and REPAIR TABLE where first statement
deleted table's file .TMD at the same time as
REPAIR TABLE tried to read file details from the old file
that was just removed.

Additionally was fixed trouble when DROP TABLE try delete
all files belong to table being dropped at the same time
when REPAIR TABLE statement has just deleted .TMD file.

No regression test added because this would require adding a
sync point to mysys/my_redel.c. Since this bug is not present in
5.5+, adding test coverage was considered unnecessary.
The patch has been verified using RQG testing.

mysqltest checks if the stmt is one that should be run in ps mode,
  but regexp doesn't match if preceeded by /* */ comment.
Fix: match function will jump over /*..*/ if found at start

Backported use of setenv() from 5.5
This will remove the leak on systems that have setenv()
I have not fixed the string.c leak, it's a local variable
   that the cleanup function cannot access.

Fixed some errors
Added note about 'no' prefix to options
See also follow-up comment to bug report

Workaround: add --loose-skip-innodb-use-native-aio
Only on linux if explicitly using --mem or setting $OPT_MEM

Add check that there is a RHS of the expression
Added to mysqltest.test

Var's string value was not 0-terminated if intially null.
While at it, also removed some reported memory leaks
Added sanity check, setting val_len=0 if val==0

Added option --debug-common which sets 'd' debug flags to the suggested list