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.

SHOW DATABASES LIKE ... was not converting to lowercase on comparison as the
documentation is suggesting. 
Fixed it to behave similarly to SHOW TABLES LIKE ... and updated the failing
on MacOSX lowercase_table2 test case.

Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.

           due to GCC preprocessor change
      
The problem is that newer GCC versions treats missing headers
as fatal errors. The solution is to use a guard macro to prevent
the inclusion of system headers when checking the ABI with the
C Preprocessor.

Reference: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15638
           http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44836

           table with active trx

Essentially, the problem is that InnoDB does a implicit commit
when a cursor (table handler) is unlocked/closed, creating
a dissonance between the transaction state within the server
layer and the storage engine layer. Theoretically, a statement
transaction can encompass several table instances in a similar
manner to a multiple statement transaction, hence it does not
make sense to limit a statement transaction to the lifetime of
the table instances (cursors) used within it.

Since this particular instance of the problem is only triggerable
on 5.1 and is masked on 5.5 due 2PC being skipped (assertion is in
the prepare phase of a 2PC), the solution (which is less risky) is
to explicitly end the transaction before the cached table is unlock
on rename table.

The patch is to be null merged into trunk.

This assert checks that the server does not try to send OK to the
client if there has been some error during processing. This is done
to make sure that the error is in fact sent to the client.

The problem was that view errors during processing of WHERE conditions
in UPDATE statements where not detected by the update code. It therefore
tried to send OK to the client, triggering the assert.
The bug was only noticeable in debug builds.

This patch fixes the problem by making sure that the update code
checks for errors during condition processing and acts accordingly.

Bug#47139: Test "merge" crashes in "embedded" run

Backport patch for Bug#47139

of the "embedded" server

Problem: mysqltest_embedded failed to load ha_innodb_plugin library
on some platforms (due to some unresolved references).

Fix: on FreeBSD use -export-dynamic flag building mysqltest_embedded.
That allows to use its global symbols to resolve references in the
dynamically loaded plugin library.

Calculating the estimated number of records for a range scan
may take a significant time, and it was impossible for a user
to interrupt that process by killing the connection or the
query.

Fixed by checking the thread's 'killed' status in
check_quick_keys() and interrupting the calculation process if
it is set to a non-zero value.

           compiler problem

GCC-style inline assembly is not supported by the Sun Studio
compilers prior to version 12.

Added a check for the Sun Studio version to avoid using 
_FPU_GETCW() / _FPU_SETCW() when inline assembly is
 unsupported. This can lead to some differences in floating
point calculations on Solaris 8/x86 which, however, is not worth
bothering with Sun-style assembly .il templates.

of autoconf and is not strictly needed for now.

Although the C standard mandates that sprintf return the number
of bytes written, some very ancient systems (i.e. SunOS 4)
returned a pointer to the buffer instead. Since these systems
are not supported anymore and are hopefully long dead by now,
simply remove the portability wrapper that dealt with this
discrepancy. The autoconf check was causing trouble with GCC.

Introduce a MySQL maintainer/developer mode that enables
a set of warning options for the C/C++ compiler. This mode
is intended to help improve the overall quality of the code.

The warning options are:

C_WARNINGS="-Wall -Wextra -Wunused -Wwrite-strings -Werror"
CXX_WARNINGS="$C_WARNINGS -Wno-unused-parameter"

Since -Wall is essentially a moving target, autoconf checks
are not run with warning options enabled, in particualr -Werror.
This decision might be revisited in the future. The patch also
fixes a mistake in the makefiles, where automake CXXFLAGS would
be set to CFLAGS.

In bug-28430 HA_PRIMARY_KEY_REQUIRED_FOR_POSITION
was disabled in the partitioning engine in the first patch,
That bug was later fixed a second time, but that flag
was not removed.

No need to disable this flag, as it leads to bad
choise in row replication.

The problem there is that HAVING condition evaluates const
parts of condition despite the condition has references
on aggregate functions. Table t1 became const tables
after make_join_statistics and table1.pk = 1, HAVING is
transformed into MAX(1) < 7 and taken away from HAVING.
The fix is to skip evaluation of HAVING conts parts if
HAVING condition has references on aggregate functions.

rb://396, approved by Sunny Bains.

The handler function for reading one row from a specific index
was not optimized in the partitioning handler since it
used the default implementation.

No test case since it is performance only, verified by hand.

Fix the memory leak

was not complete. Bootstrap failed to pick up necessary files needed by test and hence
all tests failed.

(without the unrelated whitespace changes):

  ------------------------------------------------------------------------
  r7009 | jyang | 2010-04-29 20:44:56 +0300 (Thu, 29 Apr 2010) | 6 lines
  
  branches/5.0: Port fix for bug #49238 (Creating/Dropping a temporary
  table while at 1023 transactions will cause assert) from 5.1 to
  branches/5.1. Separate action for return value DB_TOO_MANY_CONCURRENT_TRXS
  from that of DB_MUST_GET_MORE_FILE_SPACE in row_drop_table_for_mysql().
  
  
  ------------------------------------------------------------------------

This crash occured after ALTER TABLE was used on a temporary
transactional table locked by LOCK TABLES. Any later attempts to
execute LOCK/UNLOCK TABLES, caused the server to crash.

The reason for the crash was the list of locked tables would
end up having a pointer to a free'd table instance. This happened
because ALTER TABLE deleted the table without also removing the
table reference from the locked tables list.

This patch fixes the problem by making sure ALTER TABLE also
removes the table from the locked tables list.

Test case added to innodb_mysql.test.

Since the original fix for this bug lowercases the search pattern it's not a 
good idea to copy the search pattern to the output instead of the real table 
name found (since, depending on the case mode these two names may differ in 
case).
Fixed the infrmation_schema.test failure by making sure the actual table 
name of an inoformation schema table is passed instead of the lookup pattern
even when the pattern doesn't contain wildcards.