Early patch submitted for discussion.

It is possible for more than one thread to enter the condition
in query_cache_insert(), but the condition predicate is to
signal one thread each time the cache status changes between
the following states: {NO_FLUSH_IN_PROGRESS,FLUSH_IN_PROGRESS,
TABLE_FLUSH_IN_PROGRESS}

Consider three threads THD1, THD2, THD3

   THD2: select ... => Got a writer in ::store_query
   THD3: select ... => Got a writer in ::store_query
   THD1: flush tables => qc status= FLUSH_IN_PROGRESS;
                      new writers are blocked.
   THD2: select ... => Still got a writer and enters cond in
                       query_cache_insert
   THD3: select ... => Still got a writer and enters cond in
                       query_cache_insert
   THD1: flush tables => finished and signal status change.
   THD2: select ... => Wakes up and completes the insert.
   THD3: select ... => Happily waiting for better times. Why hurry?

This patch is a refactoring of this lock system. It introduces four new methods:
   Query_cache::try_lock()
   Query_cache::lock()
   Query_cache::lock_and_suspend()
   Query_cache::unlock()

This change also deprecates wait_while_table_flush_is_in_progress(). All threads are
queued and put on a conditional wait. On each unlock the queue is signalled. This resolve
the issues with left over threads. To assure that no threads are spending unnecessary
time waiting a signal broadcast is issued every time a lock is taken before a full
cache flush.

mysql-test/r/query_cache_debug.result:
  * Added test case for bug43758
mysql-test/t/query_cache_debug.test:
  * Added test case for bug43758
sql/sql_cache.cc:
  * Replaced calls to wait_while_table_flush_is_in_progress() with
    calls to try_lock(), lock_and_suspend() and unlock().
  * Renamed enumeration Cache_status to Cache_lock_status.
  * Renamed enumeration items to UNLOCKED, LOCKED_NO_WAIT and LOCKED.
    If the LOCKED_NO_WAIT lock type is used to lock the query cache, other
    threads using try_lock() will fail to acquire the lock.
    This is useful if the query cache is temporary disabled due to 
    a full table flush.
sql/sql_cache.h:
  * Replaced calls to wait_while_table_flush_is_in_progress() with
    calls to try_lock(), lock_and_suspend() and unlock().
  * Renamed enumeration Cache_status to Cache_lock_status.
  * Renamed enumeration items to UNLOCKED, LOCKED_NO_WAIT and LOCKED.
    If the LOCKED_NO_WAIT lock type is used to lock the query cache, other
    threads using try_lock() will fail to acquire the lock.
    This is useful if the query cache is temporary disabled due to 
    a full table flush.

Re-enabled tests main.init_connect and rpl.rpl_init_slave.test for non-Windows
platforms.

Please remove this code upon fixing the bug.

Backport to MySQL 5.0/1 fix by Vladislav Vaintroub:

In Vista and later and also in when using terminal services, when
server is started from  command line, client cannot connect to it
via shared memory protocol.

This is a regression introduced when  Bug#24731 was fixed.  The
reason is that client is trying to attach to shared memory using
global kernel object  namespace (all kernel objects are prefixed
with Global\). However, server started from the command line in
Vista and later will create shared memory and events using current
session namespace. Thus, client is unable to find the server and
connection fails.

The fix for the client is to first try to find server using "local"
names  (omitting Global\  prefix) and only if server is not found,
trying global namespace.

This test uses SHOW STATUS and the like, which may be unstable in the face
of logging to table, since the CSV handler is actively executing operations
and thus incrementing the counters.

Fixed by disabling logging to table for the duration of the test and restoring
it afterwards. This causes various counters to properly start counting from zero
and never advance due to CSV operations.

Needed for substitution in some tests.

mysql-test/suite/funcs_1/t/ndb_storedproc_06.tes:
  Remove unused file.
mysql-test/suite/funcs_1/t/ndb_storedproc_08.tes:
  Remove unused file.
mysql-test/suite/ndb/my.cnf:
  Export the socket path.

with gcc 4.3.2
      
Compiling MySQL with gcc 4.3.2 and later produces a number of 
warnings, many of which are new with the recent compiler
versions.
      
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number 
of the warnings, predominantly "suggest using parentheses 
around && in ||", and empty for and while bodies.

This variable is defined by default and one should not do it
directly as the socket variable is not available on Windows.

the --big-test flag is supplied. Test is too resource intensive
under normal valgrind runs (takes more than 30min on powerful
hardware).

mysql-test/include/no_valgrind_without_big.inc:
  Add MTR prerequisite file by Matthias Leich.
mysql-test/suite/funcs_1/t/myisam_views.test:
  Test is too resource intensive under "Valgrind".

with gcc 4.3.2

Compiling MySQL with gcc 4.3.2 and later produces a number of 
warnings, many of which are new with the recent compiler
versions.

This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number 
of the warnings, predominantly "suggest using parentheses 
around && in ||", and empty for and while bodies.

mysql-test/t/count_distinct3.test:
  Test is resource intensive.

Under a debug run, the trace file grows to a few gigabytes.
Under valgrind, takes more then 20 minutes due to the high
number of insert statements.

mysql-test/t/multi_update2.test:
  Skip under --valgrind and --debug.

variable. The problem was that THD::connect_utime could be
used without being initialized when the main thread is used
to handle connections (--thread-handling=no-threads).

sql/mysqld.cc:
  Set THD::start_utime even in no-threads handling mode.
sql/sql_class.cc:
  Initialize variable.
sql/sql_class.h:
  Rename connect_utime to prior_thr_create_utime as to
  better reflect it's use intention.
sql/sql_connect.cc:
  Check only if a thread was actually created.

Under a debug run, the trace file grows to a few gigabytes.
Under valgrind, takes more then 20 minutes due to the high
number of insert statements.

mysql-test/t/multi_update2.test:
  Skip under --valgrind and --debug.

            uninitialized variable used as subscript

Grouping select from a "constant" InnoDB table (a table
of a single row) joined with other tables caused a crash.


mysql-test/r/innodb_mysql.result:
  Added test case for bug bug #44886.
mysql-test/t/innodb_mysql.test:
  Added test case for bug bug #44886.
sql/sql_select.cc:
  Bug #44886: SIGSEGV in test_if_skip_sort_order() -
              uninitialized variable used as subscript
  
  1. The test_if_order_by_key function returned unitialized
     used_key_parts parameter in case of a "constant" InnoDB
     table. Calling function uses this parameter values as
     an array index, thus sometimes it caused a crash.
     The test_if_order_by_key function has been modified
     to set used_key_parts to 0 (no need for ordering).
  
  2. The test_if_skip_sort_order function has been
     modified to accept zero used_key_parts value and
     to prevent an array access by negative index.

client/mysqltest.c:
  Don't mix declarations and code.
  Tid up function code.

use same (slightly unwieldy) name in all trees; fix before this version goes "public".
bless ctype to avoid upmerge conflict, le sigh.

The problem is that when a optimization of read-only transactions
(bypass 2-phase commit) was implemented, it removed the code that
reseted the XID once a transaction wasn't active anymore:

sql/sql_parse.cc:

-  bzero(&thd->transaction.stmt, sizeof(thd->transaction.stmt));
-  if (!thd->active_transaction())
-    thd->transaction.xid_state.xid.null();
+  thd->transaction.stmt.reset();

This mostly worked fine as the transaction commit and rollback
functions (in handler.cc) reset the XID once the transaction is
ended. But those functions wouldn't reset the XID in case of
a empty transaction, leading to a assertion when a new starting
a new XA transaction.

The solution is to ensure that the XID state is reset when empty
transactions are ended (by either commit or rollback). This is
achieved by reorganizing the code so that the transaction cleanup
routine is invoked whenever a transaction is ended.

mysql-test/r/xa.result:
  Add test case result for Bug#44672
mysql-test/t/xa.test:
  Add test case for Bug#44672
sql/handler.cc:
  Invoke transaction cleanup function whenever a transaction is
  ended. Move XID state reset logic to the transaction cleanup
  function.
sql/sql_class.h:
  Add XID state reset logic.

a binary distribution of the server as the MTR valgrind option
relies on it to silence unmeaningful warnings.

mysql-test/Makefile.am:
  Install valgrind.supp as part of the test suite.
  Remove reference to inexistent directory.

Implemented a way to circumvent the always true comparison by
having nested macros (as suggested on review).

Merged the 5.0 fix to 5.1 and fixed the 5.1 specific warnings.

Fixed the 5.0-bugteam MacOSX warnings.

client/mysqldump.c:
  Bug #45286: typecasts
cmd-line-utils/readline/bind.c:
  Bug #45286: use variable of right type
cmd-line-utils/readline/display.c:
  Bug #45286: use variable of right type
dbug/user.r:
  Bug #45286: no warnings in generating man pages
strings/ctype.c:
  Bug #45286: typecasts