Backport from 6.0 to 5.1.
Only those sync points are included, which are used in debug_sync.test.

  The Debug Sync Facility allows to place synchronization points
  in the code:
  
  open_tables(...)
  
  DEBUG_SYNC(thd, "after_open_tables");
  
  lock_tables(...)
  
  When activated, a sync point can
  
  - Send a signal and/or
  - Wait for a signal
  
  Nomenclature:
  
  - signal:            A value of a global variable that persists
                       until overwritten by a new signal. The global
                       variable can also be seen as a "signal post"
                       or "flag mast". Then the signal is what is
                       attached to the "signal post" or "flag mast".
  
  - send a signal:     Assign the value (the signal) to the global
                       variable ("set a flag") and broadcast a
                       global condition to wake those waiting for
                       a signal.
  
  - wait for a signal: Loop over waiting for the global condition until
                       the global value matches the wait-for signal.
  
  Please find more information in the top comment in debug_sync.cc
  or in the worklog entry.

The bug is not related to MERGE table or TRIGGER. More correct description
would be 'assertion on multi-table UPDATE + NATURAL JOIN + MERGEABLE VIEW'.
On PREPARE stage(see test case) we call mark_common_columns() func which
creates ON condition for NATURAL JOIN and sets appropriate
table read_set bitmaps for fields which are used in ON condition.
On EXECUTE stage mark_common_columns() is not called, we set
necessary read_set bitmaps in setup_conds(). But 'B.f1' field
is already processed and related item alredy fixed before
setup_conds() as updated field and setup_conds can not set
read_set bitmap because of that.
The fix is to set read_set bitmap for appropriate table field even
if Item_direct_view_ref item which represents a refernce to this field
is fixed.

Add --help option.

by Svoj over e-mail.

Bug#46958: Assertion in Diagnostics_area::set_ok_status, 
trigger, merge table
            
The problem with break statements is that they have very
local effects. Hence a break statement within the inner loop
of a nested-loops join caused execution to proceed to the
next table even though a serious error occurred. The problem
was fixed by breaking out the inner loop into its own
method. The change empowers all errors to terminate the
execution.
            
The errors that will now halt multi-DELETE execution
altogether are 
  - triggers returning errors
  - handler errors
  - server being killed

All statements executed by mysql_upgrade are binlogged and then are replicated to slave.
This will result in some errors. The report of this bug has demonstrated some examples.

Master and slave should be upgraded separately. All statements executed by
mysql_upgrade will not be binlogged. 
--write-binlog and --skip-write-binlog options are added into mysql_upgrade. 
These options control whether sql statements are binlogged or not. 

      
In RBR, 'DROP TEMPORARY TABLE IF EXISTS...' statement is binlogged when the table
does not exist.
      
In fact, 'DROP TEMPORARY TABLE ...' statement should never be binlogged in RBR
no matter if the table exists or not. 
This patch addresses this by checking whether we are dropping a
temporary table or not, when building the custom drop statement.

HA_ERR_WRONG_INDEX
      
In RBR, disabling keys on slave table will break replication when
updating or deleting a record. When the slave thread tries to
find the row, by searching in the storage engine, it checks
whether the table has a key or not. If it has one, then the slave
thread uses it to search the record.
      
Nonetheless, the slave only checks whether the key exists or not,
it does not verify if it is active. Should the key be
disabled (eg, DBA has issued an ALTER TABLE ... DISABLE KEYS)
then it will result in error: HA_ERR_WRONG_INDEX.
      
This patch addresses this issue by making the slave thread also
check whether the key is active or not before actually using it.

The failure is not reproduced on 5.1, so enable the 'rpl_cross_version' test.

Network error happened here, but it can be caused by CR_CONNECTION_ERROR, 
CR_CONN_HOST_ERROR, CR_SERVER_GONE_ERROR, CR_SERVER_LOST, ER_CON_COUNT_ERROR, 
and ER_SERVER_SHUTDOWN. We just check CR_SERVER_LOST here, so the test fails.

To fix the problem, check all errors that can be cause by the master shutdown.

from test-extra tree.

Changes include improvements to error handling and are based on WL#4685

 - Create the "dummy" thread joinable and wait for it to
   exit before continuing in 'my_thread_global_init'
 - This way we know that the pthread library is initialized
   by one thread only

with gcc 4.3.2

Cleaning up warnings not present in 5.0.

when compiled with Sun Studio compiler).

The thing is that Sun Studio compiler calls destructor of stack
objects when pthread_exit() is called. That triggered an assertion
in DBUG_ENTER()/DBUG_RETURN() validation logic (if DBUG_ENTER() is
used in the beginning of function, all returns should be replaced
by DBUG_RETURN/DBUG_VOID_RETURN macros).

A fix is to explicitly use DBUG_LEAVE macro.

                               value from the index (PRIMARY)


With the fix for BUG#46760, we correctly flag the presence of row_type 
only when it's actually changed and enables the FAST ALTER TABLE which was
disabled with the BUG#39200.

So the changes made by BUG#46760 makes MySQL data dictionaries to be out of 
sync but they are handled already by InnoDB with this BUG#44030.

The test was originally written to handle this but we requested Innodb to
update the test as the data dictionaries were in sync after the fix for 
BUG#39200.

Adjusting the innodb-autoinc testcase as mentioned in the comments.

the fix is reverted from 5.1, mysql-pe as 
unnecessary(no valgrind warnings there).

The "socket" variable is not available on Windows even though
the --socket option can be used to specify the pipe name for
local connections that use a named pipe.

The solution is to ensure that the variable is always defined.

checksum)"

The problem was that checksum of GEOMETRY type used memory addresses
in the computation, making it un-repeatable thus useless.
(This patch is a backport from 6.0 branch)