updates

Attempt to execute trigger or stored function with multi-UPDATE
which used - but didn't update - a table that was also used by
the calling statement led to an error. Read-only reference to
tables used in the calling statement should be allowed.
 
This problem was caused by the fact that check for conflicting
use of tables in SP/triggers was performed in open_tables(),
and in case of multi-UPDATE we didn't know exact lock type at
this stage.

We solve the problem by moving this check to lock_tables(), so
it can be performed after exact lock types for tables used by
multi-UPDATE are determined.


mysql-test/r/trigger.result:
  Results for the added test case is added.
mysql-test/t/trigger.test:
  A new test case is added, verifying correct table multi-update
  conflict resolution, both read-only and write.
sql/sql_base.cc:
  The check for conflicting use of tables in SP/triggers is moved
  to lock_tables(), to be performed after the exact lock types
  have been determined. Also, an assert is added to open_ltable()
  to ensure this func is not used in a prelocked context.

  
UNION could convert fixed-point FLOAT(M,D)/DOUBLE(M,D) columns  
to FLOAT/DOUBLE when aggregating data types from the SELECT  
substatements. While there is nothing particularly wrong with  
this behavior, especially when M is greater than the hardware  
precision limits, it could be confusing in cases when all  
SELECT statements in a union have the same  
FLOAT(M,D)/DOUBLE(M,D) columns with equal precision  
specifications listed in the same position.  
  
Since the manual is quite vague on what data type should be  
returned in such cases, the bug was fixed by implementing the  
most 'expected' behavior: do not convert FLOAT(M,D)/DOUBLE(M,D)  
to anything else if all SELECT statements in a UNION have the  
same precision for that column.  

mysql-test/r/union.result:
  Added a test case for bug #43432.
mysql-test/t/union.test:
  Added a test case for bug #43432.
sql/field.cc:
  Replaced FLT_DIG+6 and DBL_DIG+7 with a symbolic constant.
sql/item.cc:
  Do not convert FLOAT(M,D)/DOUBLE(M,D) 
  to anything else if all SELECT statements in a UNION have the 
  same precision for that column.
sql/mysql_priv.h:
  Added a symbolic constant for FLT_DIG+6 and DBL_DIG+7.

Problem: commit doesn't delete savepoints if there are no changes 
in the transaction.

Fix: delete them in such cases.


mysql-test/r/innodb_mysql.result:
  Fix for bug #26288: savepoint not deleted, comit on empty transaction
    - test result.
mysql-test/t/innodb_mysql.test:
  Fix for bug #26288: savepoint not deleted, comit on empty transaction
    - test case.
sql/handler.cc:
  Fix for bug #26288: savepoint not deleted, comit on empty transaction
    - call transaction.cleanup() even if nht is 0 to delete 
  possible savepoints.

The problem is that the read and write methods of the shared
memory transport (protocol) didn't react to asynchronous close
events, which could lead to a lock up as the client would wait
(until time out) for a server response that will never come.

The solution is to also wait for close events while waiting
for I/O from or to the server.

mysql-test/r/shm.result:
  Add test case result for Bug#33899
mysql-test/t/shm.test:
  Add test case for Bug#33899
vio/viosocket.c:
  Also wait for close events.

      
When add an aliase name after NAME_CONST, the aliase name will be overwrite.
      
NAME_CONST will re-set the field's name only if there isn't an aliase in the
function fix-fields().
If there is an aliase, NAME_CONST doesn't re-set the field's name and keeps the old
name.

mysql-test/r/func_misc.result:
  Test result.
mysql-test/r/rpl_name_const.result:
  Test case.
mysql-test/t/func_misc.test:
  Add NAME_CONST test.
mysql-test/t/rpl_name_const.test:
  Test result.
sql/item.cc:
  Re-set field's name if the name is autogenerated, that mean without aliase.

            
After the table is compressed by the myisampack utility,
opening the table by the server produces valgrind warnings.
      
This happens because when we try to read a record into the buffer
we alway assume that the remaining buffer to read is always equal 
to word size(4 or 8 or 2 bytes) we read. Sometimes we have 
remaining buffer size less than word size and trying to read the 
entire word size will end up in valgrind errors.
            
Fixed by reading byte by byte when we detect the remaining buffer 
size is less than the word size.

myisam/mi_packrec.c:
  Fixed fill_buffer() to read byte by byte when the remaining 
  buffer size is less than word size.
mysql-test/r/myisampack.result:
  Result file for BUG#41541
mysql-test/t/myisampack.test:
  Testcase for BUG#41541

                    expired timeout on debx86-b in PB 

Moved the resource-intensive test case for bug #41486 into 
a separate test file to reduce execution time for mysql.test. 


mysql-test/include/wait_until_disconnected.inc:
  Used in mysql-bug41486.test.
mysql-test/r/mysql-bug41486.result:
  Moved the resource-intensive test case for bug #41486 into 
  a separate test file to reduce execution time for mysql.test.
mysql-test/r/mysql.result:
  Moved the resource-intensive test case for bug #41486 into 
  a separate test file to reduce execution time for mysql.test.
mysql-test/t/mysql-bug41486.test:
  Moved the resource-intensive test case for bug #41486 into 
  a separate test file to reduce execution time for mysql.test.
mysql-test/t/mysql.test:
  Moved the resource-intensive test case for bug #41486 into 
  a separate test file to reduce execution time for mysql.test.

                    produce incorrect results for ROUND() 

Added a workaround and a configure check to test whether 
isinf() is affected by the GCC bug #39228. 
       
Since no code in MySQL server is currently affected by that 
bug, the patch is actually a safeguard for possible future 
code modifications. No test cases or changelog entries are 
needed. 


configure.in:
  Added a configure check to test whether isinf() is safe to use
  in C code.
include/my_global.h:
  Added a workaround for GCC bug #39228.

When do 'insert delayed' operation, the time_zone info doesn't be keeped in the row info.
So when we do insert sometime later, time_zone didn't write into binlog.
This will cause wrong result for timestamp column in slave.

Our solution is that adding time_zone info with the delayed-row and
restoring time_zone from row-info when execute that row in the furture by another thread.
So we can write correct time_zone info into binlog and got correct result in slave.


mysql-test/r/rpl_timezone.result:
  Test result
mysql-test/t/rpl_timezone.test:
  Add test for bug#41719
sql/sql_insert.cc:
  Add time_zone info in the delayed-row and restore time_zone when execute the row in the furture by another thread.

   Details for Bug#43015 main.lock_multi: Weak code (sleeps etc.)
   -------------------------------------------------------------
   - The fix for bug 42003 already removed a lot of the weaknesses mentioned.
   - Tests showed that there are unfortunately no improvements of this tests
     in MySQL 5.1 which could be ported back to 5.0.
   - Remove a superfluous "--sleep 1" around line 195

   Details for Bug#43065 main.lock_multi: This test is too big if the disk is slow
   -------------------------------------------------------------------------------
   - move the subtests for the bugs 38499 and 36691 into separate scripts
   - runtime under excessive parallel I/O load after applying the fix
     lock_multi           [ pass ]          22887
     lock_multi_bug38499  [ pass ]         536926
     lock_multi_bug38691  [ pass ]         258498

When asking what database is selected, client expected
to *always* get an answer from the server.

We now handle failure more gracefully.

See comments in ticket for a discussion of what happens,
and how things interlock.


client/mysql.cc:
  Handle empty result-sets gracefully, as opposed
  to just result sets with n>0 items that may themselves
  be empty.

Don't compare string literals as it results in unspecified behavior.

mysys/default.c:
  Test for a empty string.

functions
      
Unknown timezone specifications are properly rejected
by the server, but are copied into tz_storage before
rejection, and hence is retained until end of server 
life. With sufficiently large bogus timezone specs, 
it is easy to exhaust system memory.
      
Allocation of memory for a copy of the timezone
name is delayed until after verification of validity,
at the cost of a memcpy of the timezone info. This 
only happens once, future lookups will hit the cached
structure.

for bug #41486. Session max_allowed_packet is read-only
as of MySQL 5.1.31. In addition, the global variable
now has no effect on the current session.

fixed help message


client/mysql.cc:
  fixed help message

Don't throw an error after checking the first and the second arguments.
Continue with checking the third and higher arguments and if some of
them is stronger according to coercibility rules,
then this argument's collation is set as result collation.


mysql-test/r/ctype_collate.result:
  test result
mysql-test/t/ctype_collate.test:
  test case
sql/item.cc:
  Don't throw an error after checking the first and the second arguments.
  Continue with checking the third and higher arguments and if some of
  them is stronger according to coercibility rules,
  then this argument's collation is set as result collation.

                        
When loading dump created by mysqldump tool an error is
thrown saying storage engine for the table doesn't have 
an option.
                        
mysqldump tries to re-insert the data into the federated
table which causes the error. Since the data is already
available on the remote server, mysqldump shouldn't try
to dump the data again for FEDERATED tables.
                        
As stated in the bug page, it can be considered similar
to the MERGE ENGINE with "view only" nature.
                        
Fixed by adding the "FEDERATED ENGINE" to the exception
list to ignore the data.

client/mysqldump.c:
  Fixed check_if_ignore_table() to ignore FEDERATED engine
  when dumping the table data.
mysql-test/r/federated.result:
  Result file for BUG#21360
mysql-test/t/federated.test:
  Testcase for BUG#21360

                   ~40Mb after mysqldump/import 
        
When the input string exceeds the maximum allowed size for the 
internal buffer, batch_readline() returns a truncated string. 
Since there was no way for a caller to determine whether the 
string was truncated or not, the command line client assumed 
batch_readline() to always return the whole input string and 
appended a newline character. This resulted in garbled data 
when importing dumps containing strings longer than the 
maximum input buffer size. 
  
Fixed by adding a flag to the batch_readline() interface to 
signal a truncated string to the caller. 
  
Other minor problems fixed during patch implementation: 
 
- The maximum allowed buffer size for batch_readline() was set 
up depending on the client's max_allowed_packet value. It does 
not actully make any sense, as those variables are not 
related. The input buffer size limit is now always set to 1 
MB. 
  
- fill_buffer() did not always set the EOF flag. 
 
- The input buffer could actually grow twice as the specified 
limit due to insufficient checks in intern_read_line(). 

client/my_readline.h:
  Changed the interface of batch_readline().
client/mysql.cc:
  Honor the truncated flag returned by batch_readline() and do  
  not append the newline character if it was set. Since we can't 
  change the interfaces for readline()/fgets() used in the  
  interactive mode, always assume the returned string was not  
  truncated. In addition, always set the batch_readline()  
  internal buffer to 1 MB, independently from the client's  
  max_allowed_packet.
client/readline.cc:
  Added the 'truncated' argument do batch_readline() to signal 
  truncated string to a caller. 
  Fixed fill_buffer() to set the EOF flag correctly. 
  Fixed checks in intern_read_line() to not allow the internal  
  buffer grow past the specified limit.
mysql-test/r/mysql.result:
  Added a test case for bug #41486.
mysql-test/t/mysql.test:
  Added a test case for bug #41486.