sql/event.cc:
- fix TODO (remove things already done)
- check the length of the event's name and body during creation
and report an error if longer than what can be fit into
mysql.event (nothing like non-strict mode here)
- report to sql_parse.cc and error when open table failed, otherwise send_ok()
was being called and the error have become an warning.
- update function documentation a bit
- evex_db_find_routine_aux returns 0 and not EVEX_OK
sql/event_executor.cc:
- CS changes to definitions of the main and worker thread routines
- reorder code a bit to prevent crashes because of reading of
already freed data -> first wait all events to finish their work,
namely all worker threads to finish, and then destroy in-memory
structures
- more error checking and error reporting at the place of failure.
sql/event_priv.h:
code simplifying macro
sql/event_timed.cc:
CS cosmetics
sql/event.cc:
-my_error() as close as possible to the place where the error
occurs.
-a thought how to replicate events
-use close_thread_tables() in some cases and for others rely on
this call being done in sql_parse.cc::do_command()
sql/event.h:
remove redundant defines
sql/event_executor.cc:
- reenable the compilation again
- don't backup the open_tables_state, it's not needed
sql/event_timed.cc:
- inline a bit
- comment added
sql/mysqld.cc:
- start mysqld with --event-scheduler=0 by default
sql/share/errmsg.txt:
3 new messages
sql/sql_parse.cc:
remove now obsolete error checking - the errors are reported
as closer as possible to the place where they are detected
sql/sql_yacc.yy:
add WARNING message. fix a bug that was corrupting
thd->client_capabilites ->
select count(*) from mysql.event
was reporting : "Unknown table test.event"!!!
Using temporal variable is nice but IMO quite error-prone.
make more independent of SP
sql/event.cc:
use own routine - export it
sql/event_priv.h:
export these two
sql/event_timed.cc:
use own routine, don't rely on SP
sql/sp.cc:
revert changes to SP
sql/sp.h:
revert changes to SP
sql/sql_show.cc:
rever changes to SP
updated sources
sql/event.cc:
update
put some error calls to the places they occur
sql/event.h:
- change the default (does not work in STRICT mode)
sql/event_executor.cc:
move mutex initialization to evex_init_mutexes so init_events() can be reused when the
main thread does not work and set global event_scheduler=1; (this will start the thread)
The main thread is now visible with show processlist and can be killed.
sql/event_priv.h:
don't use anymore SP for opening table
sql/event_timed.cc:
don't use anymore SP routines for opening mysql.event
sql/mysqld.cc:
shutdown_events() should be maximal at the end of the server because
it destroys mutexes of EVEX. The call should not be in the main thread.
sql/set_var.cc:
make sys_var_event_executor subclass sys_var_bool_ptr
to overload ::update() method - needed to start a
killed (non-running) evex main thread
sql/set_var.h:
declare class sys_var_event_executor
sql/share/errmsg.txt:
2 new messages
- split into several files
- forbid parallel execution (before analyse is done how to make it possible)
because the same sp_head instance cannot be executed in parallel
- added GPL headers
- changed EVENT_ACL to be per DB variable
- fixed minor problems
mysql-test/lib/init_db.sql:
WL#1034 updated
- add Event_priv to mysql.user (update test)
- add updated mysql.event table struct
scripts/mysql_fix_privilege_tables.sql:
WL#1034 updated
add updated mysql.event structure
sql/Makefile.am:
split event.cc into
- event.cc (create/alter/drop)
- event_executor.cc (main and worker threads)
- event_timed.cc (class event_timed)
- event_priv.h (some definitions used internally by the module)
sql/event.cc:
- added GPL header
- split into few files
- fixed some issues after code review
- now using SP routines for opening/traversing/closing tables
(will be reverted)
sql/event.h:
- add GPL header
- remove two methods - inline them in sql_yacc.yy
- don't use absolute values for EVEX_ defines but the SP_ equivalents (have to move 100% to SP_
defines and as later step to not transfer messages upwards in the stack but
report them at the place they occur)
- updated reference table definition
- move default mem_root param from event.cc to the header
sql/mysqld.cc:
WL#1034
rename --event-executor to --event-scheduler
executor sounds a bit scary :)
sql/set_var.cc:
rename internal variable name from event_executor to event_scheduler
(ppl won't be scarried anymore :)
sql/share/errmsg.txt:
omit one %s - not needed
sql/sp_head.cc:
disable this DBUG_PRINT for a bit. m_next_cached_sp is 0x0 and I get crash here...
sql/sp_head.h:
remove m_old_cmq, a temporal variable is used in sql_yacc.yy (Serg's idea)
to keep the previous state.
$<ulong_val>$ = ....
YYTHD->client_capabilites != $<ulong_val>4;
(the same is done also for class event_timed)
sql/sql_acl.cc:
handle pre-5.1.4 table and give the user EVENT_ACL if he had CREATE_ACL
sql/sql_acl.h:
fix the bitmask
sql/sql_parse.cc:
- move from EVENT_ACL being global to EVENT_ACL being per DB like
CREATE_PROC_ACL
- lex->m_qname dropped, because not needed, fix code therefore
- add comment that SHOW CREATE EVENT has to be implemented
sql/sql_yacc.yy:
- use temporal variable of Bison to store a short lived value
- fix indentation
- inline 2 class event_timed methods in the parser
sql/tztime.h:
be more expressive - it's already extern
The previous variant where it was a specific ha_partition method
only worked for the partition handler. It was unfortunately called also
for the NDB handler and in this case it called a random method in the
NDB handler with random input.
sql/ha_ndbcluster.cc:
Moved initialisation of some handler variables to
set_part_info method called earlly in the open process
sql/ha_ndbcluster.h:
Moved initialisation of some handler variables to
set_part_info method called earlly in the open process
sql/ha_partition.h:
Made set_part_info a handler method and not a ha_partition method only
sql/handler.h:
Made set_part_info a handler method and not a ha_partition method only
sql/sql_partition.cc:
Made set_part_info a handler method and not a ha_partition method only
into zim.(none):/home/brian/mysql/mysql-5.1-new
client/mysqldump.c:
Auto merged
mysql-test/r/mysqldump.result:
REsolve
mysql-test/t/mysqldump.test:
Resolve conflict
So, use --replace and instead of getting INSERT INTO you will INSTEAD get REPLACE INTO. Buyer beward, REPLACE is a MySQL SQL, so you will not end up with a dump that can be used for other databases.
Though I hear you could just use a sed line to modify it back :)
client/client_priv.h:
New option for --replace
client/mysqldump.c:
Added option for REPLACE INTO instead of INSERT INTO
mysql-test/r/mysqldump.result:
Updated REsultes for replace into
mysql-test/t/mysqldump.test:
Added new test for --replace
into mysql.com:/home/my/mysql-5.1-TDC
sql/handler.cc:
Auto merged
sql/opt_range.cc:
Auto merged
sql/sql_insert.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
Removed valgrind warnings when using not aligned bitmap buffer size
Added setting of thread_stack
include/my_bitmap.h:
Added bitmap_buffer_size()
sql/handler.cc:
use bitmap_buffer_size()
sql/opt_range.cc:
use bitmap_buffer_size()
sql/sql_insert.cc:
Use bitmap_buffer_size()
sql/sql_parse.cc:
Added setting of thread_stack when taking thread from thread cache
sql/sql_plugin.cc:
Set thread_stack
into mysql.com:/home/my/mysql-5.1-TDC
sql/ha_federated.cc:
Auto merged
sql/mysql_priv.h:
Auto merged
sql/slave.cc:
Auto merged
sql/sql_acl.cc:
Auto merged
sql/sql_base.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_insert.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/examples/ha_tina.cc:
Auto merged
sql/examples/ha_tina.h:
Auto merged
sql/unireg.h:
Auto merged
into mysql.com:/home/my/mysql-5.1
BitKeeper/etc/ignore:
auto-union
include/my_global.h:
Auto merged
mysql-test/mysql-test-run.pl:
Auto merged
mysql-test/r/grant.result:
Auto merged
sql/ha_federated.cc:
Auto merged
sql/mysql_priv.h:
Auto merged
sql/slave.cc:
Auto merged
sql/sql_acl.cc:
Auto merged
sql/sql_base.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/examples/ha_tina.h:
Auto merged
sql/sql_insert.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_udf.cc:
Auto merged
sql/tztime.cc:
Auto merged
sql/unireg.h:
Auto merged
sql/examples/ha_tina.cc:
manual merge
sql/share/errmsg.txt:
manual merge
Larger stack size neaded for open table on x86 64 bit
Fix failing test cases
Deleted symlink from bk
BitKeeper/etc/ignore:
added libmysqld/ha_blackhole.cc
BitKeeper/deleted/.del-ha_blackhole.cc~727c69ef7846623a:
Delete: libmysqld/ha_blackhole.cc
include/my_global.h:
Don't use PATH_MAX for FN_REFLEN as this uses too much stack space.
(With a PATH_MAX of 4096, we use 80K for opening a table as there is several objects of size FN_REFLEN on stack)
mysql-test/r/federated.result:
Update results after error message changes
mysql-test/r/grant.result:
Update results after error message changes
mysql-test/r/grant2.result:
Update results after error message changes
sql/ha_federated.cc:
Fix error messages to be more consistent
sql/mysql_priv.h:
Stack size to have when opening a table
(This was needed on x86 64 bit Linux)
sql/share/errmsg.txt:
Remove quotes around error string for federated as two quotes in the output looks strange
sql/sql_base.cc:
More correct stack size
sql/sql_parse.cc:
Set thread_stack before store_globals()
sql/unireg.h:
More correct MAX_DBKEY_LENGTH
into mysql.com:/home/my/mysql-5.1-TDC
mysql-test/r/variables.result:
Auto merged
mysql-test/t/variables.test:
Auto merged
sql/ha_berkeley.cc:
Auto merged
sql/ha_federated.cc:
Auto merged
sql/ha_federated.h:
Auto merged
sql/ha_innodb.cc:
Auto merged
sql/ha_myisammrg.cc:
Auto merged
sql/ha_ndbcluster.cc:
Auto merged
sql/handler.cc:
Auto merged
sql/item.cc:
Auto merged
sql/item.h:
Auto merged
sql/item_cmpfunc.cc:
Auto merged
sql/item_func.cc:
Auto merged
sql/item_subselect.cc:
Auto merged
sql/item_sum.cc:
Auto merged
sql/item_timefunc.cc:
Auto merged
sql/key.cc:
Auto merged
sql/mysqld.cc:
Auto merged
sql/opt_range.cc:
Auto merged
sql/parse_file.cc:
Auto merged
sql/set_var.cc:
Auto merged
sql/slave.cc:
Auto merged
sql/sp.cc:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sp_head.h:
Auto merged
sql/sql_acl.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_class.h:
Auto merged
sql/sql_lex.cc:
Auto merged
sql/sql_lex.h:
Auto merged
sql/sql_load.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_select.cc:
Auto merged
sql/sql_show.cc:
Auto merged
sql/sql_table.cc:
Auto merged
sql/sql_trigger.cc:
Auto merged
sql/sql_view.cc:
Auto merged
sql/structs.h:
Auto merged
sql/field.cc:
Merge with global tree
sql/sql_base.cc:
Merge with global tree
sql/table.cc:
Merge with global tree
The table opening process now works the following way:
- Create common TABLE_SHARE object
- Read the .frm file and unpack it into the TABLE_SHARE object
- Create a TABLE object based on the information in the TABLE_SHARE
object and open a handler to the table object
Other noteworthy changes:
- In TABLE_SHARE the most common strings are now LEX_STRING's
- Better error message when table is not found
- Variable table_cache is now renamed 'table_open_cache'
- New variable 'table_definition_cache' that is the number of table defintions that will be cached
- strxnmov() calls are now fixed to avoid overflows
- strxnmov() will now always add one end \0 to result
- engine objects are now created with a TABLE_SHARE object instead of a TABLE object.
- After creating a field object one must call field->init(table) before using it
- For a busy system this change will give you:
- Less memory usage for table object
- Faster opening of tables (if it's has been in use or is in table definition cache)
- Allow you to cache many table definitions objects
- Faster drop of table
mysql-test/mysql-test-run.sh:
Fixed some problems with --gdb option
Test both with socket and tcp/ip port that all old servers are killed
mysql-test/r/flush_table.result:
More tests with lock table with 2 threads + flush table
mysql-test/r/information_schema.result:
Removed old (now wrong) result
mysql-test/r/innodb.result:
Better error messages (thanks to TDC patch)
mysql-test/r/merge.result:
Extra flush table test
mysql-test/r/ndb_bitfield.result:
Better error messages (thanks to TDC patch)
mysql-test/r/ndb_partition_error.result:
Better error messages (thanks to TDC patch)
mysql-test/r/query_cache.result:
Remove tables left from old tests
mysql-test/r/temp_table.result:
Test truncate with temporary tables
mysql-test/r/variables.result:
Table_cache -> Table_open_cache
mysql-test/t/flush_table.test:
More tests with lock table with 2 threads + flush table
mysql-test/t/merge.test:
Extra flush table test
mysql-test/t/multi_update.test:
Added 'sleep' to make test predictable
mysql-test/t/query_cache.test:
Remove tables left from old tests
mysql-test/t/temp_table.test:
Test truncate with temporary tables
mysql-test/t/variables.test:
Table_cache -> Table_open_cache
mysql-test/valgrind.supp:
Remove warning that may happens becasue threads dies in different order
mysys/hash.c:
Fixed wrong DBUG_PRINT
mysys/mf_dirname.c:
More DBUG
mysys/mf_pack.c:
Better comment
mysys/mf_tempdir.c:
More DBUG
Ensure that we call cleanup_dirname() on all temporary directory paths.
If we don't do this, we will get a failure when comparing temporary table
names as in some cases the temporary table name is run through convert_dirname())
mysys/my_alloc.c:
Indentation fix
sql/examples/ha_example.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/examples/ha_example.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/examples/ha_tina.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/examples/ha_tina.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/field.cc:
Update for table definition cache:
- Field creation now takes TABLE_SHARE instead of TABLE as argument
(This is becasue field definitions are now cached in TABLE_SHARE)
When a field is created, one now must call field->init(TABLE) before using it
- Use s->db instead of s->table_cache_key
- Added Field::clone() to create a field in TABLE from a field in TABLE_SHARE
- make_field() takes TABLE_SHARE as argument instead of TABLE
- move_field() -> move_field_offset()
sql/field.h:
Update for table definition cache:
- Field creation now takes TABLE_SHARE instead of TABLE as argument
(This is becasue field definitions are now cached in TABLE_SHARE)
When a field is created, one now must call field->init(TABLE) before using it
- Added Field::clone() to create a field in TABLE from a field in TABLE_SHARE
- make_field() takes TABLE_SHARE as argument instead of TABLE
- move_field() -> move_field_offset()
sql/ha_archive.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_archive.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_berkeley.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Changed name of argument create() to not hide internal 'table' variable.
table->s -> table_share
sql/ha_berkeley.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_blackhole.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_blackhole.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_federated.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Fixed comments
Remove index variable and replace with pointers (simple optimization)
move_field() -> move_field_offset()
Removed some strlen() calls
sql/ha_federated.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_heap.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Simplify delete_table() and create() as the given file names are now without extension
sql/ha_heap.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_innodb.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_innodb.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_myisam.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Remove not needed fn_format()
Fixed for new table->s structure
sql/ha_myisam.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_myisammrg.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Don't set 'is_view' for MERGE tables
Use new interface to find_temporary_table()
sql/ha_myisammrg.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Added flag HA_NO_COPY_ON_ALTER
sql/ha_ndbcluster.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Fixed wrong calls to strxnmov()
Give error HA_ERR_TABLE_DEF_CHANGED if table definition has changed
drop_table -> intern_drop_table()
table->s -> table_share
Move part_info to TABLE
Fixed comments & DBUG print's
New arguments to print_error()
sql/ha_ndbcluster.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_partition.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
We can't set up or use part_info when creating handler as there is not yet any table object
New ha_intialise() to work with TDC (Done by Mikael)
sql/ha_partition.h:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
Got set_part_info() from Mikael
sql/handler.cc:
We new use TABLE_SHARE instead of TABLE when creating engine handlers
ha_delete_table() now also takes database as an argument
handler::ha_open() now takes TABLE as argument
ha_open() now calls ha_allocate_read_write_set()
Simplify ha_allocate_read_write_set()
Remove ha_deallocate_read_write_set()
Use table_share (Cached by table definition cache)
sql/handler.h:
New table flag: HA_NO_COPY_ON_ALTER (used by merge tables)
Remove ha_deallocate_read_write_set()
get_new_handler() now takes TABLE_SHARE as argument
ha_delete_table() now gets database as argument
sql/item.cc:
table_name and db are now LEX_STRING objects
When creating fields, we have now have to call field->init(table)
move_field -> move_field_offset()
sql/item.h:
tmp_table_field_from_field_type() now takes an extra paramenter 'fixed_length' to allow one to force usage of CHAR
instead of BLOB
sql/item_cmpfunc.cc:
Fixed call to tmp_table_field_from_field_type()
sql/item_create.cc:
Assert if new not handled cast type
sql/item_func.cc:
When creating fields, we have now have to call field->init(table)
dummy_table used by 'sp' now needs a TABLE_SHARE object
sql/item_subselect.cc:
Trivial code cleanups
sql/item_sum.cc:
When creating fields, we have now have to call field->init(table)
sql/item_timefunc.cc:
Item_func_str_to_date::tmp_table_field() now replaced by call to
tmp_table_field_from_field_type() (see item_timefunc.h)
sql/item_timefunc.h:
Simply tmp_table_field()
sql/item_uniq.cc:
When creating fields, we have now have to call field->init(table)
sql/key.cc:
Added 'KEY' argument to 'find_ref_key' to simplify code
sql/lock.cc:
More debugging
Use create_table_def_key() to create key for table cache
Allocate TABLE_SHARE properly when creating name lock
Fix that locked_table_name doesn't test same table twice
sql/mysql_priv.h:
New functions for table definition cache
New interfaces to a lot of functions.
New faster interface to find_temporary_table() and close_temporary_table()
sql/mysqld.cc:
Added support for table definition cache of size 'table_def_size'
Fixed som calls to strnmov()
Changed name of 'table_cache' to 'table_open_cache'
sql/opt_range.cc:
Use new interfaces
Fixed warnings from valgrind
sql/parse_file.cc:
Safer calls to strxnmov()
Fixed typo
sql/set_var.cc:
Added variable 'table_definition_cache'
Variable table_cache renamed to 'table_open_cache'
sql/slave.cc:
Use new interface
sql/sp.cc:
Proper use of TABLE_SHARE
sql/sp_head.cc:
Remove compiler warnings
We have now to call field->init(table)
sql/sp_head.h:
Pointers to parsed strings are now const
sql/sql_acl.cc:
table_name is now a LEX_STRING
sql/sql_base.cc:
Main implementation of table definition cache
(The #ifdef's are there for the future when table definition cache will replace open table cache)
Now table definitions are cached indepndent of open tables, which will speed up things when a table is in use at once from several places
Views are not yet cached; For the moment we only cache if a table is a view or not.
Faster implementation of find_temorary_table()
Replace 'wait_for_refresh()' with the more general function 'wait_for_condition()'
Drop table is slightly faster as we can use the table definition cache to know the type of the table
sql/sql_cache.cc:
table_cache_key and table_name are now LEX_STRING
'sDBUG print fixes
sql/sql_class.cc:
table_cache_key is now a LEX_STRING
safer strxnmov()
sql/sql_class.h:
Added number of open table shares (table definitions)
sql/sql_db.cc:
safer strxnmov()
sql/sql_delete.cc:
Use new interface to find_temporary_table()
sql/sql_derived.cc:
table_name is now a LEX_STRING
sql/sql_handler.cc:
TABLE_SHARE->db and TABLE_SHARE->table_name are now LEX_STRING's
sql/sql_insert.cc:
TABLE_SHARE->db and TABLE_SHARE->table_name are now LEX_STRING's
sql/sql_lex.cc:
Make parsed string a const (to quickly find out if anything is trying to change the query string)
sql/sql_lex.h:
Make parsed string a const (to quickly find out if anything is trying to change the query string)
sql/sql_load.cc:
Safer strxnmov()
sql/sql_parse.cc:
Better error if wrong DB name
sql/sql_partition.cc:
part_info moved to TABLE from TABLE_SHARE
Indentation changes
sql/sql_select.cc:
Indentation fixes
Call field->init(TABLE) for new created fields
Update create_tmp_table() to use TABLE_SHARE properly
sql/sql_select.h:
Call field->init(TABLE) for new created fields
sql/sql_show.cc:
table_name is now a LEX_STRING
part_info moved to TABLE
sql/sql_table.cc:
Use table definition cache to speed up delete of tables
Fixed calls to functions with new interfaces
Don't use 'share_not_to_be_used'
Instead of doing openfrm() when doing repair, we now have to call
get_table_share() followed by open_table_from_share().
Replace some fn_format() with faster unpack_filename().
Safer strxnmov()
part_info is now in TABLE
Added Mikaels patch for partition and ALTER TABLE
Instead of using 'TABLE_SHARE->is_view' use 'table_flags() & HA_NO_COPY_ON_ALTER
sql/sql_test.cc:
table_name and table_cache_key are now LEX_STRING's
sql/sql_trigger.cc:
TABLE_SHARE->db and TABLE_SHARE->table_name are now LEX_STRING's
safer strxnmov()
Removed compiler warnings
sql/sql_update.cc:
Call field->init(TABLE) after field is created
sql/sql_view.cc:
safer strxnmov()
Create common TABLE_SHARE object for views to allow us to cache if table is a view
sql/structs.h:
Added SHOW_TABLE_DEFINITIONS
sql/table.cc:
Creation and destruct of TABLE_SHARE objects that are common for many TABLE objects
The table opening process now works the following way:
- Create common TABLE_SHARE object
- Read the .frm file and unpack it into the TABLE_SHARE object
- Create a TABLE object based on the information in the TABLE_SHARE
object and open a handler to the table object
open_table_def() is written in such a way that it should be trival to add parsing of the .frm files in new formats
sql/table.h:
TABLE objects for the same database table now share a common TABLE_SHARE object
In TABLE_SHARE the most common strings are now LEX_STRING's
sql/unireg.cc:
Changed arguments to rea_create_table() to have same order as other functions
Call field->init(table) for new created fields
sql/unireg.h:
Added OPEN_VIEW
strings/strxnmov.c:
Change strxnmov() to always add end \0
This makes usage of strxnmov() safer as most of MySQL code assumes that strxnmov() will create a null terminated string
