WWe now store the catalog in Query_log_event in binlog WITHOUT its end zero.

This saves one byte per Query_log_event on disk compared to 5.0.[0..3]. Compatibility problems with 5.0.x where x<4
are explained in the comments in log_event.cc. Putting back s/my_open(O_TRUNC)/(my_delete+my_create) change which had
been wiped away by somebody doing a wrong 4.1->5.0 merge (which happened just
before 5.0.3 :( ). Applying it to new events for LOAD DATA INFILE.
If slave fails in Execute_load_query_log_event::exec_event(),
don't delete the file (so that it's re-usable at next START SLAVE).
And (youpi!) fix for BUG#3247 "a partially completed LOAD DATA INFILE is not
executed at all on the slave" (storing an Execute_load_query_log_event
to binlog, with its error code, instead of Delete_file_log_event).


mysql-test/r/mix_innodb_myisam_binlog.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_change_master.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_deadlock.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_error_ignored_table.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_flush_log_loop.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_loaddata.result:
  we now use one less byte when storing the catalog in binlog so positions change.
  Plus testing replication of LOAD DATA INFILE if duplicate key and non-transactional table.
mysql-test/r/rpl_log.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_max_relay_size.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_relayrotate.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_replicate_do.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_rotate_logs.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/r/rpl_until.result:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/t/mysqlbinlog.test:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/t/mysqlbinlog2.test:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/t/rpl_deadlock.test:
  we now use one less byte when storing the catalog in binlog so positions change
mysql-test/t/rpl_loaddata.test:
  we now use one less byte when storing the catalog in binlog so positions change.
  Plus testing replication of LOAD DATA INFILE if duplicate key and non-transactional table.
mysql-test/t/rpl_until.test:
  we now use one less byte when storing the catalog in binlog so positions change
sql/log_event.cc:
  a) We now store the catalog in Query_log_event in binlog WITHOUT its end zero.
  This saves one byte per Query_log_event on disk. Compatibility problems with 5.0.x where x<4
  are explained in the comments in this file.
  b) putting back s/my_open(O_TRUNC)/(my_delete+my_create) change which had
  been wiped away by somebody doing a wrong 4.1->5.0 merge (which happened just
  before 5.0.3 :( ). Applying it to new events for LOAD DATA INFILE.
  c) if slave fails in Execute_load_query_log_event::exec_event(),
  don't delete the file (so that it's re-usable at next START SLAVE).
sql/log_event.h:
  We now store the catalog in Query_log_event in binlog WITHOUT its end zero.
  This saves one byte per Query_log_event on disk. This new storage for
  the catalog is denoted by Q_CATALOG_NZ_CODE (couldn't re-use Q_CATALOG_CODE
  as 5.0.3 slaves of this 5.0.4 master would segfault because it would
  expect a 0 when there is none.
  Renaming get_open_mode() to get_create_or_append() (see log_event.cc)
sql/sql_load.cc:
  Fix for BUG#3247: if LOAD DATA INFILE fails but has permanently updated a table
  (i.e. has deleted/added/modified some rows in a non-transactional table),
  we must write an Execute_load_query_log_event to binlog (with the error code,
  as this class beautifully inherits from Query_log_event, it can store
  the error code - thanks Dmitri) and not a Delete_file_log_event (we use
  to write a Delete_file_log_event: no update happened on slave, bug).

sql/log_event.h

@@ -234,10 +234,22 @@ struct sql_ex_info
 /* these are codes, not offsets; not more than 256 values (1 byte). */
 #define Q_FLAGS2_CODE           0
 #define Q_SQL_MODE_CODE         1
+/*
+  Q_CATALOG_CODE is catalog with end zero stored; it is used only by MySQL
+  5.0.x where 0<=x<=3.
+*/
 #define Q_CATALOG_CODE          2
 #define Q_AUTO_INCREMENT	3
 #define Q_CHARSET_CODE          4
 #define Q_TIME_ZONE_CODE        5
+/*
+  Q_CATALOG_NZ_CODE is catalog withOUT end zero stored; it is used by MySQL
+  5.0.x where x>=4. Saves one byte in every Query_log_event in binlog,
+  compared to Q_CATALOG_CODE. The reason we didn't simply re-use
+  Q_CATALOG_CODE is that then a 5.0.3 slave of this 5.0.x (x>=4) master would
+  crash (segfault etc) because it would expect a 0 when there is none.
+*/
+#define Q_CATALOG_NZ_CODE       6
 
 /* Intvar event post-header */
 
@@ -1367,7 +1379,7 @@ public:
 #ifdef HAVE_REPLICATION
   int exec_event(struct st_relay_log_info* rli);
   void pack_info(Protocol* protocol);
-  virtual int get_open_mode() const;
+  virtual int get_create_or_append() const;
 #endif /* HAVE_REPLICATION */
 #else
   void print(FILE* file, bool short_form = 0, LAST_EVENT_INFO* last_event_info= 0);
@@ -1475,7 +1487,7 @@ public:
                              bool using_trans);
 #ifdef HAVE_REPLICATION
   Begin_load_query_log_event(THD* thd);
-  int get_open_mode() const;
+  int get_create_or_append() const;
 #endif /* HAVE_REPLICATION */
 #endif
   Begin_load_query_log_event(const char* buf, uint event_len,