bug#19402 SQL close to the size of the max_allowed_packet fails on the slave

ver 5.0 and 5.1 refinement.
adding to the MAX_SIZE_LOG_EVENT_STATUS estimation status vars and 
EXECUTE_LOAD_QUERY_EXTRA_HEADER_LEN

sql/log_event.cc

@@ -1212,6 +1212,7 @@ bool Query_log_event::write(IO_CACHE* file)
   
   /* Store length of status variables */
   status_vars_len= (uint) (start-start_of_status);
+  DBUG_ASSERT(status_vars_len <= MAX_SIZE_LOG_EVENT_STATUS);
   int2store(buf + Q_STATUS_VARS_LEN_OFFSET, status_vars_len);
 
   /*

sql/log_event.h

@@ -202,11 +202,21 @@ struct sql_ex_info
 
 /* 
   Max number of possible extra bytes in a replication event compared to a
-  packet (i.e. a query) sent from client to master.
+  packet (i.e. a query) sent from client to master;
+  First, an auxiliary log_event status vars estimation:
 */
-#define MAX_LOG_EVENT_HEADER   (LOG_EVENT_HEADER_LEN + /* write_header */ \
-				QUERY_HEADER_LEN     + /* write_data */   \
-				NAME_LEN + 1)
+#define MAX_SIZE_LOG_EVENT_STATUS (4 /* flags2 */   + \
+                                   8 /* sql mode */ + \
+                                   1 + 1 + 255 /* catalog */ + \
+                                   4 /* autoinc */ + \
+                                   6 /* charset */ + \
+                                   MAX_TIME_ZONE_NAME_LENGTH)
+#define MAX_LOG_EVENT_HEADER   ( /* in order of Query_log_event::write */ \
+  LOG_EVENT_HEADER_LEN + /* write_header */ \
+  QUERY_HEADER_LEN     + /* write_data */   \
+  EXECUTE_LOAD_QUERY_EXTRA_HEADER_LEN + /*write_post_header_for_derived */ \
+  MAX_SIZE_LOG_EVENT_STATUS + /* status */ \
+  NAME_LEN + 1)
 
 /* 
    Event header offsets;