Fix rpl_events test failure in the runtime tree.

mysql-test/r/rpl_events.result:
  Now ON COMPLETION NOT PRESERVE events are also dropped on the
  slave, since DROP EVENT command that is invoked for all such commands
  gets invoked on the slave.
sql/event_data_objects.cc:
  Fix the failing rpl_events test after the patch for Bug#27733.
  At the time Events::drop_event got invoked inside
  Event_job_data::execute() thd->query pointed to CREATE PROCEDURE
  statement. This statement was written to the binary log
  from inside Events::drop_event (under assumption that this is a
  DROP EVENT statement that needs to be replicated), and caused
  creation of this procedure on the slave (and a subsequent failure
  when a procedure with the same name already exist).
  
  The patch ensures that thd->query points at the right query text
  for DROP EVENT executed when dropping ON COMPLETION NOT PRESERVE 
  events.
sql/event_data_objects.h:
  Update a  declaration.
sql/events.cc:
  Change if () to an assert: thd->query now always points at a valid
  query.

mysql-test/r/rpl_events.result

@@ -34,7 +34,6 @@ id	c	ts
 affected rows: 2
 SELECT db, name, status, originator FROM mysql.event WHERE db = 'test' AND name = 'justonce';
 db	name	status	originator
-test	justonce	SLAVESIDE_DISABLED	1
 DROP EVENT IF EXISTS test.slave_once;
 CREATE EVENT test.slave_once ON SCHEDULE EVERY 5 MINUTE DO 
 INSERT INTO t1(c) VALUES ('from slave_once');
@@ -111,7 +110,6 @@ id	c	ts
 affected rows: 2
 SELECT db, name, status, originator FROM mysql.event WHERE db = 'test' AND name = 'justonce';
 db	name	status	originator
-test	justonce	SLAVESIDE_DISABLED	1
 DROP EVENT IF EXISTS test.slave_once;
 CREATE EVENT test.slave_once ON SCHEDULE EVERY 5 MINUTE DO 
 INSERT INTO t1(c) VALUES ('from slave_once');

sql/event_data_objects.cc

@@ -1792,6 +1792,33 @@ Event_job_data::construct_sp_sql(THD *thd, String *sp_sql)
 }
 
 
+/**
+  Get DROP EVENT statement to binlog the drop of ON COMPLETION NOT
+  PRESERVE event.
+*/
+
+bool
+Event_job_data::construct_drop_event_sql(THD *thd, String *sp_sql)
+{
+  LEX_STRING buffer;
+  const uint STATIC_SQL_LENGTH= 14;
+
+  DBUG_ENTER("Event_job_data::construct_drop_event_sql");
+
+  buffer.length= STATIC_SQL_LENGTH + name.length*2 + dbname.length*2;
+  if (! (buffer.str= (char*) thd->alloc(buffer.length)))
+    DBUG_RETURN(TRUE);
+
+  sp_sql->set(buffer.str, buffer.length, system_charset_info);
+  sp_sql->length(0);
+
+  sp_sql->append(C_STRING_WITH_LEN("DROP EVENT "));
+  append_identifier(thd, sp_sql, dbname.str, dbname.length);
+  sp_sql->append('.');
+  append_identifier(thd, sp_sql, name.str, name.length);
+
+  DBUG_RETURN(thd->is_fatal_error);
+}
 
 /**
   Compiles and executes the event (the underlying sp_head object)
@@ -1804,7 +1831,9 @@ bool
 Event_job_data::execute(THD *thd, bool drop)
 {
   String sp_sql;
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
   Security_context event_sctx, *save_sctx= NULL;
+#endif
   CHARSET_INFO *charset_connection;
   List<Item> empty_item_list;
   bool ret= TRUE;
@@ -1916,14 +1945,25 @@ Event_job_data::execute(THD *thd, bool drop)
 end:
   if (drop && !thd->is_fatal_error)
   {
-    sql_print_information("Event Scheduler: Dropping %s.%s",
-                          (const char *) dbname.str, (const char *) name.str);
     /*
       We must do it here since here we're under the right authentication
       ID of the event definer.
     */
-    if (Events::drop_event(thd, dbname, name, FALSE))
+    sql_print_information("Event Scheduler: Dropping %s.%s",
+                          (const char *) dbname.str, (const char *) name.str);
+    /*
+      Construct a query for the binary log, to ensure the event is dropped
+      on the slave
+    */
+    if (construct_drop_event_sql(thd, &sp_sql))
       ret= 1;
+    else
+    {
+      thd->query= sp_sql.c_ptr_safe();
+      thd->query_length= sp_sql.length();
+      if (Events::drop_event(thd, dbname, name, FALSE))
+        ret= 1;
+    }
   }
   if (thd->lex->sphead)                        /* NULL only if a parse error */
   {

sql/event_data_objects.h

@@ -184,6 +184,8 @@ class Event_job_data : public Event_basic
 private:
   bool
   construct_sp_sql(THD *thd, String *sp_sql);
+  bool
+  construct_drop_event_sql(THD *thd, String *sp_sql);
 
   Event_job_data(const Event_job_data &);       /* Prevent use of these */
   void operator=(Event_job_data &);

sql/events.cc

@@ -424,7 +424,8 @@ Events::create_event(THD *thd, Event_parse_data *parse_data,
       if (event_queue)
         event_queue->create_event(thd, new_element, &created);
       /* Binlog the create event. */
-      if (mysql_bin_log.is_open() && (thd->query_length > 0))
+      DBUG_ASSERT(thd->query && thd->query_length);
+      if (mysql_bin_log.is_open())
       {
         thd->clear_error();
         thd->binlog_query(THD::MYSQL_QUERY_TYPE,
@@ -549,7 +550,8 @@ Events::update_event(THD *thd, Event_parse_data *parse_data,
         event_queue->update_event(thd, parse_data->dbname, parse_data->name,
                                   new_element);
       /* Binlog the alter event. */
-      if (mysql_bin_log.is_open() && (thd->query_length > 0))
+      DBUG_ASSERT(thd->query && thd->query_length);
+      if (mysql_bin_log.is_open())
       {
         thd->clear_error();
         thd->binlog_query(THD::MYSQL_QUERY_TYPE,
@@ -628,7 +630,8 @@ Events::drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name, bool if_exists)
     if (event_queue)
       event_queue->drop_event(thd, dbname, name);
     /* Binlog the drop event. */
-    if (mysql_bin_log.is_open() && (thd->query_length > 0))
+    DBUG_ASSERT(thd->query && thd->query_length);
+    if (mysql_bin_log.is_open())
     {
       thd->clear_error();
       thd->binlog_query(THD::MYSQL_QUERY_TYPE,