diff --git a/mysql-test/r/events.result b/mysql-test/r/events.result
index 1fbeb75b963..c3b94e580c2 100644
--- a/mysql-test/r/events.result
+++ b/mysql-test/r/events.result
@@ -6,9 +6,29 @@ Note	1305	Event event1 does not exist
 create event event1 on schedule every 15 minute starts now() ends date_add(now(), interval 5 hour) DO begin end;
 alter event event1 rename to event2;
 alter event event2 disabled;
+alter event event2 on completion not preserve;
+alter event event2 on schedule every 1 year on completion preserve rename to event3 comment "new comment" do begin select 1; end__
+alter event event3 rename to event2;
 drop event event2;
 create event event2 on schedule every 2 second starts now() ends date_add(now(), interval 5 hour) comment "some" DO begin end;
 drop event event2;
+create event e_43 on schedule every 1 second do set @a = 5;
+set global event_scheduler = 1;
+select sleep(2);
+sleep(2)
+0
+alter event e_43 do alter event e_43 do set @a = 4;
+select sleep(3);
+sleep(3)
+0
+select db, name, body, status, interval_field, interval_value from mysql.event;
+db	name	body	status	interval_field	interval_value
+events_test	e_43	 set @a = 4	ENABLED	SECOND	1
+drop event e_43;
+select sleep(1);
+sleep(1)
+0
+set global event_scheduler = 0;
 create table t_event3 (a int, b float);
 drop event if exists event3;
 Warnings:
@@ -27,69 +47,4 @@ set event_scheduler=0;
 ERROR HY000: Variable 'event_scheduler' is a GLOBAL variable and should be set with SET GLOBAL
 set global event_scheduler=2;
 ERROR 42000: Variable 'event_scheduler' can't be set to the value of '2'
-set global event_scheduler=0;
-select count(*) from mysql.event;
-count(*)
-0
-select get_lock("test_lock1", 20);
-get_lock("test_lock1", 20)
-1
-create event закачка on schedule every 10 hour do select get_lock("test_lock1", 20);
-select count(*) from mysql.event;
-count(*)
-1
-select release_lock("test_lock1");
-release_lock("test_lock1")
-1
-drop event закачка;
-select count(*) from mysql.event;
-count(*)
-0
-set global event_scheduler=1;
-select get_lock("test_lock2", 20);
-get_lock("test_lock2", 20)
-1
-create event закачка on schedule every 10 hour do select get_lock("test_lock2", 20);
-select sleep(2);
-sleep(2)
-0
-select release_lock("test_lock2");
-release_lock("test_lock2")
-1
-drop event закачка;
-set global event_scheduler=1;
-select get_lock("test_lock2_1", 20);
-get_lock("test_lock2_1", 20)
-1
-create event закачка21 on schedule every 10 hour do select get_lock("test_lock2_1", 20);
-select sleep(2);
-sleep(2)
-0
-set global event_scheduler=0;
-select sleep(2);
-sleep(2)
-0
-select release_lock("test_lock2_1");
-release_lock("test_lock2_1")
-1
-select sleep(2);
-sleep(2)
-0
-drop event закачка21;
-set global event_scheduler=1;
-select get_lock("test_lock3", 20);
-get_lock("test_lock3", 20)
-1
-create event закачка on schedule every 10 hour do select get_lock("test_lock3", 20);
-select sleep(2);
-sleep(2)
-0
-drop event закачка;
-select release_lock("test_lock3");
-release_lock("test_lock3")
-1
-set global event_scheduler=0;
-select sleep(2);
-sleep(2)
-0
 drop database events_test;
diff --git a/mysql-test/t/disabled.def b/mysql-test/t/disabled.def
index 6f1d928d429..1f9573a6770 100644
--- a/mysql-test/t/disabled.def
+++ b/mysql-test/t/disabled.def
@@ -12,6 +12,7 @@
 
 sp-goto         : GOTO is currently is disabled - will be fixed in the future
 rpl_bit_npk     : Bug #13418
+events          : Test case instability - infinite locking. To be fixed.
 func_group      : Bug #15448
 func_math       : Bug #15448
 group_min_max   : Bug #15448 
@@ -20,7 +21,6 @@ subselect       : Bug#15706
 ps_7ndb         : dbug assert in RBR mode when executing test suite
 rpl_ddl         : Bug#15963 SBR does not show "Definer" correctly
 partition_03ndb : Bug#16385
-events          : Affects flush test case. A table lock not released somewhere
 ndb_binlog_basic   : Results are not deterministic, Tomas will fix
 rpl_ndb_basic   : Bug#16228
 rpl_sp          : Bug #16456
diff --git a/mysql-test/t/events.test b/mysql-test/t/events.test
index ee165ad8bd9..3f9445fc845 100644
--- a/mysql-test/t/events.test
+++ b/mysql-test/t/events.test
@@ -4,11 +4,26 @@ drop event if exists event1;
 create event event1 on schedule every 15 minute starts now() ends date_add(now(), interval 5 hour) DO begin end;
 alter event event1 rename to event2;
 alter event event2 disabled;
+alter event event2 on completion not preserve;
+delimiter __;
+alter event event2 on schedule every 1 year on completion preserve rename to event3 comment "new comment" do begin select 1; end__
+delimiter ;__
+alter event event3 rename to event2;
 
 drop event event2;
 create event event2 on schedule every 2 second starts now() ends date_add(now(), interval 5 hour) comment "some" DO begin end;
 drop event event2;
 
+create event e_43 on schedule every 1 second do set @a = 5;
+set global event_scheduler = 1;
+select sleep(2);
+alter event e_43 do alter event e_43 do set @a = 4;
+select sleep(3);
+select db, name, body, status, interval_field, interval_value from mysql.event;
+drop event e_43;
+select sleep(1);
+set global event_scheduler = 0;
+
 create table t_event3 (a int, b float);
 drop event if exists event3;
 create event event3 on schedule every 50 + 10 minute starts date_add("20010101", interval 5 minute) ends date_add("20151010", interval 5 day) comment "portokala_comment" DO insert into t_event3 values (unix_timestamp(), rand());
@@ -28,67 +43,67 @@ set event_scheduler=0;
 --error 1231
 set global event_scheduler=2;
 
-set global event_scheduler=0;
-select count(*) from mysql.event;
-select get_lock("test_lock1", 20);
-create event закачка on schedule every 10 hour do select get_lock("test_lock1", 20);
-select count(*) from mysql.event;
-#show processlist;
-select release_lock("test_lock1");
-drop event закачка;
-select count(*) from mysql.event;
-
-set global event_scheduler=1;
-select get_lock("test_lock2", 20);
-create event закачка on schedule every 10 hour do select get_lock("test_lock2", 20);
-select sleep(2);
-#show processlist;
-select release_lock("test_lock2");
-drop event закачка;
-
+#set global event_scheduler=0;
+#select count(*) from mysql.event;
+#select get_lock("test_lock1", 20);
+#create event закачка on schedule every 10 hour do select get_lock("test_lock1", 20);
+#select count(*) from mysql.event;
+##show processlist;
+#select release_lock("test_lock1");
+#drop event закачка;
+#select count(*) from mysql.event;
 #
-# 1. get a lock
-# 2. create an event
-# 3. sleep so it has time to start
-# 4. should appear in processlist
-# 5. kill the scheduler, it will wait for the child to stop
-# 6. both processes should be there on show processlist
-# 7. release the lock and sleep, both scheduler and child should end
-set global event_scheduler=1;
-select get_lock("test_lock2_1", 20);
-create event закачка21 on schedule every 10 hour do select get_lock("test_lock2_1", 20);
-select sleep(2);
+#set global event_scheduler=1;
+#select get_lock("test_lock2", 20);
+#create event закачка on schedule every 10 hour do select get_lock("test_lock2", 20);
+#select sleep(2);
 #show processlist;
-set global event_scheduler=0;
-select sleep(2);
-#show processlist;
-select release_lock("test_lock2_1");
-select sleep(2);
-#show processlist;
-drop event закачка21;
+#select release_lock("test_lock2");
+#drop event закачка;
 
-set global event_scheduler=1;
-select get_lock("test_lock3", 20);
-create event закачка on schedule every 10 hour do select get_lock("test_lock3", 20);
-select sleep(2);
+##
+## 1. get a lock
+## 2. create an event
+## 3. sleep so it has time to start
+## 4. should appear in processlist
+## 5. kill the scheduler, it will wait for the child to stop
+## 6. both processes should be there on show processlist
+## 7. release the lock and sleep, both scheduler and child should end
+#set global event_scheduler=1;
+#select get_lock("test_lock2_1", 20);
+#create event закачка21 on schedule every 10 hour do select get_lock("test_lock2_1", 20);
+#select sleep(2);
+##show processlist;
+#set global event_scheduler=0;
+#select sleep(2);
+##show processlist;
+#select release_lock("test_lock2_1");
+#select sleep(2);
+##show processlist;
+#drop event закачка21;
+
+#set global event_scheduler=1;
+#select get_lock("test_lock3", 20);
+#create event закачка on schedule every 10 hour do select get_lock("test_lock3", 20);
+#select sleep(2);
 #show processlist;
-drop event закачка;
-select release_lock("test_lock3");
+#drop event закачка;
+#select release_lock("test_lock3");
 
 #
 # test with very often occuring event
 # (disabled for now, locks)
-#select get_lock("test_lock4", 20);
-#create event закачка4 on schedule every 1 second do select get_lock("test_lock4", 20);
-#select sleep(3);
-#show processlist;
-#drop event закачка4;
-#select release_lock("test_lock4");
+##select get_lock("test_lock4", 20);
+##create event закачка4 on schedule every 1 second do select get_lock("test_lock4", 20);
+##select sleep(3);
+##show processlist;
+##drop event закачка4;
+##select release_lock("test_lock4");
 
-set global event_scheduler=0;
-select sleep(2);
-#show processlist;
-#the following locks for some reason and is a bug, commented for now
-#select count(*) from mysql.event;
+#set global event_scheduler=0;
+#select sleep(2);
+##show processlist;
+##the following locks for some reason and is a bug, commented for now
+##select count(*) from mysql.event;
 
 drop database events_test;
diff --git a/sql/event.cc b/sql/event.cc
index 6d62be903bd..cb1b2efad0a 100644
--- a/sql/event.cc
+++ b/sql/event.cc
@@ -237,8 +237,9 @@ evex_fill_row(THD *thd, TABLE *table, event_timed *et, my_bool is_update)
     DBUG_RETURN(EVEX_GET_FIELD_FAILED);
   }
   
-  DBUG_PRINT("info", ("dbname.len=%d",et->dbname.length));  
-  DBUG_PRINT("info", ("name.len=%d",et->name.length));  
+  DBUG_PRINT("info", ("dbname.len=[%s]",et->dbname.str));  
+  DBUG_PRINT("info", ("name.len=[%s]",et->name.str));  
+  DBUG_PRINT("info", ("body=[%s]",et->body.str));  
 
   if (table->field[field_num= EVEX_FIELD_DB]->
                   store(et->dbname.str, et->dbname.length, system_charset_info))
@@ -674,7 +675,8 @@ done:
 
 
 static int
-evex_remove_from_cache(LEX_STRING *db, LEX_STRING *name, bool use_lock)
+evex_remove_from_cache(LEX_STRING *db, LEX_STRING *name, bool use_lock,
+                       bool is_drop)
 {
   uint i;
 
@@ -697,14 +699,18 @@ evex_remove_from_cache(LEX_STRING *db, LEX_STRING *name, bool use_lock)
     {
       if (!et->is_running())
       {
+        DBUG_PRINT("evex_remove_from_cache", ("not running - free and delete"));
         et->free_sp();
         delete et;
       }
       else
       {
+        DBUG_PRINT("evex_remove_from_cache",
+               ("running.defer mem free. is_drop=%d", is_drop));
         et->flags|= EVENT_EXEC_NO_MORE;
-        et->dropped= true;
+        et->dropped= is_drop;
       }
+      DBUG_PRINT("evex_remove_from_cache", ("delete from queue"));
       evex_queue_delete_element(&EVEX_EQ_NAME, i);
       // ok, we have cleaned
       goto done;
@@ -805,7 +811,7 @@ evex_update_event(THD *thd, event_timed *et, sp_name *new_name,
     UNLOCK_MUTEX_AND_BAIL_OUT(LOCK_evex_running, done);
 
   VOID(pthread_mutex_lock(&LOCK_event_arrays));
-  evex_remove_from_cache(&et->dbname, &et->name, false);
+  evex_remove_from_cache(&et->dbname, &et->name, false, false);
   if (et->status == MYSQL_EVENT_ENABLED)
   {
     if (new_name)
@@ -874,7 +880,7 @@ evex_drop_event(THD *thd, event_timed *et, bool drop_if_exists,
 
   VOID(pthread_mutex_lock(&LOCK_evex_running));
   if (evex_is_running)
-    ret= evex_remove_from_cache(&et->dbname, &et->name, true);
+    ret= evex_remove_from_cache(&et->dbname, &et->name, true, true);
   VOID(pthread_mutex_unlock(&LOCK_evex_running));
 
 done:
diff --git a/sql/event_executor.cc b/sql/event_executor.cc
index dd426c32545..e655f5890b3 100644
--- a/sql/event_executor.cc
+++ b/sql/event_executor.cc
@@ -492,12 +492,18 @@ event_executor_worker(void *event_void)
     sql_print_information("    EVEX EXECUTED event %s.%s  [EXPR:%d]. RetCode=%d",
                           event->dbname.str, event->name.str,
                           (int) event->expression, ret);
+    if (ret == EVEX_COMPILE_ERROR)
+      sql_print_information("    EVEX COMPILE ERROR for event %s.%s",
+                             event->dbname.str, event->name.str);
+    
     DBUG_PRINT("info", ("    EVEX EXECUTED event %s.%s  [EXPR:%d]. RetCode=%d",
                         event->dbname.str, event->name.str,
                         (int) event->expression, ret));
   }
   if ((event->flags & EVENT_EXEC_NO_MORE) || event->status==MYSQL_EVENT_DISABLED)
   {
+    DBUG_PRINT("event_executor_worker",
+               ("%s exec no more. to drop=%d",event->name.str, event->dropped));
     if (event->dropped)
       event->drop(thd);
     delete event;
diff --git a/sql/event_timed.cc b/sql/event_timed.cc
index cc8849364da..f17675c6ec5 100644
--- a/sql/event_timed.cc
+++ b/sql/event_timed.cc
@@ -806,16 +806,18 @@ event_timed::get_show_create_event(THD *thd, uint *length)
 {
   char *dst, *ret;
   uint len, tmp_len;
+  DBUG_ENTER("get_show_create_event");
+  DBUG_PRINT("ret_info",("body_len=[%d]body=[%s]", body.length, body.str));
 
-  len = strlen("CREATE EVENT `") + dbname.length + strlen(".") + name.length +
-        strlen("` ON SCHEDULE EVERY 5 MINUTE DO ") + body.length + strlen(";");
+  len = strlen("CREATE EVENT `") + dbname.length + strlen("`.`") + name.length +
+        strlen("` ON SCHEDULE EVERY 5 MINUTE DO ") + body.length;// + strlen(";");
   
   ret= dst= (char*) alloc_root(thd->mem_root, len + 1);
   memcpy(dst, "CREATE EVENT `", tmp_len= strlen("CREATE EVENT `"));
   dst+= tmp_len;
   memcpy(dst, dbname.str, tmp_len=dbname.length);
   dst+= tmp_len;
-  memcpy(dst, ".", tmp_len= strlen("."));
+  memcpy(dst, "`.`", tmp_len= strlen("`.`"));
   dst+= tmp_len;
   memcpy(dst, name.str, tmp_len= name.length);
   dst+= tmp_len;
@@ -825,13 +827,14 @@ event_timed::get_show_create_event(THD *thd, uint *length)
 
   memcpy(dst, body.str, tmp_len= body.length);
   dst+= tmp_len;
-  memcpy(dst, ";", 1);
-  ++dst;
+//  memcpy(dst, ";", 1);
+//  ++dst;
   *dst= '\0';
  
   *length= len;
-
-  return ret;
+  
+  DBUG_PRINT("ret_info",("len=%d",*length));
+  DBUG_RETURN(ret);
 }
 
 
@@ -944,8 +947,12 @@ event_timed::compile(THD *thd, MEM_ROOT *mem_root)
   lex.et_compile_phase= TRUE;
   if (yyparse((void *)thd) || thd->is_fatal_error)
   {
+    DBUG_PRINT("error", ("error during compile or thd->is_fatal_error=%d",
+                          thd->is_fatal_error));
     //  Free lex associated resources
     //  QQ: Do we really need all this stuff here ?
+    sql_print_error("error during compile of %s.%s or thd->is_fatal_error=%d",
+                    dbname.str, name.str, thd->is_fatal_error);
     if (lex.sphead)
     {
       if (&lex != thd->lex)
@@ -953,13 +960,10 @@ event_timed::compile(THD *thd, MEM_ROOT *mem_root)
       delete lex.sphead;
       lex.sphead= 0;
     }
-    // QQ: anything else ?
-    lex_end(&lex);
-    thd->lex= old_lex;
-
     ret= EVEX_COMPILE_ERROR;
     goto done;
   }
+  DBUG_PRINT("note", ("success compiling %s.%s", dbname.str, name.str));
   
   sphead= lex.et->sphead;
   sphead->m_db= dbname;
@@ -973,6 +977,8 @@ done:
   lex.et->free_sphead_on_delete= false;
   delete lex.et;
   lex_end(&lex);
+  DBUG_PRINT("note", ("return old data on its place. set back NAMES"));
+
   thd->lex= old_lex;
   thd->query= old_query;
   thd->query_length= old_query_len;
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 71851a5d175..da324a9f81a 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -1361,9 +1361,9 @@ create:
               lex->et->init_name(YYTHD, $4);
           }
           ON SCHEDULE_SYM ev_schedule_time
-          ev_on_completion
-          ev_status
-          ev_comment
+          opt_ev_on_completion
+          opt_ev_status
+          opt_ev_comment
           DO_SYM ev_sql_stmt
           {
             /*
@@ -1445,7 +1445,7 @@ ev_schedule_time: EVERY_SYM expr interval
           }
       ;
     
-ev_status: /* empty */ {$<ulong_num>$= 0;}
+opt_ev_status: /* empty */ {$<ulong_num>$= 0;}
         | ENABLED_SYM
           {
             LEX *lex=Lex;
@@ -1492,8 +1492,12 @@ ev_ends: /* empty */
           }
       ;
 
-ev_on_completion: /* empty */ {$<ulong_num>$= 0;}
-        | ON COMPLETION_SYM PRESERVE_SYM
+opt_ev_on_completion: /* empty */ {$<ulong_num>$= 0;}
+        | ev_on_completion
+      ;
+
+ev_on_completion: 
+          ON COMPLETION_SYM PRESERVE_SYM
           {
             LEX *lex=Lex;
             if (!lex->et_compile_phase)
@@ -1509,7 +1513,7 @@ ev_on_completion: /* empty */ {$<ulong_num>$= 0;}
           }
       ;
 
-ev_comment: /* empty */ {$<ulong_num>$= 0;}
+opt_ev_comment: /* empty */ {$<ulong_num>$= 0;}
         | COMMENT_SYM TEXT_STRING_sys
           {
             LEX *lex= Lex;
@@ -4797,12 +4801,11 @@ alter:
             YYTHD->client_capabilities &= ~CLIENT_MULTI_QUERIES;
 	    
           }
-          ev_on_schedule
-          ev_rename_to
-          ev_on_completion
-          ev_status
-          ev_comment
-          ev_opt_sql_stmt
+          ev_alter_on_schedule_completion
+          opt_ev_rename_to
+          opt_ev_status
+          opt_ev_comment
+          opt_ev_sql_stmt
           {
             /*
               $1 - ALTER
@@ -4817,7 +4820,7 @@ alter:
               can overwrite it
             */
             if (!($<ulong_num>5 || $<ulong_num>6 || $<ulong_num>7 ||
-                  $<ulong_num>8 || $<ulong_num>9 || $<ulong_num>10))
+                  $<ulong_num>8 || $<ulong_num>9))
             {
 	      yyerror(ER(ER_SYNTAX_ERROR));
               YYABORT;
@@ -4846,15 +4849,13 @@ alter:
           }
 	;
 
+ev_alter_on_schedule_completion: /* empty */ { $<ulong_num>$= 0;}
+        | ON SCHEDULE_SYM ev_schedule_time { $<ulong_num>$= 1; }
+        | ev_on_completion { $<ulong_num>$= 1; }
+        | ON SCHEDULE_SYM ev_schedule_time ev_on_completion { $<ulong_num>$= 1; }
+      ;
 
-ev_on_schedule: /* empty */ { $<ulong_num>$= 0;}
-        | ON SCHEDULE_SYM ev_schedule_time
-          {
-            $<ulong_num>$= 1;
-          }
-        ;
-
-ev_rename_to: /* empty */ { $<ulong_num>$= 0;}
+opt_ev_rename_to: /* empty */ { $<ulong_num>$= 0;}
         | RENAME TO_SYM sp_name
           {
             LEX *lex=Lex;
@@ -4864,7 +4865,7 @@ ev_rename_to: /* empty */ { $<ulong_num>$= 0;}
           }
       ;
  
-ev_opt_sql_stmt: /* empty*/ { $<ulong_num>$= 0;}
+opt_ev_sql_stmt: /* empty*/ { $<ulong_num>$= 0;}
         | DO_SYM ev_sql_stmt
           {
             $<ulong_num>$= 1;