diff --git a/mysql-test/include/handler.inc b/mysql-test/include/handler.inc
index 79e21382d4c..485b2e881d3 100644
--- a/mysql-test/include/handler.inc
+++ b/mysql-test/include/handler.inc
@@ -598,3 +598,97 @@ handler a2 read a last;
 handler a2 read a prev;
 handler a2 close;
 drop table t1;
+
+#
+# Bug#31397 Inconsistent drop table behavior of handler tables.
+#
+
+--disable_warnings
+drop table if exists t1,t2;
+--enable_warnings
+create table t1 (a int);
+handler t1 open as t1_alias;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+flush tables;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+handler t1_alias close;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+handler t1_alias read first;
+drop table t1;
+--error ER_UNKNOWN_TABLE
+handler t1_alias read next;
+
+# Test that temporary tables associated with handlers are properly dropped.
+
+create table t1 (a int);
+create temporary table t2 (a int, key(a));
+handler t1 open as a1;
+handler t2 open as a2;
+handler a2 read a first;
+drop table t1, t2;
+--error ER_UNKNOWN_TABLE
+handler a2 read a next;
+--error ER_UNKNOWN_TABLE
+handler a1 close;
+
+# Alter table drop handlers
+
+create table t1 (a int, key(a));
+create table t2 like t1;
+handler t1 open as a1;
+handler t2 open as a2;
+handler a1 read a first;
+handler a2 read a first;
+alter table t1 add b int;
+--error ER_UNKNOWN_TABLE
+handler a1 close;
+handler a2 close;
+drop table t1, t2;
+
+# Rename table drop handlers
+
+create table t1 (a int, key(a));
+handler t1 open as a1;
+handler a1 read a first;
+rename table t1 to t2;
+--error ER_UNKNOWN_TABLE
+handler a1 read a first;
+drop table t2;
+
+# Optimize table drop handlers
+
+create table t1 (a int, key(a));
+create table t2 like t1;
+handler t1 open as a1;
+handler t2 open as a2;
+handler a1 read a first;
+handler a2 read a first;
+optimize table t1;
+--error ER_UNKNOWN_TABLE
+handler a1 close;
+handler a2 close;
+drop table t1, t2;
+
+# Flush tables causes handlers reopen
+
+create table t1 (a int, b char(1), key a(a), key b(a,b));
+insert into t1 values (0,"a"),(1,"b"),(2,"c"),(3,"d"),(4,"e"),
+                      (5,"f"),(6,"g"),(7,"h"),(8,"i"),(9,"j");
+handler t1 open;
+handler t1 read a first;
+handler t1 read a next;
+flush tables;
+handler t1 read a next;
+handler t1 read a next;
+flush tables with read lock;
+handler t1 read a next;
+unlock tables;
+drop table t1;
+--error ER_UNKNOWN_TABLE
+handler t1 read a next;
diff --git a/mysql-test/r/events_bugs.result b/mysql-test/r/events_bugs.result
index 83609856393..b91e7e88d64 100644
--- a/mysql-test/r/events_bugs.result
+++ b/mysql-test/r/events_bugs.result
@@ -3,6 +3,10 @@ drop database if exists mysqltest_db1;
 drop database if exists mysqltest_db2;
 create database events_test;
 use events_test;
+select * from information_schema.global_variables where variable_name like 'event_scheduler';
+VARIABLE_NAME	VARIABLE_VALUE
+EVENT_SCHEDULER	ON
+SET GLOBAL event_scheduler = 'OFF';
 CREATE EVENT lower_case ON SCHEDULE EVERY 1 MINUTE DO SELECT 1;
 CREATE EVENT Lower_case ON SCHEDULE EVERY 2 MINUTE DO SELECT 2;
 ERROR HY000: Event 'Lower_case' already exists
diff --git a/mysql-test/r/handler_innodb.result b/mysql-test/r/handler_innodb.result
index d9a1a0aa12b..9d269f78d10 100644
--- a/mysql-test/r/handler_innodb.result
+++ b/mysql-test/r/handler_innodb.result
@@ -637,3 +637,94 @@ a	b
 8	i
 handler a2 close;
 drop table t1;
+drop table if exists t1,t2;
+create table t1 (a int);
+handler t1 open as t1_alias;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+flush tables;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+handler t1_alias close;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+handler t1_alias read first;
+a
+drop table t1;
+handler t1_alias read next;
+ERROR 42S02: Unknown table 't1_alias' in HANDLER
+create table t1 (a int);
+create temporary table t2 (a int, key(a));
+handler t1 open as a1;
+handler t2 open as a2;
+handler a2 read a first;
+a
+drop table t1, t2;
+handler a2 read a next;
+ERROR 42S02: Unknown table 'a2' in HANDLER
+handler a1 close;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+create table t1 (a int, key(a));
+create table t2 like t1;
+handler t1 open as a1;
+handler t2 open as a2;
+handler a1 read a first;
+a
+handler a2 read a first;
+a
+alter table t1 add b int;
+handler a1 close;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+handler a2 close;
+drop table t1, t2;
+create table t1 (a int, key(a));
+handler t1 open as a1;
+handler a1 read a first;
+a
+rename table t1 to t2;
+handler a1 read a first;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+drop table t2;
+create table t1 (a int, key(a));
+create table t2 like t1;
+handler t1 open as a1;
+handler t2 open as a2;
+handler a1 read a first;
+a
+handler a2 read a first;
+a
+optimize table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	optimize	status	OK
+handler a1 close;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+handler a2 close;
+drop table t1, t2;
+create table t1 (a int, b char(1), key a(a), key b(a,b));
+insert into t1 values (0,"a"),(1,"b"),(2,"c"),(3,"d"),(4,"e"),
+(5,"f"),(6,"g"),(7,"h"),(8,"i"),(9,"j");
+handler t1 open;
+handler t1 read a first;
+a	b
+0	a
+handler t1 read a next;
+a	b
+1	b
+flush tables;
+handler t1 read a next;
+a	b
+0	a
+handler t1 read a next;
+a	b
+1	b
+flush tables with read lock;
+handler t1 read a next;
+a	b
+0	a
+unlock tables;
+drop table t1;
+handler t1 read a next;
+ERROR 42S02: Unknown table 't1' in HANDLER
diff --git a/mysql-test/r/handler_myisam.result b/mysql-test/r/handler_myisam.result
index b42fdc864fe..0b27b07c4d2 100644
--- a/mysql-test/r/handler_myisam.result
+++ b/mysql-test/r/handler_myisam.result
@@ -637,3 +637,94 @@ a	b
 8	i
 handler a2 close;
 drop table t1;
+drop table if exists t1,t2;
+create table t1 (a int);
+handler t1 open as t1_alias;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+flush tables;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+handler t1_alias close;
+drop table t1;
+create table t1 (a int);
+handler t1 open as t1_alias;
+handler t1_alias read first;
+a
+drop table t1;
+handler t1_alias read next;
+ERROR 42S02: Unknown table 't1_alias' in HANDLER
+create table t1 (a int);
+create temporary table t2 (a int, key(a));
+handler t1 open as a1;
+handler t2 open as a2;
+handler a2 read a first;
+a
+drop table t1, t2;
+handler a2 read a next;
+ERROR 42S02: Unknown table 'a2' in HANDLER
+handler a1 close;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+create table t1 (a int, key(a));
+create table t2 like t1;
+handler t1 open as a1;
+handler t2 open as a2;
+handler a1 read a first;
+a
+handler a2 read a first;
+a
+alter table t1 add b int;
+handler a1 close;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+handler a2 close;
+drop table t1, t2;
+create table t1 (a int, key(a));
+handler t1 open as a1;
+handler a1 read a first;
+a
+rename table t1 to t2;
+handler a1 read a first;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+drop table t2;
+create table t1 (a int, key(a));
+create table t2 like t1;
+handler t1 open as a1;
+handler t2 open as a2;
+handler a1 read a first;
+a
+handler a2 read a first;
+a
+optimize table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	optimize	status	Table is already up to date
+handler a1 close;
+ERROR 42S02: Unknown table 'a1' in HANDLER
+handler a2 close;
+drop table t1, t2;
+create table t1 (a int, b char(1), key a(a), key b(a,b));
+insert into t1 values (0,"a"),(1,"b"),(2,"c"),(3,"d"),(4,"e"),
+(5,"f"),(6,"g"),(7,"h"),(8,"i"),(9,"j");
+handler t1 open;
+handler t1 read a first;
+a	b
+0	a
+handler t1 read a next;
+a	b
+1	b
+flush tables;
+handler t1 read a next;
+a	b
+0	a
+handler t1 read a next;
+a	b
+1	b
+flush tables with read lock;
+handler t1 read a next;
+a	b
+0	a
+unlock tables;
+drop table t1;
+handler t1 read a next;
+ERROR 42S02: Unknown table 't1' in HANDLER
diff --git a/mysql-test/r/kill.result b/mysql-test/r/kill.result
index a08be429a83..3ea5bbd20bc 100644
--- a/mysql-test/r/kill.result
+++ b/mysql-test/r/kill.result
@@ -125,3 +125,14 @@ drop function bug27563;
 drop procedure proc27563;
 PREPARE stmt FROM 'EXPLAIN SELECT * FROM t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13,t14,t15,t16,t17,t18,t19,t20,t21,t22,t23,t24,t25,t26,t27,t28,t29,t30,t31,t32,t33,t34,t35,t36,t37,t38,t39,t40 WHERE a1=a2 AND a2=a3 AND a3=a4 AND a4=a5 AND a5=a6 AND a6=a7 AND a7=a8 AND a8=a9 AND a9=a10 AND a10=a11 AND a11=a12 AND a12=a13 AND a13=a14 AND a14=a15 AND a15=a16 AND a16=a17 AND a17=a18 AND a18=a19 AND a19=a20 AND a20=a21 AND a21=a22 AND a22=a23 AND a23=a24 AND a24=a25 AND a25=a26 AND a26=a27 AND a27=a28 AND a28=a29 AND a29=a30 AND a30=a31 AND a31=a32 AND a32=a33 AND a33=a34 AND a34=a35 AND a35=a36 AND a36=a37 AND a37=a38 AND a38=a39 AND a39=a40  ';
 EXECUTE stmt;
+#
+# Bug#19723: kill of active connection yields different error code
+# depending on platform.
+#
+
+# Connection: con2.
+KILL CONNECTION_ID();
+# CR_SERVER_LOST, CR_SERVER_GONE_ERROR, depending on the timing 
+# of close of the connection socket
+SELECT 1;
+Got one of the listed errors
diff --git a/mysql-test/r/no-threads.result b/mysql-test/r/no-threads.result
index 50e52138be8..aefecd0f7bc 100644
--- a/mysql-test/r/no-threads.result
+++ b/mysql-test/r/no-threads.result
@@ -4,3 +4,6 @@ select 1+1;
 select 1+2;
 1+2
 3
+SHOW GLOBAL VARIABLES LIKE 'thread_handling';
+Variable_name	Value
+thread_handling	no-threads
diff --git a/mysql-test/t/events_bugs-master.opt b/mysql-test/t/events_bugs-master.opt
new file mode 100644
index 00000000000..f93413a61e5
--- /dev/null
+++ b/mysql-test/t/events_bugs-master.opt
@@ -0,0 +1 @@
+--event-scheduler
diff --git a/mysql-test/t/events_bugs.test b/mysql-test/t/events_bugs.test
index ebd86f3a3d2..efdb67349ec 100644
--- a/mysql-test/t/events_bugs.test
+++ b/mysql-test/t/events_bugs.test
@@ -9,6 +9,21 @@ drop database if exists mysqltest_db2;
 create database events_test;
 use events_test;
 
+#
+# START:  Bug #31332 --event-scheduler option misbehaving
+#
+
+# NOTE!! this test must come first! It's testing that the --event-scheduler
+# option with no argument in events_bugs-master.opt turns the scheduler on.
+
+select * from information_schema.global_variables where variable_name like 'event_scheduler';
+
+SET GLOBAL event_scheduler = 'OFF';
+
+#
+# END: Bug #31332
+#
+
 #
 # START - 16415: Events: event names are case sensitive
 #
diff --git a/mysql-test/t/information_schema.test b/mysql-test/t/information_schema.test
index 2dd19a94758..f08d216da27 100644
--- a/mysql-test/t/information_schema.test
+++ b/mysql-test/t/information_schema.test
@@ -1143,6 +1143,7 @@ END$$
 
 DELIMITER ;$$
 
+let $wait_timeout= 300;
 let $wait_condition=select count(*) = 0 from information_schema.events where event_name='event_status';
 --source include/wait_condition.inc
 
diff --git a/mysql-test/t/kill.test b/mysql-test/t/kill.test
index 5d5095f7d61..3da4232502d 100644
--- a/mysql-test/t/kill.test
+++ b/mysql-test/t/kill.test
@@ -304,3 +304,21 @@ while ($i)
   dec $i ;
 }
 --enable_query_log
+
+###########################################################################
+
+--echo #
+--echo # Bug#19723: kill of active connection yields different error code
+--echo # depending on platform.
+--echo #
+
+--echo
+--echo # Connection: con2.
+--connection con2
+
+KILL CONNECTION_ID();
+
+--echo # CR_SERVER_LOST, CR_SERVER_GONE_ERROR, depending on the timing 
+--echo # of close of the connection socket
+--error 2013, 2006 
+SELECT 1;
diff --git a/mysql-test/t/no-threads.test b/mysql-test/t/no-threads.test
index 806cf24e961..31ea6406ee9 100644
--- a/mysql-test/t/no-threads.test
+++ b/mysql-test/t/no-threads.test
@@ -3,3 +3,4 @@
 #
 select 1+1;
 select 1+2;
+SHOW GLOBAL VARIABLES LIKE 'thread_handling';
diff --git a/mysql-test/t/sp_notembedded.test b/mysql-test/t/sp_notembedded.test
index b5037b469ae..4a747b9c614 100644
--- a/mysql-test/t/sp_notembedded.test
+++ b/mysql-test/t/sp_notembedded.test
@@ -45,27 +45,9 @@ call bug4902_2()|
 call bug4902_2()|
 drop procedure bug4902_2|
 
-
-# Disable until bug#17244 is fixed
---disable_parsing
 #
-# BUG#5278: Stored procedure packets out of order if SET PASSWORD.
+# BUG#3583: query cache doesn't work for stored procedures
 #
---disable_warnings
-drop function if exists bug5278|
---enable_warnings
-create function bug5278 () returns char
-begin
-  SET PASSWORD FOR 'bob'@'%.loc.gov' = PASSWORD('newpass');
-  return 'okay';
-end|
-
---error 1133
-select bug5278()|
---error 1133
-select bug5278()|
-drop function bug5278|
---enable_parsing
 
 --disable_warnings
 drop table if exists t1|
@@ -74,9 +56,6 @@ create table t1 (
 	id   char(16) not null default '',
         data int not null
 )|
-#
-# BUG#3583: query cache doesn't work for stored procedures
-#
 --disable_warnings
 drop procedure if exists bug3583|
 --enable_warnings
diff --git a/sql/events.cc b/sql/events.cc
index 262c62bdbc8..73b8f2cda84 100644
--- a/sql/events.cc
+++ b/sql/events.cc
@@ -146,7 +146,7 @@ bool
 Events::set_opt_event_scheduler(char *argument)
 {
   if (argument == NULL)
-    opt_event_scheduler= Events::EVENTS_DISABLED;
+    opt_event_scheduler= Events::EVENTS_ON;
   else
   {
     int type;
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 03c65c9d654..a7624c5bbcd 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -356,10 +356,35 @@ String *Item_func_concat::val_str(String *str)
       }
       else
       {						// Two big const strings
-	if (tmp_value.alloc(max_length) ||
-	    tmp_value.copy(*res) ||
-	    tmp_value.append(*res2))
+        /*
+          NOTE: We should be prudent in the initial allocation unit -- the
+          size of the arguments is a function of data distribution, which
+          can be any. Instead of overcommitting at the first row, we grow
+          the allocated amount by the factor of 2. This ensures that no
+          more than 25% of memory will be overcommitted on average.
+        */
+
+        uint concat_len= res->length() + res2->length();
+
+        if (tmp_value.alloced_length() < concat_len)
+        {
+          if (tmp_value.alloced_length() == 0)
+          {
+            if (tmp_value.alloc(concat_len))
+              goto null;
+          }
+          else
+          {
+            uint new_len = max(tmp_value.alloced_length() * 2, concat_len);
+
+            if (tmp_value.realloc(new_len))
+              goto null;
+          }
+        }
+
+	if (tmp_value.copy(*res) || tmp_value.append(*res2))
 	  goto null;
+
 	res= &tmp_value;
 	use_as_buff=str;
       }
@@ -679,8 +704,33 @@ String *Item_func_concat_ws::val_str(String *str)
     }
     else
     {						// Two big const strings
-      if (tmp_value.alloc(max_length) ||
-	  tmp_value.copy(*res) ||
+      /*
+        NOTE: We should be prudent in the initial allocation unit -- the
+        size of the arguments is a function of data distribution, which can
+        be any. Instead of overcommitting at the first row, we grow the
+        allocated amount by the factor of 2. This ensures that no more than
+        25% of memory will be overcommitted on average.
+      */
+
+      uint concat_len= res->length() + sep_str->length() + res2->length();
+
+      if (tmp_value.alloced_length() < concat_len)
+      {
+        if (tmp_value.alloced_length() == 0)
+        {
+          if (tmp_value.alloc(concat_len))
+            goto null;
+        }
+        else
+        {
+          uint new_len = max(tmp_value.alloced_length() * 2, concat_len);
+
+          if (tmp_value.realloc(new_len))
+            goto null;
+        }
+      }
+
+      if (tmp_value.copy(*res) ||
 	  tmp_value.append(*sep_str) ||
 	  tmp_value.append(*res2))
 	goto null;
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 12838317646..f19e11357cd 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -1289,12 +1289,9 @@ bool mysql_ha_open(THD *thd, TABLE_LIST *tables, bool reopen);
 bool mysql_ha_close(THD *thd, TABLE_LIST *tables);
 bool mysql_ha_read(THD *, TABLE_LIST *,enum enum_ha_read_modes,char *,
                    List<Item> *,enum ha_rkey_function,Item *,ha_rows,ha_rows);
-int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags,
-                   bool is_locked);
-/* mysql_ha_flush mode_flags bits */
-#define MYSQL_HA_CLOSE_FINAL        0x00
-#define MYSQL_HA_REOPEN_ON_USAGE    0x01
-#define MYSQL_HA_FLUSH_ALL          0x02
+void mysql_ha_flush(THD *thd);
+void mysql_ha_rm_tables(THD *thd, TABLE_LIST *tables);
+void mysql_ha_cleanup(THD *thd);
 
 /* sql_base.cc */
 #define TMP_TABLE_KEY_EXTRA 8
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 4cf6e05751f..5da23fd1a7c 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -2596,7 +2596,12 @@ int my_message_sql(uint error, const char *str, myf MyFlags)
     thd->is_slave_error=  1; // needed to catch query errors during replication
 
     if (!thd->no_warnings_for_error)
+    {
+      thd->no_warnings_for_error= TRUE;
       push_warning(thd, MYSQL_ERROR::WARN_LEVEL_ERROR, error, str);
+      thd->no_warnings_for_error= FALSE;
+    }
+
     /*
       thd->lex->current_select == 0 if lex structure is not inited
       (not query command (COM_QUERY))
@@ -4599,8 +4604,13 @@ pthread_handler_t handle_connections_sockets(void *arg __attribute__((unused)))
 			  sock == unix_sock ? VIO_LOCALHOST: 0)) ||
 	my_net_init(&thd->net,vio_tmp))
     {
-      if (vio_tmp)
-	vio_delete(vio_tmp);
+      /*
+        Only delete the temporary vio if we didn't already attach it to the
+        NET object. The destructor in THD will delete any initialized net
+        structure.
+      */
+      if (vio_tmp && thd->net.vio != vio_tmp)
+        vio_delete(vio_tmp);
       else
       {
 	(void) shutdown(new_sock, SHUT_RDWR);
@@ -7745,12 +7755,13 @@ mysqld_get_one_option(int optid,
     break;
   }
   case OPT_ONE_THREAD:
-    global_system_variables.thread_handling= 2;
+    global_system_variables.thread_handling=
+      SCHEDULER_ONE_THREAD_PER_CONNECTION;
     break;
   case OPT_THREAD_HANDLING:
   {
     global_system_variables.thread_handling=
-      find_type_or_exit(argument, &thread_handling_typelib, opt->name);
+      find_type_or_exit(argument, &thread_handling_typelib, opt->name)-1;
     break;
   }
   case OPT_FT_BOOLEAN_SYNTAX:
diff --git a/sql/scheduler.h b/sql/scheduler.h
index 8351cefda4c..46bbd300cbb 100644
--- a/sql/scheduler.h
+++ b/sql/scheduler.h
@@ -40,7 +40,7 @@ public:
 
 enum scheduler_types
 {
-  SCHEDULER_ONE_THREAD_PER_CONNECTION=1,
+  SCHEDULER_ONE_THREAD_PER_CONNECTION=0,
   SCHEDULER_NO_THREADS,
   SCHEDULER_POOL_OF_THREADS
 };
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index c0ea73a6c00..991c885b8a4 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -465,14 +465,16 @@ check_routine_name(LEX_STRING *ident)
  */
 
 void *
-sp_head::operator new(size_t size)
+sp_head::operator new(size_t size) throw()
 {
   DBUG_ENTER("sp_head::operator new");
   MEM_ROOT own_root;
   sp_head *sp;
 
-  init_alloc_root(&own_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
+  init_sql_alloc(&own_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
   sp= (sp_head *) alloc_root(&own_root, size);
+  if (sp == NULL)
+    return NULL;
   sp->main_mem_root= own_root;
   DBUG_PRINT("info", ("mem_root 0x%lx", (ulong) &sp->mem_root));
   DBUG_RETURN(sp);
@@ -483,6 +485,10 @@ sp_head::operator delete(void *ptr, size_t size)
 {
   DBUG_ENTER("sp_head::operator delete");
   MEM_ROOT own_root;
+
+  if (ptr == NULL)
+    DBUG_VOID_RETURN;
+
   sp_head *sp= (sp_head *) ptr;
 
   /* Make a copy of main_mem_root as free_root will free the sp */
@@ -536,6 +542,9 @@ sp_head::init(LEX *lex)
 
   lex->spcont= m_pcont= new sp_pcontext();
 
+  if (!lex->spcont)
+    DBUG_VOID_RETURN;
+
   /*
     Altough trg_table_fields list is used only in triggers we init for all
     types of stored procedures to simplify reset_lex()/restore_lex() code.
@@ -1069,7 +1078,7 @@ sp_head::execute(THD *thd)
     DBUG_RETURN(TRUE);
 
   /* init per-instruction memroot */
-  init_alloc_root(&execute_mem_root, MEM_ROOT_BLOCK_SIZE, 0);
+  init_sql_alloc(&execute_mem_root, MEM_ROOT_BLOCK_SIZE, 0);
 
   DBUG_ASSERT(!(m_flags & IS_INVOKED));
   m_flags|= IS_INVOKED;
@@ -1961,16 +1970,29 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
 }
 
 
-// Reset lex during parsing, before we parse a sub statement.
-void
+/**
+  @brief Reset lex during parsing, before we parse a sub statement.
+
+  @param thd Thread handler.
+
+  @return Error state
+    @retval true An error occurred.
+    @retval false Success.
+*/
+
+bool
 sp_head::reset_lex(THD *thd)
 {
   DBUG_ENTER("sp_head::reset_lex");
   LEX *sublex;
   LEX *oldlex= thd->lex;
 
+  sublex= new (thd->mem_root)st_lex_local;
+  if (sublex == 0)
+    DBUG_RETURN(TRUE);
+
+  thd->lex= sublex;
   (void)m_lex.push_front(oldlex);
-  thd->lex= sublex= new st_lex;
 
   /* Reset most stuff. */
   lex_start(thd);
@@ -1991,7 +2013,7 @@ sp_head::reset_lex(THD *thd)
   sublex->interval_list.empty();
   sublex->type= 0;
 
-  DBUG_VOID_RETURN;
+  DBUG_RETURN(FALSE);
 }
 
 // Restore lex during parsing, after we have parsed a sub statement.
@@ -3856,7 +3878,7 @@ sp_add_to_query_tables(THD *thd, LEX *lex,
 
   if (!(table= (TABLE_LIST *)thd->calloc(sizeof(TABLE_LIST))))
   {
-    my_error(ER_OUTOFMEMORY, MYF(0), sizeof(TABLE_LIST));
+    thd->fatal_error();
     return NULL;
   }
   table->db_length= strlen(db);
diff --git a/sql/sp_head.h b/sql/sp_head.h
index d74170534bd..86a77a434ff 100644
--- a/sql/sp_head.h
+++ b/sql/sp_head.h
@@ -260,10 +260,10 @@ public:
   Security_context m_security_ctx;
 
   static void *
-  operator new(size_t size);
+  operator new(size_t size) throw ();
 
   static void
-  operator delete(void *ptr, size_t size);
+  operator delete(void *ptr, size_t size) throw ();
 
   sp_head();
 
@@ -326,7 +326,7 @@ public:
   }
 
   // Resets lex in 'thd' and keeps a copy of the old one.
-  void
+  bool
   reset_lex(THD *thd);
 
   // Restores lex in 'thd' from our copy, but keeps some status from the
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 6896ccd1b8c..ed2920024b6 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -87,7 +87,6 @@ bool Prelock_error_handler::safely_trapped_errors()
   @defgroup Data_Dictionary Data Dictionary
   @{
 */
-
 TABLE *unused_tables;				/* Used by mysql_test */
 HASH open_cache;				/* Used by mysql_test */
 static HASH table_def_cache;
@@ -929,8 +928,8 @@ bool close_cached_tables(THD *thd, bool if_wait_for_refresh,
     thd->proc_info="Flushing tables";
 
     close_old_data_files(thd,thd->open_tables,1,1);
-    mysql_ha_flush(thd, tables, MYSQL_HA_REOPEN_ON_USAGE | MYSQL_HA_FLUSH_ALL,
-                   TRUE);
+    mysql_ha_flush(thd);
+
     bool found=1;
     /* Wait until all threads has closed all the tables we had locked */
     DBUG_PRINT("info",
@@ -2516,7 +2515,7 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
     deadlock may occur.
   */
   if (thd->handler_tables)
-    mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE, TRUE);
+    mysql_ha_flush(thd);
 
   /*
     Actually try to find the table in the open_cache.
@@ -3136,7 +3135,7 @@ bool wait_for_tables(THD *thd)
   {
     thd->some_tables_deleted=0;
     close_old_data_files(thd,thd->open_tables,0,dropping_tables != 0);
-    mysql_ha_flush(thd, (TABLE_LIST*) NULL, MYSQL_HA_REOPEN_ON_USAGE, TRUE);
+    mysql_ha_flush(thd);
     if (!table_is_used(thd->open_tables,1))
       break;
     (void) pthread_cond_wait(&COND_refresh,&LOCK_open);
@@ -3554,7 +3553,7 @@ int open_tables(THD *thd, TABLE_LIST **start, uint *counter, uint flags)
     temporary mem_root for new .frm parsing.
     TODO: variables for size
   */
-  init_alloc_root(&new_frm_mem, 8024, 8024);
+  init_sql_alloc(&new_frm_mem, 8024, 8024);
 
   thd->current_tablenr= 0;
  restart:
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index bf8413e8627..f59a848a242 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -678,9 +678,7 @@ void THD::cleanup(void)
     lock=locked_tables; locked_tables=0;
     close_thread_tables(this);
   }
-  mysql_ha_flush(this, (TABLE_LIST*) 0,
-                 MYSQL_HA_CLOSE_FINAL | MYSQL_HA_FLUSH_ALL, FALSE);
-  hash_free(&handler_tables_hash);
+  mysql_ha_cleanup(this);
   delete_dynamic(&user_var_events);
   hash_free(&user_vars);
   close_temporary_tables(this);
@@ -818,7 +816,20 @@ void THD::awake(THD::killed_state state_to_set)
     if (!slave_thread)
       thread_scheduler.post_kill_notification(this);
 #ifdef SIGNAL_WITH_VIO_CLOSE
-    close_active_vio();
+    if (this != current_thd)
+    {
+      /*
+        In addition to a signal, let's close the socket of the thread that
+        is being killed. This is to make sure it does not block if the
+        signal is lost. This needs to be done only on platforms where
+        signals are not a reliable interruption mechanism.
+
+        If we're killing ourselves, we know that we're not blocked, so this
+        hack is not used.
+      */
+
+      close_active_vio();
+    }
 #endif    
   }
   if (mysys_var)
diff --git a/sql/sql_handler.cc b/sql/sql_handler.cc
index 19a99f9d12b..31d6b28a73c 100644
--- a/sql/sql_handler.cc
+++ b/sql/sql_handler.cc
@@ -65,9 +65,6 @@
 static enum enum_ha_read_modes rkey_to_rnext[]=
 { RNEXT_SAME, RNEXT, RPREV, RNEXT, RPREV, RNEXT, RPREV, RPREV };
 
-static int mysql_ha_flush_table(THD *thd, TABLE **table_ptr, uint mode_flags);
-
-
 /*
   Get hash key and hash key length.
 
@@ -119,13 +116,15 @@ static void mysql_ha_hash_free(TABLE_LIST *tables)
 
   @param thd Thread identifier.
   @param tables A list of tables with the first entry to close.
+  @param is_locked If LOCK_open is locked.
 
   @note Though this function takes a list of tables, only the first list entry
   will be closed.
-  @note Broadcasts refresh if it closed the table.
+  @note Broadcasts refresh if it closed a table with old version.
 */
 
-static void mysql_ha_close_table(THD *thd, TABLE_LIST *tables)
+static void mysql_ha_close_table(THD *thd, TABLE_LIST *tables,
+                                 bool is_locked)
 {
   TABLE **table_ptr;
 
@@ -143,13 +142,15 @@ static void mysql_ha_close_table(THD *thd, TABLE_LIST *tables)
   if (*table_ptr)
   {
     (*table_ptr)->file->ha_index_or_rnd_end();
-    VOID(pthread_mutex_lock(&LOCK_open));
+    if (! is_locked)
+      VOID(pthread_mutex_lock(&LOCK_open));
     if (close_thread_table(thd, table_ptr))
     {
       /* Tell threads waiting for refresh that something has happened */
       broadcast_refresh();
     }
-    VOID(pthread_mutex_unlock(&LOCK_open));
+    if (! is_locked)
+      VOID(pthread_mutex_unlock(&LOCK_open));
   }
   else if (tables->table)
   {
@@ -305,7 +306,7 @@ err:
   if (hash_tables)
     my_free((char*) hash_tables, MYF(0));
   if (tables->table)
-    mysql_ha_close_table(thd, tables);
+    mysql_ha_close_table(thd, tables, FALSE);
   DBUG_PRINT("exit",("ERROR"));
   DBUG_RETURN(TRUE);
 }
@@ -339,7 +340,7 @@ bool mysql_ha_close(THD *thd, TABLE_LIST *tables)
                                               (uchar*) tables->alias,
                                               strlen(tables->alias) + 1)))
   {
-    mysql_ha_close_table(thd, hash_tables);
+    mysql_ha_close_table(thd, hash_tables, FALSE);
     hash_delete(&thd->handler_tables_hash, (uchar*) hash_tables);
   }
   else
@@ -478,7 +479,7 @@ retry:
 
   if (need_reopen)
   {
-    mysql_ha_close_table(thd, tables);
+    mysql_ha_close_table(thd, tables, FALSE);
     hash_tables->table= NULL;
     /*
       The lock might have been aborted, we need to manually reset
@@ -669,163 +670,131 @@ err0:
 }
 
 
-/*
-  Flush (close) a list of HANDLER tables.
+/**
+  Scan the handler tables hash for matching tables.
 
-  SYNOPSIS
-    mysql_ha_flush()
-    thd                         Thread identifier.
-    tables                      The list of tables to close. If NULL,
-                                close all HANDLER tables [marked as flushed].
-    mode_flags                  MYSQL_HA_CLOSE_FINAL finally close the table.
-                                MYSQL_HA_REOPEN_ON_USAGE mark for reopen.
-                                MYSQL_HA_FLUSH_ALL flush all tables, not only
-                                those marked for flush.
-    is_locked                   If LOCK_open is locked.
+  @param thd Thread identifier.
+  @param tables The list of tables to remove.
 
-  DESCRIPTION
-    The list of HANDLER tables may be NULL, in which case all HANDLER
-    tables are closed (if MYSQL_HA_FLUSH_ALL) is set.
-    If 'tables' is NULL and MYSQL_HA_FLUSH_ALL is not set,
-    all HANDLER tables marked for flush are closed.
-    Broadcasts refresh for every table closed.
-
-  NOTE
-    Since mysql_ha_flush() is called when the base table has to be closed,
-    we compare real table names, not aliases. Hence, database names matter.
-
-  RETURN
-    0  ok
+  @return Pointer to head of linked list (TABLE_LIST::next_local) of matching
+          TABLE_LIST elements from handler_tables_hash. Otherwise, NULL if no
+          table was matched.
 */
 
-int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags,
-                   bool is_locked)
+static TABLE_LIST *mysql_ha_find(THD *thd, TABLE_LIST *tables)
 {
-  TABLE_LIST    *tmp_tables;
-  TABLE         **table_ptr;
-  bool          did_lock= FALSE;
-  DBUG_ENTER("mysql_ha_flush");
-  DBUG_PRINT("enter", ("tables: 0x%lx  mode_flags: 0x%02x",
-                       (long) tables, mode_flags));
+  TABLE_LIST *hash_tables, *head= NULL, *first= tables;
+  DBUG_ENTER("mysql_ha_find");
 
-  if (tables)
+  /* search for all handlers with matching table names */
+  for (uint i= 0; i < thd->handler_tables_hash.records; i++)
   {
-    /* Close all tables in the list. */
-    for (tmp_tables= tables ; tmp_tables; tmp_tables= tmp_tables->next_local)
+    hash_tables= (TABLE_LIST*) hash_element(&thd->handler_tables_hash, i);
+    for (tables= first; tables; tables= tables->next_local)
     {
-      DBUG_PRINT("info-in-tables-list",("'%s'.'%s' as '%s'",
-                                        tmp_tables->db, tmp_tables->table_name,
-                                        tmp_tables->alias));
-      /* Close all currently open handler tables with the same base table. */
-      table_ptr= &(thd->handler_tables);
-      while (*table_ptr)
-      {
-        if ((!*tmp_tables->db ||
-             !my_strcasecmp(&my_charset_latin1, (*table_ptr)->s->db.str,
-                             tmp_tables->db)) &&
-            ! my_strcasecmp(&my_charset_latin1,
-                            (*table_ptr)->s->table_name.str,
-                            tmp_tables->table_name))
-        {
-          DBUG_PRINT("info",("*table_ptr '%s'.'%s' as '%s'",
-                             (*table_ptr)->s->db.str,
-                             (*table_ptr)->s->table_name.str,
-                             (*table_ptr)->alias));
-          /* The first time it is required, lock for close_thread_table(). */
-          if (! did_lock && ! is_locked)
-          {
-            VOID(pthread_mutex_lock(&LOCK_open));
-            did_lock= TRUE;
-          }
-          mysql_ha_flush_table(thd, table_ptr, mode_flags);
-          continue;
-        }
-        table_ptr= &(*table_ptr)->next;
-      }
-      /* end of handler_tables list */
+      if ((! *tables->db ||
+          ! my_strcasecmp(&my_charset_latin1, hash_tables->db, tables->db)) &&
+          ! my_strcasecmp(&my_charset_latin1, hash_tables->table_name,
+                          tables->table_name))
+        break;
     }
-    /* end of flush tables list */
-  }
-  else
-  {
-    /* Close all currently open tables [which are marked for flush]. */
-    table_ptr= &(thd->handler_tables);
-    while (*table_ptr)
+    if (tables)
     {
-      if ((mode_flags & MYSQL_HA_FLUSH_ALL) ||
-          (*table_ptr)->needs_reopen_or_name_lock())
-      {
-        /* The first time it is required, lock for close_thread_table(). */
-        if (! did_lock && ! is_locked)
-        {
-          VOID(pthread_mutex_lock(&LOCK_open));
-          did_lock= TRUE;
-        }
-        mysql_ha_flush_table(thd, table_ptr, mode_flags);
-        continue;
-      }
-      table_ptr= &(*table_ptr)->next;
+      hash_tables->next_local= head;
+      head= hash_tables;
     }
   }
 
-  /* Release the lock if it was taken by this function. */
-  if (did_lock)
-    VOID(pthread_mutex_unlock(&LOCK_open));
-
-  DBUG_RETURN(0);
+  DBUG_RETURN(head);
 }
 
-/*
-  Flush (close) a table.
 
-  SYNOPSIS
-    mysql_ha_flush_table()
-    thd                         Thread identifier.
-    table                       The table to close.
-    mode_flags                  MYSQL_HA_CLOSE_FINAL finally close the table.
-                                MYSQL_HA_REOPEN_ON_USAGE mark for reopen.
+/**
+  Remove matching tables from the HANDLER's hash table.
 
-  DESCRIPTION
-    Broadcasts refresh if it closed the table.
-    The caller must lock LOCK_open.
+  @param thd Thread identifier.
+  @param tables The list of tables to remove.
 
-  RETURN
-    0  ok
+  @note Broadcasts refresh if it closed a table with old version.
 */
 
-static int mysql_ha_flush_table(THD *thd, TABLE **table_ptr, uint mode_flags)
+void mysql_ha_rm_tables(THD *thd, TABLE_LIST *tables)
 {
-  TABLE_LIST    *hash_tables;
-  TABLE         *table= *table_ptr;
-  DBUG_ENTER("mysql_ha_flush_table");
-  DBUG_PRINT("enter",("'%s'.'%s' as '%s'  flags: 0x%02x",
-                      table->s->db.str, table->s->table_name.str,
-                      table->alias, mode_flags));
+  TABLE_LIST *hash_tables, *next;
+  DBUG_ENTER("mysql_ha_rm_tables");
 
-  if ((hash_tables= (TABLE_LIST*) hash_search(&thd->handler_tables_hash,
-                                              (uchar*) table->alias,
-                                              strlen(table->alias) + 1)))
+  safe_mutex_assert_not_owner(&LOCK_open);
+
+  DBUG_ASSERT(tables);
+
+  hash_tables= mysql_ha_find(thd, tables);
+
+  while (hash_tables)
   {
-    if (! (mode_flags & MYSQL_HA_REOPEN_ON_USAGE))
-    {
-      /* This is a final close. Remove from hash. */
-      hash_delete(&thd->handler_tables_hash, (uchar*) hash_tables);
-    }
-    else
+    next= hash_tables->next_local;
+    if (hash_tables->table)
+      mysql_ha_close_table(thd, hash_tables, FALSE);
+    hash_delete(&thd->handler_tables_hash, (uchar*) hash_tables);
+    hash_tables= next;
+  }
+
+  DBUG_VOID_RETURN;
+}
+
+
+/**
+  Flush (close and mark for re-open) all tables that should be should
+  be reopen.
+
+  @param thd Thread identifier.
+
+  @note Broadcasts refresh if it closed a table with old version.
+*/
+
+void mysql_ha_flush(THD *thd)
+{
+  TABLE_LIST *hash_tables;
+  DBUG_ENTER("mysql_ha_flush");
+
+  safe_mutex_assert_owner(&LOCK_open);
+
+  for (uint i= 0; i < thd->handler_tables_hash.records; i++)
+  {
+    hash_tables= (TABLE_LIST*) hash_element(&thd->handler_tables_hash, i);
+    if (hash_tables->table && hash_tables->table->needs_reopen_or_name_lock())
     {
+      mysql_ha_close_table(thd, hash_tables, TRUE);
       /* Mark table as closed, ready for re-open. */
       hash_tables->table= NULL;
     }
-  }    
-
-  safe_mutex_assert_owner(&LOCK_open);
-  (*table_ptr)->file->ha_index_or_rnd_end();
-  safe_mutex_assert_owner(&LOCK_open);
-  if (close_thread_table(thd, table_ptr))
-  {
-    /* Tell threads waiting for refresh that something has happened */
-    broadcast_refresh();
   }
 
-  DBUG_RETURN(0);
+  DBUG_VOID_RETURN;
 }
+
+
+/**
+  Close all HANDLER's tables.
+
+  @param thd Thread identifier.
+
+  @note Broadcasts refresh if it closed a table with old version.
+*/
+
+void mysql_ha_cleanup(THD *thd)
+{
+  TABLE_LIST *hash_tables;
+  DBUG_ENTER("mysql_ha_cleanup");
+
+  for (uint i= 0; i < thd->handler_tables_hash.records; i++)
+  {
+    hash_tables= (TABLE_LIST*) hash_element(&thd->handler_tables_hash, i);
+    if (hash_tables->table)
+      mysql_ha_close_table(thd, hash_tables, FALSE);
+   }
+
+  hash_free(&thd->handler_tables_hash);
+
+  DBUG_VOID_RETURN;
+}
+
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index da0ff94ec96..cdae7449cc7 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -1834,11 +1834,11 @@ typedef struct st_lex : public Query_tables_list
 
 struct st_lex_local: public st_lex
 {
-  static void *operator new(size_t size)
+  static void *operator new(size_t size) throw()
   {
     return sql_alloc(size);
   }
-  static void *operator new(size_t size, MEM_ROOT *mem_root)
+  static void *operator new(size_t size, MEM_ROOT *mem_root) throw()
   {
     return (void*) alloc_root(mem_root, (uint) size);
   }
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index b1b1502f015..9d4d62e57b6 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -2700,7 +2700,7 @@ Prepared_statement::Prepared_statement(THD *thd_arg, Protocol *protocol_arg)
   last_errno(0),
   flags((uint) IS_IN_USE)
 {
-  init_alloc_root(&main_mem_root, thd_arg->variables.query_alloc_block_size,
+  init_sql_alloc(&main_mem_root, thd_arg->variables.query_alloc_block_size,
                   thd_arg->variables.query_prealloc_size);
   *last_error= '\0';
 }
diff --git a/sql/sql_rename.cc b/sql/sql_rename.cc
index 750bcd50479..66d89edc146 100644
--- a/sql/sql_rename.cc
+++ b/sql/sql_rename.cc
@@ -51,6 +51,8 @@ bool mysql_rename_tables(THD *thd, TABLE_LIST *table_list, bool silent)
     DBUG_RETURN(1);
   }
 
+  mysql_ha_rm_tables(thd, table_list);
+
   if (wait_if_global_read_lock(thd,0,1))
     DBUG_RETURN(1);
 
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index bf4a02ae5cc..9d26273e809 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -1521,6 +1521,8 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
       built_query.append("DROP TABLE ");
   }
 
+  mysql_ha_rm_tables(thd, tables);
+
   pthread_mutex_lock(&LOCK_open);
 
   /*
@@ -1562,8 +1564,6 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
     handlerton *table_type;
     enum legacy_db_type frm_db_type;
 
-    mysql_ha_flush(thd, table, MYSQL_HA_CLOSE_FINAL, 1);
-
     error= drop_temporary_table(thd, table);
 
     switch (error) {
@@ -1572,13 +1572,7 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
       tmp_table_deleted= 1;
       continue;
     case -1:
-      // table already in use
-      /*
-        XXX: This branch should never be taken outside of SF, trigger or
-             prelocked mode.
-
-        DBUG_ASSERT(thd->in_sub_stmt);
-      */
+      DBUG_ASSERT(thd->in_sub_stmt);
       error= 1;
       goto err_with_placeholders;
     default:
@@ -4025,7 +4019,8 @@ static bool mysql_admin_table(THD* thd, TABLE_LIST* tables,
                             Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
     DBUG_RETURN(TRUE);
 
-  mysql_ha_flush(thd, tables, MYSQL_HA_CLOSE_FINAL, FALSE);
+  mysql_ha_rm_tables(thd, tables);
+
   for (table= tables; table; table= table->next_local)
   {
     char table_name[NAME_LEN*2+2];
@@ -5766,8 +5761,7 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
   build_table_filename(reg_path, sizeof(reg_path), db, table_name, reg_ext, 0);
   build_table_filename(path, sizeof(path), db, table_name, "", 0);
 
-
-  mysql_ha_flush(thd, table_list, MYSQL_HA_CLOSE_FINAL, FALSE);
+  mysql_ha_rm_tables(thd, table_list);
 
   /* DISCARD/IMPORT TABLESPACE is always alone in an ALTER TABLE */
   if (alter_info->tablespace_op != NO_TABLESPACE_OP)