merge

Docs/world.sql:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_select.cc:
  Auto merged

14 files changed, 336 insertions, 138 deletions

diff --git a/mysql-test/r/heap_btree.result b/mysql-test/r/heap_btree.result
index 0e8a32bd7b7..846a852738b 100644
--- a/mysql-test/r/heap_btree.result
+++ b/mysql-test/r/heap_btree.result
@@ -73,8 +73,8 @@ type=heap;
 insert into t1 values (1,1),(2,2),(1,3),(2,4),(2,5),(2,6);
 select * from t1 where x=1;
 x	y
-1	1
 1	3
+1	1
 select * from t1,t1 as t2 where t1.x=t2.y;
 x	y	x	y
 1	1	1	1
diff --git a/mysql-test/r/select.result b/mysql-test/r/select.result
index 925f754f203..3a15e419fa5 100644
--- a/mysql-test/r/select.result
+++ b/mysql-test/r/select.result
@@ -3266,6 +3266,16 @@ select wss_type from t1 where wss_type =102935229216544093;
 wss_type
 102935229216544093
 drop table t1;
+select 1+2,"aaaa",3.13*2.0 into @a,@b,@c;
+select @a;
+@a
+3
+select @b;
+@b
+aaaa
+select @c;
+@c
+6.26
 create table t1 (a int not null auto_increment primary key);
 insert into t1 values ();
 insert into t1 values ();
diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index c365c2ed434..2dcafe2c9cb 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -54,9 +54,9 @@ explain select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1)
 union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	where used
+2	SUBSELECT	t3	ALL	NULL	NULL	NULL	NULL	3	Using filesort
 3	UNION	t4	ALL	NULL	NULL	NULL	NULL	3	where used; Using filesort
 4	SUBSELECT	t2	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBSELECT	t3	ALL	NULL	NULL	NULL	NULL	3	Using filesort
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 (select a from t3 where a<t2.a*4 order by 1 desc limit 1)	a
 3	1
@@ -163,9 +163,7 @@ UNIQUE KEY `email` (`email`)
 INSERT INTO inscrit (pseudo,email) VALUES ('joce','test');
 INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
-EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce');
+EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	inscrit	const	PRIMARY	PRIMARY	35	const	1	
 4	SUBSELECT	inscrit	const	PRIMARY	PRIMARY	35	const	1	
@@ -183,3 +181,21 @@ joce
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
 Subselect returns more than 1 record
 drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
+drop table if exists searchconthardwarefr3;
+CREATE TABLE `searchconthardwarefr3` (
+`topic` mediumint(8) unsigned NOT NULL default '0',
+`date` date NOT NULL default '0000-00-00',
+`pseudo` varchar(35) character set latin1 NOT NULL default '',
+PRIMARY KEY  (`pseudo`,`date`,`topic`),
+KEY `topic` (`topic`)
+) TYPE=MyISAM ROW_FORMAT=DYNAMIC;
+INSERT INTO searchconthardwarefr3 (topic,date,pseudo) VALUES
+('43506','2002-10-02','joce'),('40143','2002-08-03','joce');
+EXPLAIN SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	searchconthardwarefr3	index	NULL	PRIMARY	41	NULL	2	where used; Using index
+EXPLAIN SELECT (SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY								No tables used
+2	SUBSELECT	searchconthardwarefr3	index	NULL	PRIMARY	41	NULL	2	where used; Using index
+drop table searchconthardwarefr3;
diff --git a/mysql-test/t/select.test b/mysql-test/t/select.test
index 15d44bcd672..34ad496f285 100644
--- a/mysql-test/t/select.test
+++ b/mysql-test/t/select.test
@@ -1751,6 +1751,10 @@ select wss_type from t1 where wss_type ='102935229216544104';
 select wss_type from t1 where wss_type ='102935229216544093';
 select wss_type from t1 where wss_type =102935229216544093;
 drop table t1;
+select 1+2,"aaaa",3.13*2.0 into @a,@b,@c;
+select @a;
+select @b;
+select @c;
 
 #
 # Test of removing redundant braces in the FROM part
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index dbf45262a1e..518ade7fcf7 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -83,9 +83,7 @@ CREATE TABLE `inscrit` (
 INSERT INTO inscrit (pseudo,email) VALUES ('joce','test');
 INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
-EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce');
+EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce');
 -- error 1239
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo,email FROM
 inscrit WHERE pseudo='joce');
@@ -96,4 +94,18 @@ SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo
 -- error 1240
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
 
-drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
\ No newline at end of file
+drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
+
+drop table if exists searchconthardwarefr3;
+CREATE TABLE `searchconthardwarefr3` (
+  `topic` mediumint(8) unsigned NOT NULL default '0',
+  `date` date NOT NULL default '0000-00-00',
+  `pseudo` varchar(35) character set latin1 NOT NULL default '',
+  PRIMARY KEY  (`pseudo`,`date`,`topic`),
+  KEY `topic` (`topic`)
+) TYPE=MyISAM ROW_FORMAT=DYNAMIC;
+INSERT INTO searchconthardwarefr3 (topic,date,pseudo) VALUES
+('43506','2002-10-02','joce'),('40143','2002-08-03','joce');
+EXPLAIN SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03';
+EXPLAIN SELECT (SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03');
+drop table searchconthardwarefr3;
\ No newline at end of file
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 6b8c4fd1f14..d1a3c7e235a 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -392,6 +392,8 @@ int mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &list,COND *conds,
 		 SELECT_LEX_UNIT *unit, SELECT_LEX *select_lex,
 		 bool fake_select_lex);
 void fix_tables_pointers(SELECT_LEX *select_lex);
+int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit,
+			select_result *result);
 int mysql_explain_select(THD *thd, SELECT_LEX *sl, char const *type,
 			 select_result *result);
 int mysql_union(THD *thd, LEX *lex,select_result *result);
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index f778a721f54..083b0ed2543 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -912,3 +912,57 @@ bool select_exists_subselect::send_data(List<Item> &items)
   DBUG_RETURN(0);
 }
 
+
+/***************************************************************************
+** Dump  of select to variables
+***************************************************************************/
+int select_dumpvar::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
+{
+  List_iterator_fast<Item> li(list);
+  List_iterator_fast<LEX_STRING> gl(var_list);
+  Item *item;
+  LEX_STRING *ls;
+  if (var_list.elements != list.elements)
+  {
+    my_error(ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT, MYF(0));
+    return 1;
+  }
+  while ((item=li++))
+  {
+    ls= gl++;
+    Item_func_set_user_var *xx = new Item_func_set_user_var(*ls,item);
+    xx->fix_fields(current_thd,(TABLE_LIST*) current_thd->lex.select_lex.table_list.first,&item);
+    xx->fix_length_and_dec();
+    vars.push_back(xx);
+  }
+  return 0;
+}
+bool select_dumpvar::send_data(List<Item> &items)
+{
+  List_iterator_fast<Item_func_set_user_var> li(vars);
+  Item_func_set_user_var *xx;
+  DBUG_ENTER("send_data");
+
+  if (row_count++) 
+  {
+    my_error(ER_TOO_MANY_ROWS, MYF(0));
+    DBUG_RETURN(1);
+  }
+  while ((xx=li++))
+    xx->update();
+  DBUG_RETURN(0);
+}
+
+bool select_dumpvar::send_eof()
+{
+  if (row_count)
+  {
+    ::send_ok(thd,row_count);
+    return 0;
+  }
+  else
+  {
+    my_error(ER_EMPTY_QUERY,MYF(0));
+    return 1;
+  }
+}
diff --git a/sql/sql_class.h b/sql/sql_class.h
index e9a4109a4c1..7b5a6da8c6b 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -966,3 +966,15 @@ public:
    bool send_eof();
  };
 
+class select_dumpvar :public select_result {
+  ha_rows row_count;
+public:
+  List<LEX_STRING> var_list;
+  List<Item_func_set_user_var> vars;
+  select_dumpvar(void)  { var_list.empty(); vars.empty(); row_count=0;}
+  ~select_dumpvar() {}
+  int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
+  bool send_fields(List<Item> &list, uint flag) {return 0;}
+  bool send_data(List<Item> &items);
+  bool send_eof();
+};
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 46206079084..9f09afc78a6 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -955,6 +955,7 @@ void st_select_lex::init_query()
   table_list.first= 0; 
   table_list.next= (byte**) &table_list.first;
   item_list.empty();
+  join= 0;
 }
 
 void st_select_lex::init_select()
@@ -973,7 +974,6 @@ void st_select_lex::init_select()
   ftfunc_list= &ftfunc_list_alloc;
   linkage= UNSPECIFIED_TYPE;
   depended= having_fix_field= 0;
-  
 }
 
 /*
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index f301e4c8af0..de57e9f77a8 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -334,6 +334,7 @@ typedef struct st_lex
   enum SSL_type ssl_type;			/* defined in violite.h */
   String *wild;
   sql_exchange *exchange;
+  select_result *result;
 
   List<key_part_spec> col_list;
   List<key_part_spec> ref_list;
@@ -377,7 +378,7 @@ typedef struct st_lex
   uint param_count;
   bool drop_primary, drop_if_exists, local_file, olap;
   bool in_comment, ignore_space, verbose, simple_alter;
-  bool derived_tables;
+  bool derived_tables, describe;
   uint slave_thd_opt;
   CHARSET_INFO *charset;
 } LEX;
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 8002684377d..046b5d45b59 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -1335,8 +1335,7 @@ mysql_execute_command(THD *thd)
     TODO: solve problem with depended derived tables in subselects
   */
   if (lex->sql_command == SQLCOM_SELECT && 
-      (select_lex->options & SELECT_DESCRIBE) &&
-      lex->derived_tables)
+      lex->describe && lex->derived_tables)
   {
     if (!(explain_result= new select_send()))
     {
@@ -1404,9 +1403,7 @@ mysql_execute_command(THD *thd)
   switch (lex->sql_command) {
   case SQLCOM_SELECT:
   {
-    select_result *result;
-    if (select_lex->options & SELECT_DESCRIBE)
-      lex->exchange=0;
+    select_result *result=lex->result;
     if (tables)
     {
       res=check_table_access(thd,
@@ -1431,51 +1428,10 @@ mysql_execute_command(THD *thd)
     if (unit->select_limit_cnt == HA_POS_ERROR)
       select_lex->options&= ~OPTION_FOUND_ROWS;
 
-    if (lex->exchange)
-    {
-      if (lex->exchange->dumpfile)
-      {
-	if (!(result=new select_dump(lex->exchange)))
-	{
-	  res= -1;
-	  break;
-	}
-      }
-      else
-      {
-	if (!(result=new select_export(lex->exchange)))
-	{
-	  res= -1;
-	  break;
-	}
-      }
-    }
-    else if (!(result=new select_send()))
-    {
-      res= -1;
-#ifdef DELETE_ITEMS
-      delete select_lex->having;
-      delete select_lex->where;
-#endif
-      break;
-    }
-    else
-    {
-      /*
-	Normal select:
-	Change lock if we are using SELECT HIGH PRIORITY,
-	FOR UPDATE or IN SHARE MODE
-      */
-      TABLE_LIST *table;
-      for (table = tables ; table ; table=table->next)
-	table->lock_type= lex->lock_option;
-    }
-
     if (!(res=open_and_lock_tables(thd,tables)))
     {
-      if (select_lex->options & SELECT_DESCRIBE)
+      if (lex->describe)
       {
-	delete result; // we do not need it for explain
 	if (!explain_result)
 	  if (!(explain_result= new select_send()))
 	  {
@@ -1485,24 +1441,7 @@ mysql_execute_command(THD *thd)
 	  else
 	    thd->send_explain_fields(explain_result);
 	fix_tables_pointers(select_lex);
-	for ( SELECT_LEX *sl= select_lex;
-	     sl && res == 0;
-	     sl= sl->next_select_in_list())
-	{
-	  SELECT_LEX *first= sl->master_unit()->first_select();
-	  res= mysql_explain_select(thd, sl,
-				    ((select_lex==sl)?
-				     ((sl->next_select_in_list())?"PRIMARY":
-				       "SIMPLE"):
-				     ((sl == first)?
-				      ((sl->depended)?"DEPENDENT SUBSELECT":
-				       "SUBSELECT"):
-				      ((sl->depended)?"DEPENDENT UNION":
-				       "UNION"))),
-				    explain_result);
-	}
-	if (res > 0)
-	  res= -res; // mysql_explain_select do not report error
+	res= mysql_explain_union(thd, &thd->lex.unit, explain_result);
 	MYSQL_LOCK *save_lock= thd->lock;
 	thd->lock= (MYSQL_LOCK *)0;
 	explain_result->send_eof();
@@ -1510,12 +1449,33 @@ mysql_execute_command(THD *thd)
       }
       else
       {
+	if (!result)
+	{
+	  if ((result=new select_send()))
+	  {
+	    /*
+	      Normal select:
+	      Change lock if we are using SELECT HIGH PRIORITY,
+	      FOR UPDATE or IN SHARE MODE
+	    */
+	    TABLE_LIST *table;
+	    for (table = tables ; table ; table=table->next)
+	      table->lock_type= lex->lock_option;
+	  }
+	  else
+	  {
+	    res= -1;
+#ifdef DELETE_ITEMS
+	    delete select_lex->having;
+	    delete select_lex->where;
+#endif
+	    break;
+	  }
+	}
 	query_cache_store_query(thd, tables);
 	res=handle_select(thd, lex, result);
       }
     }
-    else
-      delete result;
     break;
   }
   case SQLCOM_DO:
@@ -2946,7 +2906,7 @@ mysql_init_query(THD *thd)
   thd->free_list= 0;
   thd->lex.union_option= 0;
   thd->lex.select= &thd->lex.select_lex;
-  thd->lex.olap=0;
+  thd->lex.olap=thd->lex.describe=0;
   thd->lex.select->olap= UNSPECIFIED_OLAP_TYPE;
   thd->fatal_error= 0;				// Safety
   thd->total_warn_count=0;			// Warnings for this query
@@ -2966,6 +2926,7 @@ mysql_init_select(LEX *lex)
     lex->thd->variables.select_limit;
   select_lex->olap=   UNSPECIFIED_OLAP_TYPE;
   lex->exchange= 0;
+  lex->result= 0;
   lex->proc_list.first= 0;
 }
 
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 84f8f7d180a..6a48f56443c 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -216,7 +216,7 @@ JOIN::prepare(TABLE_LIST *tables_init,
 	      SELECT_LEX_UNIT *unit, bool fake_select_lex)
 {
   DBUG_ENTER("JOIN::prepare");
-  
+
   conds= conds_init;
   order= order_init;
   group_list= group_init;
@@ -351,7 +351,7 @@ int
 JOIN::optimize()
 {
   DBUG_ENTER("JOIN::optimize");
-  
+
 #ifdef HAVE_REF_TO_FIELDS			// Not done yet
   /* Add HAVING to WHERE if possible */
   if (having && !group_list && ! sum_func_count)
@@ -1043,36 +1043,60 @@ mysql_select(THD *thd, TABLE_LIST *tables, List<Item> &fields, COND *conds,
 	     SELECT_LEX_UNIT *unit, SELECT_LEX *select_lex,
 	     bool fake_select_lex)
 {
-  JOIN *join = new JOIN(thd, fields, select_options, result);
-
   DBUG_ENTER("mysql_select");
-  thd->proc_info="init";
-  thd->used_tables=0;                         // Updated by setup_fields
 
-  if (join->prepare(tables, conds, order, group, having, proc_param,
-                  select_lex, unit, fake_select_lex))
+  bool free_join= 1;
+  JOIN *join;
+  if (!fake_select_lex && select_lex->join != 0)
   {
-    DBUG_RETURN(-1);
+    //here is EXPLAIN of subselect or derived table
+    join= select_lex->join;
+    join->result= result;
+    if (!join->procedure && result->prepare(join->fields_list, unit))
+    {
+      DBUG_RETURN(-1);
+    }
+    join->select_options= select_options;
+    free_join= 0;
   }
-  switch (join->optimize()) {
+  else
+  {
+    join= new JOIN(thd, fields, select_options, result);
+    thd->proc_info="init";
+    thd->used_tables=0;                         // Updated by setup_fields
+
+    if (join->prepare(tables, conds, order, group, having, proc_param,
+		      select_lex, unit, fake_select_lex))
+    {
+      DBUG_RETURN(-1);
+    }
+  }
+
+  switch (join->optimize()) 
+  {
   case 1:
     DBUG_RETURN(join->error);
   case -1:
     goto err;
-  }
+  } 
 
-  if (join->global_optimize())
+  if (free_join && join->global_optimize())
     goto err;
 
   join->exec();
 
 err:
-  thd->limit_found_rows = join->send_records;
-  thd->examined_row_count = join->examined_rows;
-  thd->proc_info="end";
-  int error= (fake_select_lex?0:join->cleanup(thd)) || thd->net.report_error;
-  delete join;
-  DBUG_RETURN(error);
+  if (free_join)
+  {
+    thd->limit_found_rows = join->send_records;
+    thd->examined_row_count = join->examined_rows;
+    thd->proc_info="end";
+    int error= (fake_select_lex?0:join->cleanup(thd)) || thd->net.report_error;
+    delete join;
+    DBUG_RETURN(error);
+  }
+  else
+    DBUG_RETURN(0);
 }
 
 /*****************************************************************************
@@ -7411,9 +7435,43 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
 	result->send_error(0,NullS);
     }
   }
+  for (SELECT_LEX_UNIT *unit= join->select_lex->first_inner_unit();
+       unit;
+       unit= unit->next_unit())
+  {
+    if (mysql_explain_union(thd, unit, result))
+      DBUG_VOID_RETURN;
+  }
   DBUG_VOID_RETURN;
 }
 
+int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
+{
+  int res= 0;
+  SELECT_LEX *first= unit->first_select();
+  for (SELECT_LEX *sl= first;
+       sl;
+       sl= sl->next_select())
+  {
+    res= mysql_explain_select(thd, sl,
+			      (((&thd->lex.select_lex)==sl)?
+			       ((sl->next_select_in_list())?"PRIMARY":
+				"SIMPLE"):
+			       ((sl == first)?
+				((sl->depended)?"DEPENDENT SUBSELECT":
+				 "SUBSELECT"):
+				((sl->depended)?"DEPENDENT UNION":
+				 "UNION"))),
+			      result);
+    if (res)
+      break;
+
+  }
+  if (res > 0)
+    res= -res; // mysql_explain_select do not report error
+  return res;
+}
+
 int mysql_explain_select(THD *thd, SELECT_LEX *select_lex, char const *type, 
 			 select_result *result)
 {
diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 01b0eb9e6ec..eaeec2c1e68 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -109,7 +109,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result)
   if (prepared)
     DBUG_RETURN(0);
   prepared= 1;
-    
+  union_result=0;
   describe=(first_select()->options & SELECT_DESCRIBE) ? 1 : 0;
   res= 0;
   found_rows_for_union= false;
@@ -309,10 +309,12 @@ int st_select_lex_unit::exec()
 int st_select_lex_unit::cleanup()
 {
   DBUG_ENTER("st_select_lex_unit::cleanup");
-  delete union_result;
-  free_tmp_table(thd,table);
-  table= 0; // Safety
-  
+  if (union_result)
+  {
+    delete union_result;
+    free_tmp_table(thd,table);
+    table= 0; // Safety
+  }
   List_iterator<JOIN*> j(joins);
   JOIN** join;
   while ((join= j++))
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 1786d1ef93f..4f75716ff56 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -528,7 +528,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 
 %type <lex_str>
 	IDENT TEXT_STRING REAL_NUM FLOAT_NUM NUM LONG_NUM HEX_NUM LEX_HOSTNAME
-	ULONGLONG_NUM field_ident select_alias ident ident_or_text UNDERSCORE_CHARSET
+	ULONGLONG_NUM field_ident select_alias ident ident_or_text  UNDERSCORE_CHARSET
 
 %type <lex_str_ptr>
 	opt_table_alias
@@ -637,7 +637,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 	handler_rkey_function handler_read_or_scan
 	single_multi table_wild_list table_wild_one opt_wild union union_list
 	precision union_option opt_on_delete_item subselect_start opt_and
-	subselect_end
+	subselect_end select_var_list select_var_list_init
 END_OF_INPUT
 
 %type <NONE>
@@ -759,7 +759,8 @@ master_def:
        RELAY_LOG_POS_SYM EQ ULONG_NUM
        {
 	 Lex->mi.relay_log_pos = $3;
-       };
+       }
+       ;
 
 
 /* create a table */
@@ -824,11 +825,13 @@ create:
 	    LEX *lex=Lex;
 	    lex->udf.returns=(Item_result) $7;
 	    lex->udf.dl=$9.str;
-	  };
+	  }
+          ;
 
 create2:
 	'(' field_list ')' opt_create_table_options create3 {}
-	| opt_create_table_options create3 {};
+	| opt_create_table_options create3 {}
+        ;
 
 create3:
 	/* empty */ {}
@@ -838,7 +841,8 @@ create3:
 	    lex->lock_option= (using_update_log) ? TL_READ_NO_INSERT : TL_READ;
 	    mysql_init_select(lex);
           }
-          select_options select_item_list opt_select_from union {};
+          select_options select_item_list opt_select_from union {}
+          ;
 
 opt_as:
 	/* empty */ {}
@@ -1549,6 +1553,7 @@ select_part2:
 select_into:
 	limit_clause {}
 	| select_from
+        | opt_into
 	| opt_into select_from
 	| select_from opt_into;
 
@@ -2293,11 +2298,11 @@ select_part3:
 	  mysql_init_select(lex);
 	  lex->select->linkage= DERIVED_TABLE_TYPE;
 	}
-        select_options select_item_list select_intoto
+        select_options select_item_list select_intoto;
 
 select_intoto:
 	limit_clause {}
-	| select_from
+	| select_from;
 
 opt_outer:
 	/* empty */	{}
@@ -2548,20 +2553,61 @@ procedure_item:
 	      YYABORT;
 	    if (!$2->name)
 	      $2->set_name($1,(uint) ((char*) Lex->tok_end - $1));
-	  };
+	  }
+          ;
+
+
+select_var_list_init:
+	   {
+             LEX *lex=Lex;
+	     if (!lex->describe && (!(lex->result= new select_dumpvar())))
+	        YYABORT;
+	   }
+	   select_var_list 
+           ;
+
+select_var_list:
+	   select_var_list ',' select_var_ident
+	   | select_var_ident {}
+           ;
+
+select_var_ident:  '@' ident_or_text
+           {
+             LEX *lex=Lex;
+	     if (lex->result && ((select_dumpvar *)lex->result)->var_list.push_back((LEX_STRING*) sql_memdup(&$2,sizeof(LEX_STRING))))
+	       YYABORT;
+	   }
+           ;
 
 opt_into:
-	INTO OUTFILE TEXT_STRING
+        INTO OUTFILE TEXT_STRING
 	{
-	  if (!(Lex->exchange= new sql_exchange($3.str,0)))
-	    YYABORT;
+	  LEX *lex=Lex;
+	  if (!lex->describe)
+	  {
+	    if (!(lex->exchange= new sql_exchange($3.str,0)))
+	      YYABORT;
+	    if (!(lex->result= new select_export(lex->exchange)))
+	      YYABORT;
+	  }
 	}
 	opt_field_term opt_line_term
 	| INTO DUMPFILE TEXT_STRING
 	{
-	  if (!(Lex->exchange= new sql_exchange($3.str,1)))
-	    YYABORT;
-	};
+	  LEX *lex=Lex;
+	  if (!lex->describe)
+	  {
+	    if (!(lex->exchange= new sql_exchange($3.str,1)))
+	      YYABORT;
+	    if (!(lex->result= new select_dump(lex->exchange)))
+	      YYABORT;
+	  }
+	}
+        | INTO select_var_list_init
+	{
+	  current_thd->safe_to_cache_query=0;
+	}
+        ;
 
 /*
   DO statement
@@ -3025,7 +3071,11 @@ describe:
 	}
 	opt_describe_column
 	| describe_command select
-          { Lex->select_lex.options|= SELECT_DESCRIBE; };
+          { 
+	    LEX *lex=Lex;
+	    lex->select_lex.options|= SELECT_DESCRIBE; 
+	    lex->describe=1;
+	  };
 
 
 describe_command:
@@ -3231,7 +3281,7 @@ param_marker:
             yyerror("You have an error in your SQL syntax");
             YYABORT;
           }
-        }
+        };
 literal:
 	text_literal	{ $$ =	$1; }
 	| NUM		{ $$ =	new Item_int($1.str, (longlong) atol($1.str),$1.length); }
@@ -3582,7 +3632,7 @@ internal_variable_name:
 	    YYABORT;
 	  $$=tmp;
 	}
-	;
+        ;
 
 isolation_types:
 	READ_SYM UNCOMMITTED_SYM	{ $$= ISO_READ_UNCOMMITTED; }
@@ -3603,7 +3653,8 @@ text_or_password:
 	      make_scrambled_password(buff,$3.str);
 	      $$=buff;
 	    }
-	  };
+	  }
+          ;
 
 
 set_expr_or_default:
@@ -3633,16 +3684,19 @@ table_lock_list:
 
 table_lock:
 	table_ident opt_table_alias lock_option
-	{ if (!add_table_to_list($1,$2,0,(thr_lock_type) $3)) YYABORT; };
+	{ if (!add_table_to_list($1,$2,0,(thr_lock_type) $3)) YYABORT; }
+        ;
 
 lock_option:
 	READ_SYM	{ $$=TL_READ_NO_INSERT; }
 	| WRITE_SYM     { $$=current_thd->update_lock_default; }
 	| LOW_PRIORITY WRITE_SYM { $$=TL_WRITE_LOW_PRIORITY; }
-	| READ_SYM LOCAL_SYM { $$= TL_READ; };
+	| READ_SYM LOCAL_SYM { $$= TL_READ; }
+        ;
 
 unlock:
-	UNLOCK_SYM table_or_tables { Lex->sql_command=SQLCOM_UNLOCK_TABLES; };
+	UNLOCK_SYM table_or_tables { Lex->sql_command=SQLCOM_UNLOCK_TABLES; }
+        ;
 
 
 /*
@@ -3672,15 +3726,18 @@ handler:
 	  if (!add_table_to_list($2,0,0))
 	    YYABORT;
         }
-        handler_read_or_scan where_clause limit_clause { };
+        handler_read_or_scan where_clause limit_clause { }
+        ;
 
 handler_read_or_scan:
 	handler_scan_function         { Lex->backup_dir= 0; }
-        | ident handler_rkey_function { Lex->backup_dir= $1.str; };
+        | ident handler_rkey_function { Lex->backup_dir= $1.str; }
+        ;
 
 handler_scan_function:
 	FIRST_SYM  { Lex->ha_read_mode = RFIRST; }
-	| NEXT_SYM { Lex->ha_read_mode = RNEXT;  };
+	| NEXT_SYM { Lex->ha_read_mode = RNEXT;  }
+        ;
 
 handler_rkey_function:
 	FIRST_SYM  { Lex->ha_read_mode = RFIRST; }
@@ -3694,14 +3751,16 @@ handler_rkey_function:
 	  lex->ha_rkey_mode=$1;
 	  if (!(lex->insert_list = new List_item))
 	    YYABORT;
-	} '(' values ')' { };
+	} '(' values ')' { }
+        ;
 
 handler_rkey_mode:
 	  EQ     { $$=HA_READ_KEY_EXACT;   }
 	| GE     { $$=HA_READ_KEY_OR_NEXT; }
 	| LE     { $$=HA_READ_KEY_OR_PREV; }
 	| GT_SYM { $$=HA_READ_AFTER_KEY;   }
-	| LT     { $$=HA_READ_BEFORE_KEY;  };
+	| LT     { $$=HA_READ_BEFORE_KEY;  }
+        ;
 
 /* GRANT / REVOKE */
 
@@ -3739,7 +3798,8 @@ grant:
 grant_privileges:
 	grant_privilege_list {}
 	| ALL PRIVILEGES	{ Lex->grant = GLOBAL_ACLS;}
-	| ALL			{ Lex->grant = GLOBAL_ACLS;};
+	| ALL			{ Lex->grant = GLOBAL_ACLS;}
+        ;
 
 grant_privilege_list:
 	grant_privilege
@@ -3858,7 +3918,8 @@ opt_table:
 	      YYABORT;
 	    if (lex->grant == GLOBAL_ACLS)
 	      lex->grant =  TABLE_ACLS & ~GRANT_ACL;
-	  };
+	  }
+          ;
 
 
 user_list:
@@ -3889,7 +3950,8 @@ grant_user:
 	| user IDENTIFIED_SYM BY PASSWORD TEXT_STRING
 	  { $$=$1; $1->password=$5 ; }
 	| user
-	  { $$=$1; $1->password.str=NullS; };
+	  { $$=$1; $1->password.str=NullS; }
+        ;
 
 
 opt_column_list:
@@ -3922,7 +3984,8 @@ column_list_id:
 	    point->rights |= lex->which_columns;
 	  else
 	    lex->columns.push_back(new LEX_COLUMN (*new_str,lex->which_columns));
-	};
+	}
+        ;
 
 
 require_clause: /* empty */
@@ -3942,7 +4005,7 @@ require_clause: /* empty */
 	  {
 	    Lex->ssl_type=SSL_TYPE_NONE;
 	  }
-	;
+          ;
 
 grant_options:
 	/* empty */ {}
@@ -3950,7 +4013,8 @@ grant_options:
 
 grant_option_list:
 	grant_option_list grant_option {}
-	| grant_option {};
+	| grant_option {}
+        ;
 
 grant_option:
 	GRANT OPTION { Lex->grant |= GRANT_ACL;}
@@ -3968,14 +4032,16 @@ grant_option:
         {
 	  Lex->mqh.connections=$2;
 	  Lex->mqh.bits |= 4;
-	};
+	}
+        ;
 
 begin:
 	BEGIN_SYM   { Lex->sql_command = SQLCOM_BEGIN;} opt_work;
 
 opt_work:
 	/* empty */ {}
-	| WORK_SYM {;};
+	| WORK_SYM {;}
+        ;
 
 commit:
 	COMMIT_SYM   { Lex->sql_command = SQLCOM_COMMIT;};
@@ -4085,4 +4151,4 @@ subselect_end:
 	{
 	  LEX *lex=Lex;
 	  lex->select = lex->select->outer_select();
-	}
+	};