limit clause fixed

mysql-test/r/subselect.result

@@ -36,4 +36,8 @@ a	b
 1	7
 2	7
 3	8
+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
+7	2
 drop table t1,t2,t3,t4;

mysql-test/t/subselect.test

@@ -14,7 +14,10 @@ select (select a from t1), a from t2;
 select (select a from t3), a from t2;
 select * from t2 where t2.a=(select a from t1);
 insert into t3 values (6),(7),(3);
-select * from t2 where t2.b=(select a from t3 order by 1 limit 1);
+select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1);
-select * from t2 where t2.b=(select a from t3 order by 1 limit 1) 
+select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
 union (select * from t4 order by a limit 2) limit 3;
+select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
+select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
+(select * from t2 where a>1) as tt;
 drop table t1,t2,t3,t4;

sql/item_subselect.cc

@@ -24,7 +24,6 @@ SUBSELECT TODO:
      (sql_select.h/sql_select.cc)
 
    - add subselect union select (sql_union.cc)
-   - depended from outer select subselects
    
 */
 
@@ -41,6 +40,14 @@ Item_subselect::Item_subselect(THD *thd, st_select_lex *select_lex):
   DBUG_ENTER("Item_subselect::Item_subselect");
   DBUG_PRINT("subs", ("select_lex 0x%xl", (long) select_lex));
   result= new select_subselect(this);
+  SELECT_LEX_UNIT *unit= select_lex->master_unit();
+  unit->offset_limit_cnt= unit->global_parameters->offset_limit;
+  unit->select_limit_cnt= unit->global_parameters->select_limit+
+    select_lex->offset_limit;
+  if (unit->select_limit_cnt < unit->global_parameters->select_limit)
+    unit->select_limit_cnt= HA_POS_ERROR;		// no limit
+  if (unit->select_limit_cnt == HA_POS_ERROR)
+    select_lex->options&= ~OPTION_FOUND_ROWS;
   join= new JOIN(thd, select_lex->item_list, select_lex->options, result);
   this->select_lex= select_lex;
   maybe_null= 1;
@@ -141,9 +148,9 @@ int Item_subselect::exec()
     join->thd->lex.select= select_lex;
     join->exec();
     join->thd->lex.select= save_select;
-    if (!executed)
+    //if (!executed)
       //No rows returned => value is null (returned as inited)
-      executed= 1;
+    //  executed= 1;
     return join->error;
   }
   return 0;

sql/sql_class.cc

@@ -784,9 +784,15 @@ select_subselect::select_subselect(Item_subselect *item)
 
 bool select_subselect::send_data(List<Item> &items)
 {
+  DBUG_ENTER("select_subselect::send_data");
   if (item->executed){
     my_printf_error(ER_SUBSELECT_NO_1_ROW, ER(ER_SUBSELECT_NO_1_ROW), MYF(0));
-    return 1;
+    DBUG_RETURN(1);
+  }
+  if (unit->offset_limit_cnt)
+  {						// using limit offset,count
+    unit->offset_limit_cnt--;
+    DBUG_RETURN(0);
   }
   Item *val_item= (Item *)item->select_lex->item_list.head();
   if ((item->null_value= val_item->is_null()))
@@ -801,5 +807,6 @@ bool select_subselect::send_data(List<Item> &items)
     item->real_value= val_item->val();
     item->res_type= val_item->result_type();
   }
-  return 0;
+  item->executed= 1;
+  DBUG_RETURN(0);
 }

sql/sql_parse.cc

@@ -1275,9 +1275,10 @@ mysql_execute_command(void)
       break;					// Error message is given
     }
 
-    unit->offset_limit_cnt =select_lex->offset_limit;
+    unit->offset_limit_cnt= unit->global_parameters->offset_limit;
-    unit->select_limit_cnt =select_lex->select_limit+select_lex->offset_limit;
+    unit->select_limit_cnt= unit->global_parameters->select_limit+
-    if (unit->select_limit_cnt < select_lex->select_limit)
+      unit->global_parameters->offset_limit;
+    if (unit->select_limit_cnt < unit->global_parameters->select_limit)
       unit->select_limit_cnt= HA_POS_ERROR;		// no limit
     if (unit->select_limit_cnt == HA_POS_ERROR)
       select_lex->options&= ~OPTION_FOUND_ROWS;
@@ -2672,7 +2673,7 @@ mysql_init_query(THD *thd)
   thd->lex.unit.init_select();
   thd->lex.select_lex.init_query();
   thd->lex.unit.slave= &thd->lex.select_lex;
-  thd->lex.unit.select_limit= thd->default_select_limit; //Global limit
+  thd->lex.unit.global_parameters= &thd->lex.select_lex; //Global limit & order
   thd->lex.select_lex.master= &thd->lex.unit;
   thd->lex.select_lex.prev= &thd->lex.unit.slave;
   thd->lex.value_list.empty();