reverse order in global select list allow to avoid recursion in derived tables

sql/sql_delete.cc

@@ -43,7 +43,7 @@ int mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, ORDER *order,
 
   if ((open_and_lock_tables(thd, table_list)))
     DBUG_RETURN(-1);
-  fix_tables_pointers(&thd->lex.select_lex);
+  fix_tables_pointers(thd->lex.all_selects_list);
   table= table_list->table;
   table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
   thd->proc_info="init";

sql/sql_derived.cc

@@ -50,21 +50,6 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
   if (res)
     DBUG_RETURN(-1);
 
-  for (SELECT_LEX *ssl= sl; ssl; ssl= ssl->next_select_in_list())
-  {
-    TABLE_LIST *t_tables= (TABLE_LIST *)ssl->table_list.first;
-    for (TABLE_LIST *cursor= (TABLE_LIST *)t_tables;
-	 cursor;
-	 cursor=cursor->next)
-    {
-      if (cursor->derived)
-      {
-	res= mysql_derived(thd, lex, (SELECT_LEX_UNIT *)cursor->derived,
-			   cursor);
-	if (res) DBUG_RETURN(res);
-      }
-    }
-  }
   Item *item;
   List_iterator<Item> it(sl->item_list);
 

sql/sql_insert.cc

@@ -157,7 +157,7 @@ int mysql_insert(THD *thd,TABLE_LIST *table_list, List<Item> &fields,
     res= open_and_lock_tables(thd, table_list);
   if (res)
     DBUG_RETURN(-1);
-  fix_tables_pointers(&thd->lex.select_lex);
+  fix_tables_pointers(thd->lex.all_selects_list);
 
   table= table_list->table;
   thd->proc_info="init";

sql/sql_lex.h

@@ -388,6 +388,8 @@ typedef struct st_lex
   SELECT_LEX select_lex;                        /* first SELECT_LEX */
   /* current SELECT_LEX in parsing */
   SELECT_LEX_NODE *current_select;
+  /* list of all SELECT_LEX */
+  SELECT_LEX *all_selects_list;
   uchar *ptr,*tok_start,*tok_end,*end_of_query;
   char *length,*dec,*change,*name;
   char *backup_dir;				/* For RESTORE/BACKUP */

sql/sql_parse.cc

@@ -1316,7 +1316,7 @@ mysql_execute_command(THD *thd)
     that is not a SHOW command or a select that only access local
     variables, but for now this is probably good enough.
   */
-  if (tables || lex->select_lex.next_select_in_list())
+  if (tables || &lex->select_lex != lex->all_selects_list)
     mysql_reset_errors(thd);
   /*
     Save old warning count to be able to send to client how many warnings we
@@ -1353,22 +1353,23 @@ mysql_execute_command(THD *thd)
   */
   if (lex->derived_tables)
   {
-    for (SELECT_LEX *sl= &lex->select_lex; sl; sl= sl->next_select_in_list())
-      if (sl->linkage != DERIVED_TABLE_TYPE)
-	for (TABLE_LIST *cursor= sl->get_table_list();
-	     cursor;
-	     cursor= cursor->next)
-	  if (cursor->derived && (res=mysql_derived(thd, lex,
-						    (SELECT_LEX_UNIT *)
-						    cursor->derived,
-						    cursor)))
-	  {  
-	    if (res < 0 || thd->net.report_error)
-	      send_error(thd,thd->killed ? ER_SERVER_SHUTDOWN : 0);
-	    DBUG_VOID_RETURN;
-	  }
-  } 
-  if ((lex->select_lex.next_select_in_list() && 
+    for (SELECT_LEX *sl= lex->all_selects_list;
+	 sl;
+	 sl= sl->next_select_in_list())
+      for (TABLE_LIST *cursor= sl->get_table_list();
+	   cursor;
+	   cursor= cursor->next)
+	if (cursor->derived && (res=mysql_derived(thd, lex,
+						  (SELECT_LEX_UNIT *)
+						  cursor->derived,
+						  cursor)))
+	{  
+	  if (res < 0 || thd->net.report_error)
+	    send_error(thd,thd->killed ? ER_SERVER_SHUTDOWN : 0);
+	  DBUG_VOID_RETURN;
+	}
+  }
+  if ((&lex->select_lex != lex->all_selects_list && 
        lex->unit.create_total_list(thd, lex, &tables)) ||
       (table_rules_on && tables && thd->slave_thread &&
        !tables_ok(thd,tables)))
@@ -1415,7 +1416,7 @@ mysql_execute_command(THD *thd)
 	}
 	else
 	  thd->send_explain_fields(result);
-	fix_tables_pointers(select_lex);
+	fix_tables_pointers(lex->all_selects_list);
 	res= mysql_explain_union(thd, &thd->lex.unit, result);
 	MYSQL_LOCK *save_lock= thd->lock;
 	thd->lock= (MYSQL_LOCK *)0;
@@ -2841,9 +2842,11 @@ mysql_init_query(THD *thd)
   lex->value_list.empty();
   lex->param_list.empty();
   lex->unit.global_parameters= lex->unit.slave= lex->current_select= 
-    &lex->select_lex;
+    lex->all_selects_list= &lex->select_lex;
   lex->select_lex.master= &lex->unit;
   lex->select_lex.prev= &lex->unit.slave;
+  lex->select_lex.link_next= 0;
+  lex->select_lex.link_prev= (st_select_lex_node**)&(lex->all_selects_list);
   lex->olap=lex->describe=0;
   lex->derived_tables= false;
   thd->check_loops_counter= thd->select_number= 
@@ -2896,8 +2899,7 @@ mysql_new_select(LEX *lex, bool move_down)
     
   select_lex->master_unit()->global_parameters= select_lex;
   DBUG_ASSERT(lex->current_select->linkage != GLOBAL_OPTIONS_TYPE);
-  select_lex->include_global(lex->current_select->select_lex()->
-			     next_select_in_list_addr());
+  select_lex->include_global((st_select_lex_node**)&lex->all_selects_list);
   lex->current_select= select_lex;
   return 0;
 }

sql/sql_select.cc

@@ -158,7 +158,7 @@ int handle_select(THD *thd, LEX *lex, select_result *result)
 {
   int res;
   register SELECT_LEX *select_lex = &lex->select_lex;
-  fix_tables_pointers(select_lex);
+  fix_tables_pointers(lex->all_selects_list);
   if (select_lex->next_select())
     res=mysql_union(thd,lex,result);
   else
@@ -7514,7 +7514,7 @@ int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
   {
     res= mysql_explain_select(thd, sl,
 			      (((&thd->lex.select_lex)==sl)?
-			       ((sl->next_select_in_list())?"PRIMARY":
+			       ((thd->lex.all_selects_list != sl)?"PRIMARY":
 				"SIMPLE"):
 			       ((sl == first)?
 				((sl->linkage == DERIVED_TABLE_TYPE) ?

sql/sql_update.cc

@@ -70,7 +70,7 @@ int mysql_update(THD *thd,
 
   if ((open_and_lock_tables(thd, table_list)))
     DBUG_RETURN(-1);
-  fix_tables_pointers(&thd->lex.select_lex);
+  fix_tables_pointers(thd->lex.all_selects_list);
   table= table_list->table;
 
   save_time_stamp=table->time_stamp;