Fixed that derived tables are properly droped

mysys/my_init.c:
  Move my_once_free() up to not get warnings for this from safemalloc.
sql/item_row.cc:
  Removed compiler warnings
sql/sql_select.cc:
  split fix_tables_pointer() into two functions to be able to reuse code
sql/sql_select.h:
  split fix_tables_pointer() into two functions to be able to reuse code

1 files changed, 56 insertions, 47 deletions

diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc
index 1ddaedeb480..0a2e2947add 100644
--- a/sql/sql_derived.cc
+++ b/sql/sql_derived.cc
@@ -1,4 +1,4 @@
-/* Copyright (C) 2000 MySQL AB
+/* Copyright (C) 2002-2003 MySQL AB
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
 
 /*
   Derived tables
-  These were introduced by Monty and Sinisa <sinisa@mysql.com>
+  These were introduced by Sinisa <sinisa@mysql.com>
 */
 
 
@@ -38,17 +38,26 @@ static const char *any_db="*any*";	// Special symbol for check_access
     t                   TABLE_LIST for the upper SELECT
 
   IMPLEMENTATION
-  
-  Derived table is  resolved with temporary table. It is created based on the
-  queries defined. After temporary table is created, if this is not EXPLAIN,
-  then the entire unit / node is deleted. unit is deleted if UNION is used 
-  for derived table and node is deleted is it is a  simple SELECT.
+    Derived table is resolved with temporary table. It is created based on the
+    queries defined. After temporary table is created, if this is not EXPLAIN,
+    then the entire unit / node is deleted. unit is deleted if UNION is used 
+    for derived table and node is deleted is it is a  simple SELECT.
+
+    After table creation, the above TABLE_LIST is updated with a new table.
 
-  After table creation, the above TABLE_LIST is updated with a new table.
+    This function is called before any command containing derived table
+    is executed.
 
-  This function is called before any command containing derived table is executed. 
+    Derived tables is stored in thd->derived_tables and freed in
+    close_thread_tables()
 
-  TODO: To move creation of derived tables IN  open_and_lock_tables()
+  TODO
+    Move creation of derived tables in open_and_lock_tables()
+
+  RETURN
+    0	ok
+    1	Error
+    -1	Error and error message given
 */  
 
 
@@ -57,21 +66,21 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
   SELECT_LEX *sl= unit->first_select();
   List<Item> item_list;
   TABLE *table;
-  int res= 0;
+  int res;
   select_union *derived_result;
   TABLE_LIST *tables= (TABLE_LIST *)sl->table_list.first;
   TMP_TABLE_PARAM tmp_table_param;
   bool is_union=sl->next_select() && sl->next_select()->linkage == UNION_TYPE;
-  DBUG_ENTER("mysql_derived");
   SELECT_LEX_NODE *save_current_select= lex->current_select;
+  DBUG_ENTER("mysql_derived");
   
-
-/*
-  In create_total_list, derived tables have to be treated in case of EXPLAIN, 
-  This is because unit/node is not deleted in that case. Current code in this 
-  function has to be improved to recognize better when this function is called 
-  from derived tables and when from other functions.
-*/
+  /*
+    In create_total_list, derived tables have to be treated in case of
+    EXPLAIN, This is because unit/node is not deleted in that
+    case. Current code in this function has to be improved to
+    recognize better when this function is called from derived tables
+    and when from other functions.
+  */
   if (is_union && unit->create_total_list(thd, lex, &tables))
     DBUG_RETURN(-1);
 
@@ -92,30 +101,21 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
   {
     if (is_union)
     {
-/* 
-   The following code is a re-do of fix_tables_pointers() found in sql_select.cc
-   for UNION's within derived tables. The only difference is in navigation, as in 
-   derived tables we care for this level only.
-
-   fix_tables_pointers makes sure that in UNION's we do not open single table twice 
-   if found in different SELECT's.
-
-*/
-      for (SELECT_LEX *sel= sl;
-	   sel;
-	   sel= sel->next_select())
-      {
-	for (TABLE_LIST *cursor= (TABLE_LIST *)sel->table_list.first;
-	     cursor;
-	     cursor=cursor->next)
-	  cursor->table= cursor->table_list->table;
-      }
+      /* 
+	 The following code is a re-do of fix_tables_pointers() found
+	 in sql_select.cc for UNION's within derived tables. The only
+	 difference is in navigation, as in derived tables we care for
+	 this level only.
+
+      */
+      for (SELECT_LEX *sel= sl; sel; sel= sel->next_select())
+	relink_tables(sel);
     }
 
     lex->current_select= sl;
     if (setup_fields(thd,tables,item_list,0,0,1))
     {
-      res=-1;
+      res= -1;
       goto exit;
     }
     bzero((char*) &tmp_table_param,sizeof(tmp_table_param));
@@ -127,7 +127,7 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
 				  TMP_TABLE_ALL_COLUMNS),
                                  HA_POS_ERROR)))
     {
-      res=-1;
+      res= -1;
       goto exit;
     }
   
@@ -142,7 +142,7 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
 	sl->options&= ~OPTION_FOUND_ROWS;
 
       if (is_union)
-	res=mysql_union(thd,lex,derived_result,unit);
+	res= mysql_union(thd,lex,derived_result,unit);
       else
 	res= mysql_select(thd, tables,  sl->item_list,
 			sl->where, (ORDER *) sl->order_list.first,
@@ -153,9 +153,12 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
 
       if (!res)
       {
-// Here we entirely fix both TABLE_LIST and list of SELECT's as there were no derived tables
+	/*
+	  Here we entirely fix both TABLE_LIST and list of SELECT's as
+	  there were no derived tables
+	*/
 	if (derived_result->flush())
-	  res=1;
+	  res= 1;
 	else
 	{
 	  t->real_name=table->real_name;
@@ -164,23 +167,29 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
 	  table->tmp_table=TMP_TABLE;
 	  if (lex->describe)
 	  {
+	    // to fix a problem in EXPLAIN
 	    if (tables)
-	      tables->table_list->table=tables->table; // to fix a problem in EXPLAIN
+	      tables->table_list->table=tables->table;
 	  }
 	  else
 	    unit->exclude();
-	  t->db=(char *)"";
-	  t->derived=(SELECT_LEX *)1; // just in case ...
+	  t->db= (char *)"";
+	  t->derived=(SELECT_LEX *) 1; // just in case ...
 	  table->file->info(HA_STATUS_VARIABLE);
 	}
       }
       delete derived_result;
     }
     if (res)
-      free_tmp_table(thd,table);
+      free_tmp_table(thd, table);
+    else
+    {
+      table->next= thd->derived_tables;
+      thd->derived_tables= table;
+    }
 exit:
     lex->current_select= save_current_select;
-    close_thread_tables(thd);
+    close_thread_tables(thd, 0, 1);
   }
   DBUG_RETURN(res);
 }