Add my_dup.c

/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB

   This library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Library General Public

   License as published by the Free Software Foundation; either

   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public

   License along with this library; if not, write to the Free

   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,

   MA 02111-1307, USA */

#define USES_TYPES

#include "mysys_priv.h"

#include "mysys_err.h"

#include <my_dir.h>

#include <errno.h>

#if defined(MSDOS) || defined(__WIN__) || defined(__EMX__)

#include <share.h>

#endif

	/* Open a file */

File my_dup(File file, myf MyFlags)

{

  File fd;

  char *filename;

  DBUG_ENTER("my_dup");

  DBUG_PRINT("my",("file: %d  MyFlags: %d", MyFlags));

  fd = dup(file);

  filename= (((int) file < MY_NFILE) ?

	     my_file_info[(int) file].name : "Unknown");

  DBUG_RETURN(my_register_filename(fd, filename, FILE_BY_DUP,

				   EE_FILENOTFOUND, MyFlags));

} /* my_open */

    select_result *result;

    if (select_lex->options & SELECT_DESCRIBE)

      lex->exchange=0;

    /* Save a call, as it's very uncomon that we use unions */

    if (tables)

    {

      res=check_table_access(thd,