Add my_dup.c

sql/sql_parse.cc:
  cleanup

mysys/my_dup.c

@@ -0,0 +1,40 @@
+/* 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 */

sql/sql_parse.cc

@@ -1087,7 +1087,6 @@ mysql_execute_command(void)
     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,