Merge spetrunia@bk-internal.mysql.com:/home/bk/mysql-5.1-new

  strxmov(path, share->normalized_path.str, reg_ext, NullS);

  if ((file= my_open(path, O_RDONLY | O_SHARE, MYF(0))) < 0)

  {

    /* Try unecoded 5.0 name */

    uint length;

    strxnmov(path, sizeof(path)-1,

             mysql_data_home, "/", share->db.str, "/",

             share->table_name.str, reg_ext, NullS);

    length= unpack_filename(path, path) - reg_ext_length;

    /*

      The following is a safety test and should never fail

      as the old file name should never be longer than the new one.

    */

    DBUG_ASSERT(length <= share->normalized_path.length);

    /*

      If the old and the new names have the same length,

      then table name does not have tricky characters,

      so no need to check the old file name.

    */

    if (length == share->normalized_path.length ||

        ((file= my_open(path, O_RDONLY | O_SHARE, MYF(0))) < 0))

      goto err_not_open;

    /* Unencoded 5.0 table name found */

    path[length]= '\0'; // Remove .frm extension

    strmov(share->normalized_path.str, path);

    share->normalized_path.length= length;

  }

  error= 4;

  if (my_read(file,(byte*) head, 64, MYF(MY_NABP)))

    goto err;