[Bug-tar] tar-wish: -k avoid error messages

[Yotam Medini]

Hello tar maintainer(s),

Currently, when tar is used in extraction mode (-x)
with '-k' | '--keep-old-files' (KEEP_OLD_FILES)
it goes through ( @ extarct.c)


      fd = open (file_name, openflag, mode);
      ....
      if (fd < 0)
        {
          if (maybe_recoverable (file_name, &interdir_made))
              // maybe_recoverable has:
              :  switch (errno)
              :    {
              :      ...
              :      switch (old_files_option)
              :      {
              :        case KEEP_OLD_FILES:
              :          return 0;


            goto again_file;

          open_error (file_name);
          skip_member ();

But then, open_error(.) issues an undesired error message on pre-existing files.
It would be nicer if the check for pre-existing file, would occur 
_before_ trying to open. Something like:


     if (
         (old_files_option == KEEP_OLD_FILES) &&     
         (stat(file_name,&dumbuf) == 0)
        )
     {
        if (verbose_option) { WARN("keeping old %s\n", file_name); }
     }
     else
     {
         fd = open (file_name, openflag, mode);
         ....
     }

regards -- yotam