id-utils 3.2d bug and fix

[Cynbe ru Taren]

First, trivially, in the id-utils distro README file,
  <address@hidden>.
should be changed to
  <address@hidden>.

Second, micha <address@hidden> correctly reports

    if looking at mkid --help this should work:

    cd /usr/include
    mkid -o ~/test
    or
    mkid -o $HOME/test  /usr/include

    but this fails with:
    mkid: can't create `/home/micha': Is a directory

    ???? this is wrong, the dest-filename is $HOME/test and it can be created...
    ( /home/micha is my home-dir )

    this works:
    cd ~
    mkid -o test /usr/include

    I'm not sure wether the handling of the -o or -f option is right...

The problem is in mkid.c:assert_writeable () which
incorrectly assumes that dirname() is side-effect free.

Substituting the following version of the subroutine
(which gives dirname() a temporary copy of the filename
to munge, leaving the original string unchanged) fixes
the problem:

    void
    assert_writeable (char const *untouchable_file_name )
    {
      /* Make private copy of untouchable_file_name so */
      /* dirname() side-effects won't escape this fn:  */ 
      char* file_name = MALLOC (char, strlen(untouchable_file_name)+1 );
      strcpy( file_name, untouchable_file_name );
      if (access (file_name, 06) < 0)
        {
          if (errno == ENOENT)
            {
              /* On Linux, at least, dirname() writes */
              /* a nul into its input string:         */
              char const *dir_name = dirname (file_name);
              if (!dir_name || !*dir_name)
                dir_name = ".";
              if (access (dir_name, 06) < 0)
                error (1, errno, _("can't create `%s' in `%s'"),
                       basename (untouchable_file_name), dir_name);
            }
          else
            error (1, errno, _("can't modify `%s'"), file_name);
        }
      free( file_name );
    }

(FWIW, I checked the other source files in the
package, and found no other uses of dirname().)

Thanks to everyone concerned for a great little utility!

Life is Good,

 -- Cynbe