--- /dev/null
--- /dev/null
++sub eight_dot_three {
++ my ($dir, $base, $ext) = ($_[0] =~ m!^(?:(.+)/)?([^/.]+)(?:\.([^/.]+))?$!);
++ $base = substr($base, 0, 8);
++ $ext = substr($ext, 0, 3) if defined $ext;
++ if (defined $dir) {
++ return ($dir, defined $ext ? "$dir/$base.$ext" : "$dir/$base");
++ } else {
++ return ('.', defined $ext ? "$base.$ext" : $base);
++ }
++}
++
++my %dir;
++
++if (open(MANIFEST, "MANIFEST")) {
++ while (<MANIFEST>) {
++ chomp;
++ s/\s.+//;
++ unless (-f) {
++ warn "$_: missing\n";
++ next;
++ }
++ if (tr/././ > 1) {
++ warn "$_: more than one dot\n";
++ next;
++ }
++ my ($dir, $edt) = eight_dot_three($_);
++ next if $edt eq $_;
++ push @{$dir{$dir}->{$edt}}, $_;
++ }
++} else {
++ die "$0: MANIFEST: $!\n";
++}
++
++for my $dir (sort keys %dir) {
++ for my $edt (keys %{$dir{$dir}}) {
++ my @files = @{$dir{$dir}->{$edt}};
++ if (@files > 1) {
++ print "$dir $edt @files\n";
++ }
++ }
++}