unable to upload file using IO::String (or something similar)

[nicolasfranck]

Example:

my $file_store = Catmandu::Store::File::Simple->new(root => "data");
$file_store->index->add({ _id => 1 });
my $dir = $file_store->index->files(1);

my $str = "hello";

#error: "stat() on unopened filehandle GEN0 at [..]File/Copy.pm line 102."
$directory->upload(
  Catmandu::Util::io( \$str ),
  "test.txt"
);

#same error here
$directory->upload(
  IO::String->new($str),
  "test.txt"
);