Hello fellow monks

In one of my modules I have two functions and I'm not able to come up with a testcase for the else-branch of one of them.

Here's the code:

[...]
use Carp;
use Scalar::Util        qw(openhandle);
[...]

sub read_value {
    my $input  = shift;
    my $length = shift;

    if (ref $input eq 'SCALAR') {
        return _read_value_from_sref($input, $length);
    }
    elsif (defined openhandle($input)) {
        return _read_value_from_fh($input, $length);
    }
    else {
        croak("Invalid usage!\n");
    }
}

sub _read_value_from_fh {
    my $fh     = shift;
    my $length = shift;

    my $curpos     = tell $fh;
    my $filelength = (stat $fh)[7];
    if ($curpos + $length > $filelength) {
        # can not read beyond end of file
        return;
    }

    if (read $fh, (my $value), $length) {
        return $value;
    }
    # don't know how to provoke the else-branch for testing
    else {
        carp("Something bad happened!\n");

        # try to return to previous position
        seek $fh, 0, $curpos;
        return;
    }
}
[download]

Is the else-branch dead code and can be removed or is there a condition which would be able to reach it? I tried to read beyond EOF, close the file handle, remove read permissions, calling _read_value_from_fh() to directly, feeding a negative length but nothing 'worked'.

bye
thomas