Dear Monks, Unicoding is driving me batty today. I'm trying to understand this test output:

Ein <#c3><#96>konomisches Modell
Ein <#d6>konomisches Modell 1
Ein <#d6>konomisches Modell 1

Ein <#c3><#83><#c2><#96>konomisches Modell
Ein <#c3><#96>konomisches Modell
Ein <#c3><#96>konomisches Modell
[download]

Where strings supposedly in perl's internal utf8 show <#d6> in some cases and <#c3><#96> in others. This matters because we use Storable::nfreeze() to store the data, which just copies Perl's internal format. What I expected from the script was the two byte sequence in all cases.

#!/usr/bin/perl -w
no  utf8;
use Encode;

my ($ustring1, $ustring2, $ustring3);

$ustring1 = "Ein Ökonomisches Modell";
$ustring2 = "Ein \326konomisches Modell";
utf8::upgrade($ustring2);
$ustring3 = "Ein \326konomisches Modell";
$ustring3 = decode('latin1',$ustring3, 1);

print "\n";
print print_chrcodes($ustring1)." ".utf8::is_utf8($ustring1)."\n";
print print_chrcodes($ustring2)." ".utf8::is_utf8($ustring2)."\n";
print print_chrcodes($ustring3)." ".utf8::is_utf8($ustring3)."\n";

print "\n";
print print_chrcodes(encode('utf-8-strict',$ustring1))."\n";
print print_chrcodes(encode('utf-8-strict',$ustring2))."\n";
print print_chrcodes(encode('utf-8-strict',$ustring3))."\n";


sub print_chrcodes
{
    my $str = shift;
    my $ret;
    foreach my $ascval (unpack("C*", $str)) {
                if($ascval == 13) {
                        $ret .= '<cr>';
                        next;
                }
                if($ascval == 10) {
                        $ret .= '<nl>';
                        next;
                }
                if($ascval <  128) {
                        $ret .= chr($ascval);
                        next;
                }
        $ret .= sprintf ("<#%x>",$ascval) if($ascval >= 128);
    }
    return $ret;
}
[download]

How can I force the internal perl representation to be two-byte utf-8, so that Storable::nfreeze() output approximates utf-8-strict? Keywords: Unicode, utf-8, utf-8-strict, Perl 5.10, Storable.