Subclasses, tied hashes, {get,set}_property, undefined values

[Giuliano <g cioffi tiscali it>]

Dear all,

  I ran into a strange behaviour with Glib::Object::Subclass .
  If I call set_property using a value stored in a tied hash, the
corresponding get_property returns undef. This doesn't happen if 
scalar context is forced when calling set_property.

  Please, see the attached test case.

  If $hashref is a tied hash reference (of course the 'Title'key is
defined):
$w->set_property('title', $hashref->{Title});

  then this returns undef:
$w->set_property('title', $hashref->{Title});

  Whereas the following block returns a defined value:
$w->set_property('title', scalar($hashref->{Title}));
$w->set_property('title', $hashref->{Title});

  Does anyone know why this happens?

thanks for your help,
ciao,
-- 
Giuliano

#!/usr/bin/perl
$i=$j=$r=$b=-16.0;while((print"\n"),$b++<15){foreach$a(0..78){print
+(split //,' .:-;!/>)|&IH%*#')[$k&15];for($i=$k=$r=0;$j=$r*$r-$i*$i
-2+$a/25,$i=2*$r*$i+$b/10,$j*$j+$i*$i<11&&$k++<111;$r=$j){}}}

#!/usr/bin/perl

package ClassFoo;
use strict;
use Gtk2;

use Glib::Object::Subclass
'Gtk2::Bin',
properties => [
Glib::ParamSpec->boxed('title',
    'title',
    'The button\'s title',
    'Glib::Scalar',
    [qw/writable readable/]),
];

sub INIT_INSTANCE {
    my $self = shift;
    $self->{prop_title} = undef;
}

sub SET_PROPERTY {
    my ($self, $pspec, $val) = @_;
    my $propname = $pspec->get_name;
    if ($propname eq 'title') {
        $self->{prop_title} = $val;
    } else {
        die "unknown property ``$propname''";
    }
}

sub GET_PROPERTY {
    my ($self, $pspec) = @_;
    my $propname = $pspec->get_name;
    if ($propname eq 'title') {
        return $self->{prop_title};
    } else {
        die "unknown property ``$propname''";
    }
}


package main;
use strict;
use Hash::Case::Preserve;

my $hashref = {};
tie %$hashref, 'Hash::Case::Preserve';
$hashref->{Title} = 'foo';
my $w;

sub subprint($) { my $a = shift; print "subprint            \"$a\"\n"; }
subprint($hashref->{Title});

$w = new ClassFoo;
$w->set_property('title', $hashref->{Title});
print "get_property        \"".$w->get_property('title')."\"\n";

$w->set_property('title', scalar($hashref->{Title}));
print "get_property scalar \"".$w->get_property('title')."\"\n";

my $hashref_untied = {};
$hashref_untied->{Title} = 'foo';
$w->set_property('title', $hashref_untied->{Title});
print "get_property untied \"".$w->get_property('title')."\"\n";

exit;