On an int==32bits long==64bits system I believe the TreeModel bindings in a couple of places sign extend the GtkTreeIter stamp value but in others zero extend it when making an IV.

I noticed this in cpantesters reports about one of my models where I had foolishly made a stamp potentially >= 0x8000_0000.  The following might exhibit the problem,

use strict;
use warnings;
use Gtk2;

my $stamp = 0x8000_0000;
print "intended stamp $stamp\n";

my $iter = Gtk2::TreeIter->new_from_arrayref ([$stamp,0,undef,undef]);
my $aref = $iter->to_arrayref ($stamp);

print "aref got stamp ", $aref->[0], "\n";


If the stamp is meant to be treated as unsigned (which does seem easiest to me, though it's actually a signed gint) then a cast in sv_from_iter() might be needed [untested],

    av_push (av, newSVuv ((guint) iter->stamp));

and along the same lines probably in the compare done by to_arrayref, to truncate

    if (iter->stamp != (gint) stamp)