$db->{foo} = { a => 'b' };
my $x = $db->{foo};
my $y = $db->{foo};
ok( $x == $y ); # This is broken in 1.0004 and before, but fixed in SVN.

delete $db->{foo};
is( $x, undef ); # This works
is( $x + 0, 0 ); # This does not