$ perl |od -c
use Encode;
my $c = decode "latin1", "\xe4";
$c = uc $c;
$c = chr (1 + ord $c);     ## further mangling
print encode "latin1", $c;
__END__
0000000 305
0000001
$ perl |od -c
use Encode;
my $c = decode "latin1", "\xe4";
$c = uc $c;
$c = chr (1 + ord $c);
print encode "utf8", $c;   ## <-- change here
__END__
0000000 303 205
0000002