Fix punycode roundtrip bug (closes #2287)

Author: kraih

Changes

@@ -1,5 +1,6 @@
 
-9.43  2025-10-02
+9.43  2026-02-12
+  - Fixed punycode roundtrip bug in Mojo::Util.
 
 9.42  2025-10-01
   - Un-deprecated the spurt method in Mojo::File, it is now an alternative to spew.

lib/Mojo/Util.pm

@@ -303,7 +303,7 @@ sub punycode_encode {
   my $h = my $basic = length $output;
   $output .= "\x2d" if $basic > 0;
 
-  for my $m (sort grep { $_ >= PC_INITIAL_N } @input) {
+  for my $m (sort { $a <=> $b } grep { $_ >= PC_INITIAL_N } @input) {
     next if $m < $n;
     $delta += ($m - $n) * ($h + 1);
     $n = $m;

t/mojo/util.t

@@ -289,6 +289,11 @@ subtest 'punycode_decode' => sub {
   is punycode_decode('bcher-kva'), 'bücher', 'right punycode decoded result';
 };
 
+subtest 'punycode_decode/punycode_encode roundtrip' => sub {
+  is punycode_decode(punycode_encode('☃⭐️ ')), '☃⭐️ ', 'right punycode roundtrip result';
+  is punycode_decode(punycode_encode('🐳')),    '🐳',    'right punycode roundtrip result';
+};
+
 subtest 'RFC 3492' => sub {
   my @tests = (
     '(A) Arabic (Egyptian):',