From 41e1716d10d748361bc2ef35a6995126f175a182 Mon Sep 17 00:00:00 2001
From: Henry <chocolatkey@gmail.com>
Date: Tue, 15 Oct 2024 01:05:22 -0700
Subject: [PATCH] add punycode normalization for URL

---
 pkg/util/url/url.go      | 6 ++++++
 pkg/util/url/url_test.go | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/pkg/util/url/url.go b/pkg/util/url/url.go
index fb1cb30..a8edad1 100644
--- a/pkg/util/url/url.go
+++ b/pkg/util/url/url.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"github.com/readium/go-toolkit/pkg/internal/extensions"
+	"golang.org/x/net/idna"
 )
 
 /*
@@ -302,6 +303,11 @@ func (u AbsoluteURL) Normalize() URL {
 	}
 
 	u.url.Scheme = SchemeFromString(u.url.Scheme).String()
+	asciiHost, err := idna.ToASCII(u.url.Host)
+	if err == nil {
+		u.url.Host = asciiHost
+	}
+
 	return AbsoluteURL{url: u.url, scheme: Scheme(u.url.Scheme)}
 }
 
diff --git a/pkg/util/url/url_test.go b/pkg/util/url/url_test.go
index bd8be2a..1ed2c20 100644
--- a/pkg/util/url/url_test.go
+++ b/pkg/util/url/url_test.go
@@ -420,6 +420,10 @@ func TestNormalize(t *testing.T) {
 	u, _ := URLFromString("HTTP://example.com/foo")
 	assert.Equal(t, "http://example.com/foo", u.Normalize().String())
 
+	// Host becomes punycode equivalent.
+	u, _ = URLFromString("http://도메인.com/foo")
+	assert.Equal(t, "http://xn--hq1bm8jm9l.com/foo", u.Normalize().String())
+
 	// Percent encoding of path is normalized.
 	u, _ = URLFromString("HTTP://example.com/c'est%20valide")
 	assert.Equal(t, "http://example.com/c'est%20valide", u.Normalize().String())