From dc3de33a4b03cbbb17acb565ba6826ac42f2d189 Mon Sep 17 00:00:00 2001
From: msquare <msquare@notrademark.de>
Date: Sun, 3 Nov 2019 11:43:13 +0100
Subject: [PATCH] fix #287: handle IDN email addresses

---
 includes/sys_page.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/includes/sys_page.php b/includes/sys_page.php
index e94a92cc..c7b3ec74 100644
--- a/includes/sys_page.php
+++ b/includes/sys_page.php
@@ -220,12 +220,18 @@ function strip_item($item)
 }
 
 /**
- * Überprüft eine E-Mail-Adresse.
+ * Validates an email address with support for IDN domain names.
  *
  * @param string $email
  * @return bool
  */
 function check_email($email)
 {
+    // Convert the domain part from idn to ascii
+    if(substr_count($email, '@') == 1) {
+        list($name, $domain) = explode('@', $email);
+        $domain = idn_to_ascii($domain, IDNA_DEFAULT, INTL_IDNA_VARIANT_UTS46);
+        $email = $name . '@' . $domain;
+    }
     return (bool)filter_var($email, FILTER_VALIDATE_EMAIL);
 }