Merge branch '3.1-stable' into develop

Conflicts resolved:
	system/core/CodeIgniter.php
	system/core/Security.php
	system/database/DB_query_builder.php
	system/libraries/Email.php
	user_guide_src/source/changelog.rst
	user_guide_src/source/conf.py
	user_guide_src/source/installation/downloads.rst
	user_guide_src/source/installation/upgrading.rst

1 files changed, 5 insertions, 1 deletions

diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 1847cc96f..beb2ffa17 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -1824,7 +1824,11 @@ class CI_Email {
 	{
 		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
 		{
-			$email = self::substr($email, 0, ++$atpos).idn_to_ascii(self::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46);
+			list($account, $domain) = explode('@', $email, 2);
+			$domain = defined('INTL_IDNA_VARIANT_UTS46')
+				? idn_to_ascii($domain, 0, INTL_IDNA_VARIANT_UTS46)
+				: idn_to_ascii($domain);
+			$email = $account.'@'.$domain;
 		}
 
 		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));