Issue #1572394 by attiks, Sweetchuck: Fixed Language detection by domain only works on port 80.

core/modules/language/language.negotiation.inc

@@ -220,6 +220,11 @@ function language_from_url($languages) {
       break;
 
     case LANGUAGE_NEGOTIATION_URL_DOMAIN:
+      // Get only the host, not the port.
+      $http_host= $_SERVER['HTTP_HOST'];
+      if (strpos($http_host, ':') !== FALSE) {
+        $http_host = current(explode(':', $http_host));
+      }
       $domains = language_negotiation_url_domains();
       foreach ($languages as $language) {
         // Skip the check if the language doesn't have a domain.
@@ -228,7 +233,7 @@ function language_from_url($languages) {
           // the hostname.
           $host = 'http://' . str_replace(array('http://', 'https://'), '', $domains[$language->langcode]);
           $host = parse_url($host, PHP_URL_HOST);
-          if ($_SERVER['HTTP_HOST'] == $host) {
+          if ($http_host == $host) {
             $language_url = $language->langcode;
             break;
           }

core/modules/language/language.test

@@ -706,7 +706,7 @@ class LanguageUILanguageNegotiationTestCase extends WebTestBase {
       array(
         'language_negotiation' => array(LANGUAGE_NEGOTIATION_URL, LANGUAGE_NEGOTIATION_DEFAULT),
         'language_negotiation_url_part' => LANGUAGE_NEGOTIATION_URL_DOMAIN,
-        'language_test_domain' => $language_domain,
+        'language_test_domain' => $language_domain . ':88',
         'path' => 'admin/config',
         'expect' => $language_string,
         'expected_method_id' => LANGUAGE_NEGOTIATION_URL,