From c45aba90e8e49a4b931cc52dfefa26332e08a014 Mon Sep 17 00:00:00 2001
From: Alex Pott <alex.a.pott@googlemail.com>
Date: Fri, 31 Dec 2021 16:35:07 +0000
Subject: [PATCH] Issue #2940121 by apaderno, andypost, idebr, Kingdutch,
 kala4ek, mfb, alexpott, Berdir:
 ConfigurableLanguageManager::getLanguageSwitchLinks() doesn't respect what
 LanguageManagerInterface::getLanguageSwitchLinks() says to return

---
 core/lib/Drupal/Core/Language/LanguageManager.php          | 2 +-
 core/lib/Drupal/Core/Language/LanguageManagerInterface.php | 7 +++++--
 core/modules/language/src/ConfigurableLanguageManager.php  | 4 +---
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/core/lib/Drupal/Core/Language/LanguageManager.php b/core/lib/Drupal/Core/Language/LanguageManager.php
index dd1687d56ba..915dac19f6b 100644
--- a/core/lib/Drupal/Core/Language/LanguageManager.php
+++ b/core/lib/Drupal/Core/Language/LanguageManager.php
@@ -215,7 +215,7 @@ class LanguageManager implements LanguageManagerInterface {
    * {@inheritdoc}
    */
   public function getLanguageSwitchLinks($type, Url $url) {
-    return [];
+    return NULL;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Language/LanguageManagerInterface.php b/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
index 9a6b213d645..7f7306d4210 100644
--- a/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
+++ b/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
@@ -171,8 +171,11 @@ interface LanguageManagerInterface {
    * @param \Drupal\Core\Url $url
    *   The URL the switch links will be relative to.
    *
-   * @return array
-   *   A keyed array of links ready to be themed.
+   * @return object|null
+   *   An object with the following keys:
+   *   - links: An array of links indexed by the language ID
+   *   - method_id: The language negotiation method ID
+   *   or NULL if there are no language switch links.
    */
   public function getLanguageSwitchLinks($type, Url $url);
 
diff --git a/core/modules/language/src/ConfigurableLanguageManager.php b/core/modules/language/src/ConfigurableLanguageManager.php
index 143adf604b3..9dd65ff4953 100644
--- a/core/modules/language/src/ConfigurableLanguageManager.php
+++ b/core/modules/language/src/ConfigurableLanguageManager.php
@@ -403,8 +403,6 @@ class ConfigurableLanguageManager extends LanguageManager implements Configurabl
    * {@inheritdoc}
    */
   public function getLanguageSwitchLinks($type, Url $url) {
-    $links = FALSE;
-
     if ($this->negotiator) {
       foreach ($this->negotiator->getNegotiationMethods($type) as $method_id => $method) {
         $reflector = new \ReflectionClass($method['class']);
@@ -422,7 +420,7 @@ class ConfigurableLanguageManager extends LanguageManager implements Configurabl
       }
     }
 
-    return $links;
+    return $links ?? NULL;
   }
 
   /**