[5.2] Languagefilter: Add message when no content language is published

[joomlapl-bot]

PR w związku ze zmianą oryginału joomla/joomla-cms#43232 Poniżej zmiany w oryginale:

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diff --git a/administrator/language/en-GB/plg_system_languagefilter.ini b/administrator/language/en-GB/plg_system_languagefilter.ini
index e23fed35d4ec6..1ef0ade87b738 100644
--- a/administrator/language/en-GB/plg_system_languagefilter.ini
+++ b/administrator/language/en-GB/plg_system_languagefilter.ini
@@ -5,6 +5,7 @@
 
 PLG_SYSTEM_LANGUAGEFILTER="System - Language Filter"
 PLG_SYSTEM_LANGUAGEFILTER_BROWSER_SETTINGS="Browser Settings"
+PLG_SYSTEM_LANGUAGEFILTER_ERROR_NO_CONTENT_LANGUAGE="You have no content language published, but have enabled the Language Filter plugin. This will result in numerous errors!"
 PLG_SYSTEM_LANGUAGEFILTER_FIELD_ALTERNATE_META_LABEL="Add Alternate Meta Tags"
 PLG_SYSTEM_LANGUAGEFILTER_FIELD_AUTOMATIC_CHANGE_LABEL="Automatic Language Change"
 PLG_SYSTEM_LANGUAGEFILTER_FIELD_COOKIE_LABEL="Cookie Lifetime"
diff --git a/plugins/system/languagefilter/src/Extension/LanguageFilter.php b/plugins/system/languagefilter/src/Extension/LanguageFilter.php
index bd49c509e0d2e..d1dbaa5a29a4f 100644
--- a/plugins/system/languagefilter/src/Extension/LanguageFilter.php
+++ b/plugins/system/languagefilter/src/Extension/LanguageFilter.php
@@ -22,6 +22,7 @@
 use Joomla\CMS\Language\LanguageFactoryInterface;
 use Joomla\CMS\Language\LanguageHelper;
 use Joomla\CMS\Language\Multilanguage;
+use Joomla\CMS\Language\Text;
 use Joomla\CMS\Plugin\CMSPlugin;
 use Joomla\CMS\Router\Route;
 use Joomla\CMS\Router\Router;
@@ -158,6 +159,11 @@ public function __construct(
                 }
             }
         }
+
+        if (!\count($this->sefs)) {
+            $this->loadLanguage();
+            $app->enqueueMessage(Text::_('PLG_SYSTEM_LANGUAGEFILTER_ERROR_NO_CONTENT_LANGUAGE'), 'error');
+        }
     }
 
     /**