[-] FO: Fix lang links when url rewrite is not activated

classes/Dispatcher.php

@@ -143,7 +143,9 @@ class DispatcherCore
 	 * @var bool If true, use routes to build URL (mod rewrite must be activated)
 	 */
 	protected $use_routes = false;
-
+	
+	protected $multilang_activated = false;
+	
 	/**
 	 * @var array List of loaded routes
 	 */
@@ -225,6 +227,9 @@ class DispatcherCore
 		if ($this->front_controller == self::FC_FRONT)
 			Tools::switchLanguage();
 
+		if (Language::isMultiLanguageActivated())
+			$this->multilang_activated = true;
+
 		$this->loadRoutes();
 	}
 
@@ -616,7 +621,11 @@ class DispatcherCore
 
 			if (!empty($route['controller']))
 				$query_params['controller'] = $route['controller'];
-			$url = 'index.php?'.http_build_query(array_merge($add_params, $query_params), '', '&');
+			$query = http_build_query(array_merge($add_params, $query_params), '', '&');
+			if ($this->multilang_activated)
+				$query .= (!empty($query) ? '&' : '').'id_lang='.(int)$id_lang;
+			$url = 'index.php?'.$query;
+			
 		}
 
 		return $url.$anchor;

classes/Tools.php

@@ -399,20 +399,8 @@ class ToolsCore
 				$context->language = $language;
 
 			$params = $_GET;
-			unset($params['id_lang']);
-
-			if (!Configuration::get('PS_REWRITING_SETTINGS'))
-			{
-				if (empty($params['controller']))
-					unset($params['controller']);
-				elseif (!empty(Context::getContext()->controller->php_self))
-					$params['controller'] = Context::getContext()->controller->php_self;
-					
-				if (empty($params))
-					Tools::redirect('index.php');
-				else
-					Tools::redirect('index.php?'.http_build_query($params));
-			}
+			if (Configuration::get('PS_REWRITING_SETTINGS') || !Language::isMultiLanguageActivated())
+				unset($params['id_lang']);
 		}
 	}