diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/argument/CategoryCid.php b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/argument/CategoryCid.php
index ec878e7..7387dd2 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/argument/CategoryCid.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/argument/CategoryCid.php
@@ -26,13 +26,11 @@ class CategoryCid extends Numeric {
    * Overrides \Drupal\views\Plugin\views\argument\Numeric::title_query().
    */
   function title_query() {
-    $titles = array();
+    $titles = db_query("SELECT title FROM {aggregator_category} where cid IN (:cid)", array(':cid' => $this->value))->fetchCol();
 
-    $result = db_query("SELECT title FROM {aggregator_category} where cid IN (:cid)", array(':cid' => $this->value))->fetchCol();
-    foreach ($result as $category) {
-      $titles[] = check_plain($category->title);
-    }
-    return $titles;
+    return array_map(function ($title) {
+      return check_plain($title);
+    }, $titles);
   }
 
 }
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/row/Rss.php b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/row/Rss.php
index da5b16d..13a90b5 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/row/Rss.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/views/row/Rss.php
@@ -95,9 +95,11 @@ function render($row) {
       ),
     );
 
-    foreach ($entity->elements as $element) {
-      if (isset($element['namespace'])) {
-        $this->view->style_plugin->namespaces = array_merge($this->view->style_plugin->namespaces, $element['namespace']);
+    if (isset($entity->elements)) {
+      foreach ($entity->elements as $element) {
+        if (isset($element['namespace'])) {
+          $this->view->style_plugin->namespaces = array_merge($this->view->style_plugin->namespaces, $element['namespace']);
+        }
       }
     }