MAGETWO-63716: Add target to admin menu element

Author: olysenko

app/code/Magento/Backend/Block/AnchorRenderer.php

@@ -38,12 +38,12 @@ public function __construct(
     /**
      * Render menu item anchor
      *
-     * @param Item $activeItem
+     * @param Item|null $activeItem
      * @param Item $menuItem
      * @param int $level
      * @return string
      */
-    public function renderAnchor(Item $activeItem, Item $menuItem, $level)
+    public function renderAnchor($activeItem, Item $menuItem, $level)
     {
         if ($level == 1 && $menuItem->getUrl() == '#') {
             $output = '<strong class="submenu-group-title" role="presentation">'

app/code/Magento/Backend/Block/MenuItemChecker.php

@@ -15,19 +15,20 @@ class MenuItemChecker
     /**
      * Check whether given item is currently selected
      *
-     * @param Item $activeItem,
+     * @param Item|null $activeItem,
      * @param Item $item
      * @param int $level
      * @return bool
      */
     public function isItemActive(
-        Item $activeItem,
+        $activeItem,
         Item $item,
         $level
     ) {
         $output = false;
 
         if ($level == 0
+            && $activeItem instanceof \Magento\Backend\Model\Menu\Item
             && $this->isActiveItemEqualOrChild($activeItem, $item)
         ) {
             $output = true;