Issue #2105123 by pwolanin: Add a currentUser() method to \Drupal\Core\Plugin\PluginBase.

core/lib/Drupal/Core/Plugin/PluginBase.php

@@ -22,6 +22,25 @@ abstract class PluginBase extends ComponentPluginBase {
    */
   protected $translationManager;
 
+  /**
+   * Current user object.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $currentUser;
+
+  /**
+   * Gets the current active user.
+   *
+   * @return \Drupal\Core\Session\AccountInterface
+   */
+  protected function currentUser() {
+    if (!$this->currentUser) {
+      $this->currentUser = \Drupal::currentUser();
+    }
+    return $this->currentUser;
+  }
+
   /**
    * Translates a string to the current language or to a given language.
    *

core/modules/user/lib/Drupal/user/Plugin/Search/UserSearch.php

@@ -120,7 +120,7 @@ class UserSearch extends SearchPluginBase implements AccessibleInterface {
       ->select('users')
       ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
     $query->fields('users', array('uid'));
-    $user_account = $this->request->attributes->get('_account');
+    $user_account = $this->currentUser();
     if ($user_account->hasPermission('administer users')) {
       // Administrators can also search in the otherwise private email field, and
       // they don't need to be restricted to only active users.