Issue #1827424 by EclipseGc, tim.plunkett, Fabianx, dawehner: Fixed Parse annotations recursively.

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

@@ -36,14 +36,32 @@ class Plugin implements AnnotationInterface {
    * classed annotations that were used.
    */
   public function __construct($values) {
+    $this->definition = $this->parse($values);
+  }
+
+  /**
+   * Parses an annotation into its definition.
+   *
+   * @param array $values
+   *   The annotation array.
+   *
+   * @return array
+   *  The parsed annotation as a definition.
+   */
+  protected function parse(array $values) {
+    $definitions = array();
     foreach ($values as $key => $value) {
       if ($value instanceof AnnotationInterface) {
-        $this->definition[$key] = $value->get();
+        $definitions[$key] = $value->get();
+      }
+      elseif (is_array($value)) {
+        $definitions[$key] = $this->parse($value);
       }
       else {
-        $this->definition[$key] = $value;
+        $definitions[$key] = $value;
       }
     }
+    return $definitions;
   }
 
   /**

core/modules/system/lib/Drupal/system/Tests/Plugin/Discovery/AnnotatedClassDiscoveryTest.php

@@ -31,6 +31,15 @@ public function setUp() {
         'color' => 'green',
         'class' => 'Drupal\plugin_test\Plugin\plugin_test\fruit\Apple',
       ),
+      'banana' => array(
+        'id' => 'banana',
+        'label' => 'Banana',
+        'color' => 'yellow',
+        'uses' => array(
+          'bread' => t('Banana bread'),
+        ),
+        'class' => 'Drupal\plugin_test\Plugin\plugin_test\fruit\Banana',
+      ),
       'cherry' => array(
         'id' => 'cherry',
         'label' => 'Cherry',

core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/fruit/Banana.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\plugin_test\Plugin\plugin_test\fruit\Banana.
+ */
+
+namespace Drupal\plugin_test\Plugin\plugin_test\fruit;
+
+use Drupal\Core\Annotation\Plugin;
+use Drupal\Core\Annotation\Translation;
+
+/**
+ * @Plugin(
+ *   id = "banana",
+ *   label = "Banana",
+ *   color = "yellow",
+ *   uses = {
+ *     "bread" = @Translation("Banana bread")
+ *   }
+ * )
+ */
+class Banana {
+
+}