Issue #2718655 by dawehner, Jo Fitzgerald, Wim Leers: #type actions with...

Issue #2718655 by dawehner, Jo Fitzgerald, Wim Leers: #type actions with dropbutton loses bubbleable metadata

core/lib/Drupal/Core/Render/Element/Actions.php

@@ -3,6 +3,7 @@
 namespace Drupal\Core\Render\Element;
 
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\Core\Render\Element;
 
 /**
@@ -103,6 +104,10 @@ public static function preRenderActionsDropbutton(&$element, FormStateInterface
         $dropbuttons[$dropbutton]['#links'][$key] = [
           'title' => $button,
         ];
+        // Merge metadata like drupalSettings.
+        BubbleableMetadata::createFromRenderArray($dropbuttons[$dropbutton])
+          ->merge(BubbleableMetadata::createFromRenderArray($element[$key]))
+          ->applyTo($dropbuttons[$dropbutton]);
       }
     }
     // @todo For now, all dropbuttons appear first. Consider to invent a more

core/tests/Drupal/KernelTests/Core/Render/Element/ActionsTest.php

+<?php
+
+namespace Drupal\KernelTests\Core\Render\Element;
+
+use Drupal\Core\Form\FormInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * @coversDefaultClass \Drupal\Core\Render\Element\Actions
+ * @group Render
+ */
+class ActionsTest extends KernelTestBase implements FormInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['system'];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) {
+    $form['actions'] = ['#type' => 'actions'];
+    $form['actions']['key'] = [
+      '#type' => 'submit',
+      '#value' => 'Key',
+      '#dropbutton' => 'submit',
+      '#cache' => [
+        'tags' => ['foo'],
+      ],
+      '#attached' => [
+        'library' => [
+          'system/base',
+        ],
+      ],
+    ];
+    $form['actions']['submit'] = [
+      '#type' => 'submit',
+      '#value' => 'Save',
+    ];
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validateForm(array &$form, FormStateInterface $form_state) {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+  }
+
+  public function testDropbuttonWithBubbleableMetadata() {
+    $result = \Drupal::formBuilder()->getForm($this);
+    \Drupal::service('renderer')->renderRoot($result);
+    $this->assertEquals(['system/base', 'core/drupal.dropbutton'], $result['#attached']['library']);
+    $this->assertEquals(['foo'], $result['#cache']['tags']);
+  }
+
+}