#3035992 Stale values can be displayed by the Layout Builder UI but are saved correctly

Closes #3035992

core/modules/layout_builder/src/Hook/LayoutBuilderHooks.php

@@ -23,6 +23,7 @@
 use Drupal\layout_builder\Form\DefaultsEntityForm;
 use Drupal\layout_builder\Entity\LayoutBuilderEntityViewDisplayStorage;
 use Drupal\layout_builder\Entity\LayoutBuilderEntityViewDisplay;
+use Drupal\layout_builder\LayoutOverrideFieldHelper;
 use Drupal\Core\Url;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Hook\Attribute\Hook;
@@ -219,6 +220,26 @@ public function entityDelete(EntityInterface $entity): void {
     }
   }
 
+  /**
+   * Implements hook_entity_update().
+   */
+  #[Hook('entity_update')]
+  public function entityUpdate(EntityInterface $entity): void {
+    // See if the entity's layout must be updated with the new entity values if:
+    // 1. It is a fieldable layout
+    // 2. A layout override field is present.
+    // @todo Remove instanceof FieldableEntityInterface check in
+    //   https://www.drupal.org/node/3046216
+    if ($entity instanceof FieldableEntityInterface && $entity->hasField(OverridesSectionStorage::FIELD_NAME)) {
+      // If an entity's field values change, and it also has a layout override
+      // in the tempstore, the tempstore must be updated to reflect those new
+      // values.
+      /** @var \Drupal\layout_builder\LayoutOverrideFieldHelper $override_field_helper */
+      $override_field_helper = \Drupal::classResolver(LayoutOverrideFieldHelper::class);
+      $override_field_helper->updateTempstoreEntityContext($entity);
+    }
+  }
+
   /**
    * Implements hook_cron().
    */