Issue #2995893 by tim.plunkett, Dylan Donkersgoed: Layout builder chokes on form exceptions that are part of natural form processing

core/modules/layout_builder/src/Plugin/Block/FieldBlock.php

@@ -14,6 +14,7 @@ use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FormatterInterface;
 use Drupal\Core\Field\FormatterPluginManager;
+use Drupal\Core\Form\EnforcedResponseException;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\Plugin\ContextAwarePluginInterface;
@@ -155,6 +156,10 @@ class FieldBlock extends BlockBase implements ContextAwarePluginInterface, Conta
     try {
       $build = $entity->get($this->fieldName)->view($display_settings);
     }
+    // @todo Remove in https://www.drupal.org/project/drupal/issues/2367555.
+    catch (EnforcedResponseException $e) {
+      throw $e;
+    }
     catch (\Exception $e) {
       $build = [];
       $this->logger->warning('The field "%field" failed to render with the error of "%error".', ['%field' => $this->fieldName, '%error' => $e->getMessage()]);

core/modules/layout_builder/tests/src/Kernel/FieldBlockTest.php

@@ -10,6 +10,7 @@ use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\FormatterPluginManager;
+use Drupal\Core\Form\EnforcedResponseException;
 use Drupal\Core\Plugin\Context\EntityContextDefinition;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
@@ -20,6 +21,7 @@ use Prophecy\Promise\ReturnPromise;
 use Prophecy\Promise\ThrowPromise;
 use Prophecy\Prophecy\ProphecyInterface;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpFoundation\Response;
 
 /**
  * @coversDefaultClass \Drupal\layout_builder\Plugin\Block\FieldBlock
@@ -285,4 +287,21 @@ class FieldBlockTest extends EntityKernelTestBase {
     return $data;
   }
 
+  /**
+   * Tests a field block that throws a form exception.
+   *
+   * @todo Remove in https://www.drupal.org/project/drupal/issues/2367555.
+   */
+  public function testBuildWithFormException() {
+    $field = $this->prophesize(FieldItemListInterface::class);
+    $field->view(Argument::type('array'))->willThrow(new EnforcedResponseException(new Response()));
+
+    $entity = $this->prophesize(FieldableEntityInterface::class);
+    $entity->get('the_field_name')->willReturn($field->reveal());
+
+    $block = $this->getTestBlock($entity);
+    $this->setExpectedException(EnforcedResponseException::class);
+    $block->build();
+  }
+
 }