TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in count()

Problem/Motivation

After updating from version 2.0.0-alpha4 to the stable 2.0.0 release the site crashed with following error:

Drupal version 10.2.8, PHP version 8.1

TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in count() (line 185 of modules/contrib/domain_menu_access/modules/domain_menu_access_menu_block/src/Plugin/Block/DomainMenuAccessMenuMenuBlock.php).
Drupal\domain_menu_access_menu_block\Plugin\Block\DomainMenuAccessMenuMenuBlock->build() (Line: 434)
Drupal\menu_block\Plugin\Block\MenuBlock->blockAccess(Object) (Line: 127)
Drupal\Core\Block\BlockBase->access(Object, 1) (Line: 124)
Drupal\block\BlockAccessControlHandler->checkAccess(Object, 'view', Object) (Line: 109)
Drupal\Core\Entity\EntityAccessControlHandler->access(Object, 'view', Object, 1) (Line: 329)
Drupal\Core\Entity\EntityBase->access('view', NULL, 1) (Line: 63)
Drupal\block\BlockRepository->getVisibleBlocksPerRegion(Array) (Line: 137)
Drupal\block\Plugin\DisplayVariant\BlockPageVariant->build() (Line: 270)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 128)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object)
call_user_func(Array, Object, 'kernel.view', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.view') (Line: 186)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 144)
Drupal\cloudflare\CloudFlareMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 704)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

The code checks if there are menu items to render, and returns an error because the array #items does not exist.

Steps to reproduce

Update from version 2.0.0-alpha4 to version 2.0.0 and have a menu with no #items key in the render array of a menu.

Proposed resolution

Check if the key #items is present, before checking if the items array contains more than zero items.

Remaining tasks

Review the code and merge MR.

User interface changes

None

API changes

None

Data model changes

None