Issue #1836204 by sun, dawehner: Fixed Random test failure in...

Issue #1836204 by sun, dawehner: Fixed Random test failure in Drupal\system\Tests\Menu\BreadcrumbTest.

core/modules/system/lib/Drupal/system/Tests/Menu/BreadcrumbTest.php

@@ -111,10 +111,15 @@ function testBreadCrumbs() {
       'admin/structure/menu' => t('Menus'),
     );
     $this->assertBreadcrumb('admin/structure/menu/manage/tools', $trail);
+
+    $mlid_node_add = db_query('SELECT mlid FROM {menu_links} WHERE link_path = :href AND module = :module', array(
+      ':href' => 'node/add',
+      ':module' => 'system',
+    ))->fetchField();
     $trail += array(
       'admin/structure/menu/manage/tools' => t('Tools'),
     );
-    $this->assertBreadcrumb("admin/structure/menu/item/6/edit", $trail);
+    $this->assertBreadcrumb("admin/structure/menu/item/$mlid_node_add/edit", $trail);
     $this->assertBreadcrumb('admin/structure/menu/manage/tools/edit', $trail);
     $this->assertBreadcrumb('admin/structure/menu/manage/tools/add', $trail);