Issue #2465425 by jibran, pjonckiere, idebr: Vocabulary listing missing add taxonomy term link

core/modules/taxonomy/src/Tests/VocabularyUiTest.php

@@ -8,6 +8,7 @@
 namespace Drupal\taxonomy\Tests;
 use Drupal\Component\Utility\Unicode;
 
+use Drupal\Core\Url;
 use Drupal\taxonomy\Entity\Vocabulary;
 
 /**
@@ -50,6 +51,7 @@ function testVocabularyInterface() {
     // Edit the vocabulary.
     $this->drupalGet('admin/structure/taxonomy');
     $this->assertText($edit['name'], 'Vocabulary found in the vocabulary overview listing.');
+    $this->assertLinkByHref(Url::fromRoute('entity.taxonomy_term.add_form', ['taxonomy_vocabulary' => $edit['vid']])->toString());
     $this->clickLink(t('Edit vocabulary'));
     $edit = array();
     $edit['name'] = $this->randomMachineName();

core/modules/taxonomy/src/VocabularyListBuilder.php

@@ -10,6 +10,7 @@
 use Drupal\Core\Config\Entity\DraggableListBuilder;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
 
 /**
  * Defines a class to build a listing of taxonomy vocabulary entities.
@@ -48,7 +49,7 @@ public function getDefaultOperations(EntityInterface $entity) {
     $operations['add'] = array(
       'title' => t('Add terms'),
       'weight' => 10,
-      'url' => $entity->urlInfo('add-form'),
+      'url' => Url::fromRoute('entity.taxonomy_term.add_form', ['taxonomy_vocabulary' => $entity->id()]),
     );
     unset($operations['delete']);