Issue #2401195 by idebr, corbacho: Vocabulary restriction not working in Entity reference fields

core/modules/taxonomy/src/Plugin/entity_reference/selection/TermSelection.php

@@ -60,7 +60,8 @@ public function getReferenceableEntities($match = NULL, $match_operator = 'CONTA
     $options = array();
 
     $bundles = entity_get_bundles('taxonomy_term');
-    $bundle_names = !empty($this->instance['settings']['handler_settings']['target_bundles']) ? $this->instance['settings']['handler_settings']['target_bundles'] : array_keys($bundles);
+    $handler_settings = $this->fieldDefinition->getSetting('handler_settings');
+    $bundle_names = !empty($handler_settings['target_bundles']) ? $handler_settings['target_bundles'] : array_keys($bundles);
 
     foreach ($bundle_names as $bundle) {
       if ($vocabulary = entity_load('taxonomy_vocabulary', $bundle)) {

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

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\taxonomy\Tests\TermEntityReferenceTest.
+ */
+
+namespace Drupal\taxonomy\Tests;
+
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\field\Entity\FieldConfig;
+
+/**
+ * Tests the settings of restricting term selection to a single vocabulary.
+ *
+ * @group taxonomy
+ */
+class TermEntityReferenceTest extends TaxonomyTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('entity_reference', 'entity_reference_test', 'entity_test');
+
+  /**
+   * Tests an entity reference field restricted to a single vocabulary.
+   *
+   * Creates two vocabularies with a term, then set up the entity reference
+   * field to limit the target vocabulary to one of them, ensuring that
+   * the restriction applies.
+   */
+  function testSelectionTestVocabularyRestriction() {
+
+    // Create two vocabularies.
+    $vocabulary = $this->createVocabulary();
+    $vocabulary2 = $this->createVocabulary();
+
+    $term = $this->createTerm($vocabulary);
+    $term2 = $this->createTerm($vocabulary2);
+
+    // Create an entity reference field.
+    $field_name = 'taxonomy_' . $vocabulary->id();
+    $field_storage = FieldStorageConfig::create(array(
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'translatable' => FALSE,
+      'settings' => array(
+        'target_type' => 'taxonomy_term',
+      ),
+      'type' => 'entity_reference',
+      'cardinality' => 1,
+    ));
+    $field_storage->save();
+    $field = FieldConfig::create(array(
+      'field_storage' => $field_storage,
+      'entity_type' => 'entity_test',
+      'bundle' => 'test_bundle',
+      'settings' => array(
+        'handler' => 'default',
+        'handler_settings' => array(
+          // Restrict selection of terms to a single vocabulary.
+          'target_bundles' => array(
+            $vocabulary->id() => $vocabulary->id(),
+          ),
+        ),
+      ),
+    ));
+    $field->save();
+
+    $handler = $this->container->get('plugin.manager.entity_reference.selection')->getSelectionHandler($field);
+    $result = $handler->getReferenceableEntities();
+
+    $expected_result = array(
+      $vocabulary->id() => array(
+        $term->id() => $term->getName(),
+      ),
+    );
+
+    $this->assertIdentical($result, $expected_result, 'Terms selection restricted to a single vocabulary.');
+  }
+}