Issue #3067304 by larowlan, megadesk3000, nanak: Try to access $parentField ....

Issue #3067304 by larowlan, megadesk3000, nanak: Try to access $parentField . '_weight' instead of $parentField . '__weight' in loadSiblingEntityWeights()

src/Plugin/Field/FieldType/EntityReferenceHierarchy.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\entity_hierarchy\Plugin\Field\FieldType;
 
+use Drupal\Core\Field\BaseFieldDefinition;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\Core\TypedData\DataDefinition;
 use Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem;
@@ -247,7 +248,8 @@ class EntityReferenceHierarchy extends EntityReferenceItem {
       ->groupBy($parentField . '.weight')
       ->condition($key, $ids, 'IN')
       ->execute();
-    $entities = array_combine(array_column($entities, $key), array_column($entities, $parentField . '_weight'));
+    $weightSeparator = $fieldDefinition instanceof BaseFieldDefinition ? '__' : '_';
+    $entities = array_combine(array_column($entities, $key), array_column($entities, $parentField . $weightSeparator. 'weight'));
     foreach ($siblings as $node) {
       if (!isset($entities[$node->getRevisionId()])) {
         continue;

tests/modules/entity_hierarchy_test_base_field/entity_hierarchy_test_base_field.module

@@ -5,12 +5,13 @@
  * Contains main module functions.
  */
 
+use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Field\BaseFieldDefinition;
 
 /**
  * Implements hook_entity_base_field_info().
  */
-function entity_hierarchy_test_base_field_entity_base_field_info(\Drupal\Core\Entity\EntityTypeInterface $entity_type) {
+function entity_hierarchy_test_base_field_entity_base_field_info(EntityTypeInterface $entity_type) {
   if ($entity_type->id() === 'entity_test') {
     return [
       'parents' => BaseFieldDefinition::create('entity_reference_hierarchy')