Issue #3035155 by AdamPS, ToneLoc, mglaman, demonde, bojanz, stephenplatz: Allow "Single variations" widget to be used inside Complex Inline Entity Forms

Author: AdamPS

modules/product/src/Plugin/Field/FieldWidget/SingleVariationWidget.php

@@ -152,7 +152,10 @@ public function extractFormValues(FieldItemListInterface $items, array $form, Fo
       return;
     }
 
-    $parents = array_merge($form['#parents'], [$this->fieldDefinition->getName(), 'widget']);
+    $parents = [$this->fieldDefinition->getName(), 'widget'];
+    if ($form['#type'] != 'inline_entity_form') {
+      $parents = array_merge($form['#parents'], $parents);
+    }
     $element = NestedArray::getValue($form, $parents);
     /** @var \Drupal\commerce\Plugin\Commerce\InlineForm\EntityInlineFormInterface $inline_form */
     $inline_form = $element['entity']['#inline_form'];