Issue #3344082: Improve required validation of multiple value fields

Closes #3344082

core/lib/Drupal/Core/Field/WidgetBase.php

@@ -453,10 +453,12 @@ public static function deleteAjax(array &$form, FormStateInterface $form_state)
    * Generates the form element for a single copy of the widget.
    */
   protected function formSingleElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
+    $is_multiple = $this->fieldDefinition->getFieldStorageDefinition()->isMultiple();
+    $is_field_required = $this->fieldDefinition->isRequired();
     $element += [
       '#field_parents' => $form['#parents'],
-      // Only the first widget should be required.
-      '#required' => $delta == 0 && $this->fieldDefinition->isRequired(),
+      // Only the first widget of a single element should be required.
+      '#required' => $delta == 0 && $is_field_required && !$is_multiple,
       '#delta' => $delta,
       '#weight' => $delta,
     ];