diff -u b/core/lib/Drupal/Core/Form/FormBuilder.php b/core/lib/Drupal/Core/Form/FormBuilder.php
--- b/core/lib/Drupal/Core/Form/FormBuilder.php
+++ b/core/lib/Drupal/Core/Form/FormBuilder.php
@@ -1083,8 +1083,8 @@
       $buttons = $form_state->getButtons();
       if (!$form_state->isProgrammed() && !$form_state->getTriggeringElement() && !empty($buttons)) {
         $triggering_element = $buttons[0];
-        // If there was no specific triggering button detected by an element value,
-        // try to find a triggering element by name in the user input.
+        // If there was no specific triggering button detected by an element
+        // value, try to find a triggering element by name in the user input.
         $input = $form_state->getUserInput();
         foreach ($buttons as $button_element) {
           if (isset($button_element['#name'])) {