diff --git a/core/modules/system/tests/modules/form_test/src/interdiff-2560467-9-10.txt b/core/modules/system/tests/modules/form_test/src/interdiff-2560467-9-10.txt
deleted file mode 100644
index 484aeaa..0000000
--- a/core/modules/system/tests/modules/form_test/src/interdiff-2560467-9-10.txt
+++ /dev/null
@@ -1,133 +0,0 @@
-diff --git a/core/includes/theme.inc.rej b/core/includes/theme.inc.rej
-deleted file mode 100644
-index a2c1811..0000000
---- a/core/includes/theme.inc.rej
-+++ /dev/null
-@@ -1,14 +0,0 @@
--diff a/core/includes/theme.inc b/core/includes/theme.inc	(rejected hunks)
--@@ -1146,6 +1146,12 @@ function template_preprocess_container(&$variables) {
-- 
--   $variables['children'] = $element['#children'];
--   $variables['attributes'] = $element['#attributes'];
--+
--+  // Display any error messages.
--+  $variables['errors'] = NULL;
--+  if (!empty($element['#errors']) && empty($element['#error_no_message'])) {
--+   $variables['errors'] = $element['#errors'];
--+  }
-- }
-- 
-- /**
-diff --git a/core/modules/system/src/Tests/Form/ElementTest.php b/core/modules/system/src/Tests/Form/ElementTest.php
-index 684e13a..0ff443f 100644
---- a/core/modules/system/src/Tests/Form/ElementTest.php
-+++ b/core/modules/system/src/Tests/Form/ElementTest.php
-@@ -162,11 +162,18 @@ public function testFormAutocomplete() {
-   }
- 
-   /**
--   * Tests form element error messages.
-+   * Tests form details element error messages.
-    */
--  public function testFormElementErrors() {
-+  public function testFormDetailsErrors() {
-     $this->drupalPostForm('form_test/details-form', [], 'Submit');
-     $this->assertText('I am an error on the details element.');
-   }
-+  /**
-+   * Tests form container element error messages.
-+   */
-+  public function testFormElementErrors() {
-+    $this->drupalPostForm('form_test/container-form', [], 'Submit');
-+    $this->assertText('I am an error on the container element.');
-+  }
- 
- }
-diff --git a/core/modules/system/templates/container.html.twig.rej b/core/modules/system/templates/container.html.twig.rej
-deleted file mode 100644
-index 9f64af5..0000000
---- a/core/modules/system/templates/container.html.twig.rej
-+++ /dev/null
-@@ -1,22 +0,0 @@
--diff a/core/modules/system/templates/container.html.twig b/core/modules/system/templates/container.html.twig	(rejected hunks)
--@@ -12,6 +12,7 @@
--  *
--  * Available variables:
--  * - attributes: HTML attributes for the containing element.
--+ * - errors: (optional) Any errors for this container element, may not be set.
--  * - children: The rendered child elements of the container.
--  * - has_parent: A flag to indicate that the container has one or more parent
--      containers.
--@@ -27,4 +28,11 @@
--     has_parent ? 'form-wrapper',
--   ]
-- %}
---<div{{ attributes.addClass(classes) }}>{{ children }}</div>
--+<div{{ attributes.addClass(classes) }}>
--+{% if errors %}
--+  <div>
--+    {{ errors }}
--+  </div>
--+{% endif %}
--+{{ children }}
--+</div>
-diff --git a/core/modules/system/tests/modules/form_test/form_test.routing.yml b/core/modules/system/tests/modules/form_test/form_test.routing.yml
-index 42a6ba4..327d7fd 100644
---- a/core/modules/system/tests/modules/form_test/form_test.routing.yml
-+++ b/core/modules/system/tests/modules/form_test/form_test.routing.yml
-@@ -409,6 +409,14 @@ form_test.details_form:
-   requirements:
-     _access: 'TRUE'
- 
-+form_test.container_form:
-+  path: '/form_test/container-form'
-+  defaults:
-+    _form: '\Drupal\form_test\Form\FormTestContainerForm'
-+    _title: 'Form contaner form test'
-+  requirements:
-+    _access: 'TRUE'
-+
- form_test.description_display:
-   path: '/form_test/form-descriptions'
-   defaults:
-diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
-index 5949679..55fcbfd 100644
---- a/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
-+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestDetailsForm.php
-@@ -6,7 +6,7 @@
- use Drupal\Core\Form\FormStateInterface;
- 
- /**
-- * Builds a simple form to test the #group property on #type 'container'.
-+ * Builds a simple form to test the #group property on #type 'details'.
-  */
- class FormTestDetailsForm extends FormBase {
- 
-diff --git a/core/themes/classy/templates/form/container.html.twig.rej b/core/themes/classy/templates/form/container.html.twig.rej
-deleted file mode 100644
-index db1ca62..0000000
---- a/core/themes/classy/templates/form/container.html.twig.rej
-+++ /dev/null
-@@ -1,22 +0,0 @@
--diff a/core/themes/classy/templates/form/container.html.twig b/core/themes/classy/templates/form/container.html.twig	(rejected hunks)
--@@ -12,6 +12,7 @@
--  *
--  * Available variables:
--  * - attributes: HTML attributes for the containing element.
--+ * - errors: (optional) Any errors for this container element, may not be set.
--  * - children: The rendered child elements of the container.
--  * - has_parent: A flag to indicate that the container has one or more parent
--      containers.
--@@ -25,4 +26,11 @@
--     has_parent ? 'form-wrapper',
--   ]
-- %}
---<div{{ attributes.addClass(classes) }}>{{ children }}</div>
--+<div{{ attributes.addClass(classes) }}>
--+{% if errors %}
--+  <div class="form-item--error-message">
--+    <strong>{{ errors }}</strong>
--+  </div>
--+{% endif %}
--+{{ children }}
--+</div>