reverted:
--- b/core/tests/Drupal/FunctionalTests/Entity/EntityFormCorrectUserInputMappingOnFieldDeltaElementsTest.php
+++ /dev/null
@@ -1,112 +0,0 @@
-<?php
-
-namespace Drupal\FunctionalTests\Entity;
-
-use Drupal\Core\Entity\ContentEntityInterface;
-use Drupal\Core\Entity\ContentEntityStorageInterface;
-use Drupal\Core\Field\FieldStorageDefinitionInterface;
-use Drupal\field\Entity\FieldConfig;
-use Drupal\field\Entity\FieldStorageConfig;
-use Drupal\Tests\BrowserTestBase;
-
-/**
- * Tests the correct mapping of user input on the correct field delta elements.
- *
- * @group Entity
- */
-class EntityFormCorrectUserInputMappingOnFieldDeltaElementsTest extends BrowserTestBase  {
-
-  /**
-   * The ID of the type of the entity under test.
-   *
-   * @var string
-   */
-  protected $entityTypeId;
-
-  /**
-   * The field name with multiple properties being test with the entity type.
-   *
-   * @var string
-   */
-  protected $fieldName;
-
-  /**
-   * {@inheritdoc}
-   */
-  public static $modules = ['entity_test'];
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setUp() {
-    parent::setUp();
-    $web_user = $this->drupalCreateUser(['administer entity_test content']);
-    $this->drupalLogin($web_user);
-
-    // Create a field of field type "shape" with unlimited cardinality on the
-    // entity type "entity_test".
-    $this->entityTypeId = 'entity_test';
-    $this->fieldName = 'shape';
-
-    FieldStorageConfig::create([
-      'field_name' => $this->fieldName,
-      'entity_type' => $this->entityTypeId,
-      'type' => 'shape',
-      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
-    ])
-      ->save();
-    FieldConfig::create([
-      'entity_type' => $this->entityTypeId,
-      'field_name' => $this->fieldName,
-      'bundle' => $this->entityTypeId,
-      'label' => 'Shape',
-      'translatable' => FALSE,
-    ])
-      ->save();
-
-    entity_get_form_display($this->entityTypeId, $this->entityTypeId, 'default')
-      ->setComponent($this->fieldName, ['type' => 'shape_only_color_editable_widget'])
-      ->save();
-  }
-
-  /**
-   * Tests the correct user input mapping on complex fields.
-   */
-  public function testCorrectUserInputMappingOnComplexFields() {
-    /** @var ContentEntityStorageInterface $storage */
-    $storage = $this->container->get('entity_type.manager')->getStorage($this->entityTypeId);
-
-    /** @var ContentEntityInterface $entity */
-    $entity = $storage->create([$this->fieldName => [
-      ['shape' => 'rectangle', 'color' => 'green'],
-      ['shape' => 'circle', 'color' => 'blue'],
-    ]]);
-    $entity->save();
-
-    $this->drupalGet($this->entityTypeId . '/manage/' . $entity->id() . '/edit');
-
-    // Rearrange the field items.
-    $edit = array(
-      "$this->fieldName[0][_weight]" => 0,
-      "$this->fieldName[1][_weight]" => -1,
-    );
-    // Executing an ajax call is important before saving as it will trigger
-    // form state caching and so if for any reasons the form is rebuilt with
-    // the entity built based on the user submitted values then the correct
-    // mapping will break after the form builder maps over the new form the
-    // user submitted values based on the previous delta ordering.
-    $this->drupalPostForm(NULL, $edit, t('Add another item'));
-    $this->drupalPostForm(NULL, [], t('Save'));
-
-    // Reload the entity.
-    $entity = $storage->load($entity->id());
-
-    // Assert that after rearranging the field items the user input will be
-    // mapped on the correct delta field items.
-    $this->assertEquals($entity->get($this->fieldName)->getValue(), [
-      ['shape' => 'circle', 'color' => 'blue'],
-      ['shape' => 'rectangle', 'color' => 'green'],
-    ]);
-  }
-
-}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormCorrectUserInputMappingOnFieldDeltaElementsTest.php
@@ -0,0 +1,117 @@
+<?php
+
+namespace Drupal\FunctionalTests\Entity;
+
+use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Entity\ContentEntityStorageInterface;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the correct mapping of user input on the correct field delta elements.
+ *
+ * @group Entity
+ */
+class ContentEntityFormCorrectUserInputMappingOnFieldDeltaElementsTest extends BrowserTestBase  {
+
+  /**
+   * The ID of the type of the entity under test.
+   *
+   * @var string
+   */
+  protected $entityTypeId;
+
+  /**
+   * The field name with multiple properties being test with the entity type.
+   *
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $web_user = $this->drupalCreateUser(['administer entity_test content']);
+    $this->drupalLogin($web_user);
+
+    // Create a field of field type "shape" with unlimited cardinality on the
+    // entity type "entity_test".
+    $this->entityTypeId = 'entity_test';
+    $this->fieldName = 'shape';
+
+    FieldStorageConfig::create([
+      'field_name' => $this->fieldName,
+      'entity_type' => $this->entityTypeId,
+      'type' => 'shape',
+      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+    ])
+      ->save();
+    FieldConfig::create([
+      'entity_type' => $this->entityTypeId,
+      'field_name' => $this->fieldName,
+      'bundle' => $this->entityTypeId,
+      'label' => 'Shape',
+      'translatable' => FALSE,
+    ])
+      ->save();
+
+    entity_get_form_display($this->entityTypeId, $this->entityTypeId, 'default')
+      ->setComponent($this->fieldName, ['type' => 'shape_only_color_editable_widget'])
+      ->save();
+  }
+
+  /**
+   * Tests the correct user input mapping on complex fields.
+   */
+  public function testCorrectUserInputMappingOnComplexFields() {
+    /** @var ContentEntityStorageInterface $storage */
+    $storage = $this->container->get('entity_type.manager')->getStorage($this->entityTypeId);
+
+    /** @var ContentEntityInterface $entity */
+    $entity = $storage->create([$this->fieldName => [
+      ['shape' => 'rectangle', 'color' => 'green'],
+      ['shape' => 'circle', 'color' => 'blue'],
+    ]]);
+    $entity->save();
+
+    $this->drupalGet($this->entityTypeId . '/manage/' . $entity->id() . '/edit');
+
+    // Rearrange the field items.
+    $edit = array(
+      "$this->fieldName[0][_weight]" => 0,
+      "$this->fieldName[1][_weight]" => -1,
+    );
+    // Executing an ajax call is important before saving as it will trigger
+    // form state caching and so if for any reasons the form is rebuilt with
+    // the entity built based on the user submitted values with already
+    // reordered field items then the correct mapping will break after the form
+    // builder maps over the new form the user submitted values based on the
+    // previous delta ordering.
+    //
+    // This is how currently the form building process works and this test
+    // ensures the correct behavior no matter what changes would be made to the
+    // form builder or the content entity forms.
+    $this->drupalPostForm(NULL, $edit, t('Add another item'));
+    $this->drupalPostForm(NULL, [], t('Save'));
+
+    // Reload the entity.
+    $entity = $storage->load($entity->id());
+
+    // Assert that after rearranging the field items the user input will be
+    // mapped on the correct delta field items.
+    $this->assertEquals($entity->get($this->fieldName)->getValue(), [
+      ['shape' => 'circle', 'color' => 'blue'],
+      ['shape' => 'rectangle', 'color' => 'green'],
+    ]);
+  }
+
+}