diff --git a/core/includes/entity.inc b/core/includes/entity.inc
index b6b92b0..a29a7e8 100644
--- a/core/includes/entity.inc
+++ b/core/includes/entity.inc
@@ -522,52 +522,6 @@ function entity_get_form(EntityInterface $entity, $operation = 'default', array
 }
 
 /**
- * Copies submitted values to entity properties for simple entity forms.
- *
- * During the submission handling of an entity form's "Save", "Preview", and
- * possibly other buttons, the form state's entity needs to be updated with the
- * submitted form values. Each entity form implements its own builder function
- * for doing this, appropriate for the particular entity and form, whereas
- * modules may specify additional builder functions in $form['#entity_builders']
- * for copying the form values of added form elements to entity properties.
- * Many of the main entity builder functions can call this helper function to
- * re-use its logic of copying $form_state['values'][PROPERTY] values to
- * $entity->PROPERTY for all entries in $form_state['values'] that are not
- * field data, and calling field_attach_extract_form_values() to copy field
- * data. Apart from that this helper invokes any additional builder functions
- * that have been specified in $form['#entity_builders'].
- *
- * For some entity forms (e.g., forms with complex non-field data and forms that
- * simultaneously edit multiple entities), this behavior may be inappropriate,
- * so the builder function for such forms needs to implement the required
- * functionality instead of calling this function.
- */
-function entity_form_submit_build_entity($entity_type, $entity, $form, &$form_state, array $options = array()) {
-  $info = entity_get_info($entity_type);
-
-  // Copy top-level form values that are not for fields to entity properties,
-  // without changing existing entity properties that are not being edited by
-  // this form. Copying field values must be done using
-  // field_attach_extract_form_values().
-  $values_excluding_fields = $info['fieldable'] ? array_diff_key($form_state['values'], field_info_instances($entity_type, $entity->bundle())) : $form_state['values'];
-  foreach ($values_excluding_fields as $key => $value) {
-    $entity->set($key, $value);
-  }
-
-  // Invoke all specified builders for copying form values to entity properties.
-  if (isset($form['#entity_builders'])) {
-    foreach ($form['#entity_builders'] as $function) {
-      call_user_func_array($function, array($entity_type, $entity, &$form, &$form_state));
-    }
-  }
-
-  // Copy field values to the entity.
-  if ($info['fieldable']) {
-    field_attach_extract_form_values($entity, $form, $form_state, $options);
-  }
-}
-
-/**
  * Returns an entity list controller for a given entity type.
  *
  * @param string $entity_type
diff --git a/core/lib/Drupal/Core/Entity/EntityFormController.php b/core/lib/Drupal/Core/Entity/EntityFormController.php
index 570dfe5..f384e16 100644
--- a/core/lib/Drupal/Core/Entity/EntityFormController.php
+++ b/core/lib/Drupal/Core/Entity/EntityFormController.php
@@ -355,9 +355,24 @@ public function buildEntity(array $form, array &$form_state) {
     // the controller to be the one before caching. Ensure to have the
     // controller of the current request.
     $form_state['controller'] = $this;
-    // @todo Move entity_form_submit_build_entity() here.
-    // @todo Exploit the Field API to process the submitted entity field.
-    entity_form_submit_build_entity($entity->entityType(), $entity, $form, $form_state, array('langcode' => $this->getFormLangcode($form_state)));
+
+    // Copy top-level form values to entity properties, without changing
+    // existing entity properties that are not being edited by
+    // this form.
+    // @todo: This relies on a method that only exists for config and content
+    //   entities, in a different way. Consider moving this logic to a config
+    //   entity specific implementation.
+    foreach ($form_state['values'] as $key => $value) {
+      $entity->set($key, $value);
+    }
+
+    // Invoke all specified builders for copying form values to entity properties.
+    if (isset($form['#entity_builders'])) {
+      foreach ($form['#entity_builders'] as $function) {
+        call_user_func_array($function, array($entity->entityType(), $entity, &$form, &$form_state));
+      }
+    }
+
     return $entity;
   }
 
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php
index 8aea21d..dbd8065 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php
@@ -252,6 +252,34 @@ public function validate(array $form, array &$form_state) {
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function buildEntity(array $form, array &$form_state) {
+    // @todo: Remove this when menu links are content entities.
+    $entity = clone $this->entity;
+    // If you submit a form, the form state comes from caching, which forces
+    // the controller to be the one before caching. Ensure to have the
+    // controller of the current request.
+    $form_state['controller'] = $this;
+
+    // Copy top-level form values to entity properties, without changing
+    // existing entity properties that are not being edited by
+    // this form.
+    foreach ($form_state['values'] as $key => $value) {
+      $entity->$key = $value;
+    }
+
+    // Invoke all specified builders for copying form values to entity properties.
+    if (isset($form['#entity_builders'])) {
+      foreach ($form['#entity_builders'] as $function) {
+        call_user_func_array($function, array($entity->entityType(), $entity, &$form, &$form_state));
+      }
+    }
+
+    return $entity;
+  }
+
+  /**
    * Overrides EntityFormController::submit().
    */
   public function submit(array $form, array &$form_state) {