commit eda7f70f9651fb0bc381160aa490067d67046aa1
Author: Kozma Adrian <ocsilalala@gmail.com>
Date:   Sat Jan 25 17:18:32 2014 +0200

    Reroll for #1379070.

diff --git a/core/includes/form.inc b/core/includes/form.inc
index e4f7982..82e568b 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -858,6 +858,7 @@ function form_select_options($element, $choices = NULL) {
   // isset() fails in this situation.
   $value_valid = isset($element['#value']) || array_key_exists('#value', $element);
   $value_is_array = $value_valid && is_array($element['#value']);
+  $empty_value = (empty($element['#value']) && isset($element['#properties']['empty_option']));
   $options = '';
   foreach ($choices as $key => $choice) {
     if (is_array($choice)) {
@@ -870,7 +871,8 @@ function form_select_options($element, $choices = NULL) {
     }
     else {
       $key = (string) $key;
-      if ($value_valid && (!$value_is_array && (string) $element['#value'] === $key || ($value_is_array && in_array($key, $element['#value'])))) {
+      $empty_choice = $empty_value && $key == '_none';
+      if ($value_valid && ((!$value_is_array && (string) $element['#value'] === $key || ($value_is_array && in_array($key, $element['#value']))) || $empty_choice)) {
         $selected = ' selected="selected"';
       }
       else {
diff --git a/core/modules/options/lib/Drupal/options/Tests/OptionsWidgetsTest.php b/core/modules/options/lib/Drupal/options/Tests/OptionsWidgetsTest.php
index 02304b6..c0038c2 100644
--- a/core/modules/options/lib/Drupal/options/Tests/OptionsWidgetsTest.php
+++ b/core/modules/options/lib/Drupal/options/Tests/OptionsWidgetsTest.php
@@ -378,6 +378,7 @@ function testSelectListMultiple() {
 
     // Display form: with no field data, nothing is selected.
     $this->drupalGet('entity_test/manage/' . $entity->id());
+    $this->assertOptionSelected("edit-card-2", '_none');
     $this->assertNoOptionSelected('edit-card-2', 0);
     $this->assertNoOptionSelected('edit-card-2', 1);
     $this->assertNoOptionSelected('edit-card-2', 2);