diff -u b/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
--- b/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2451,14 +2451,11 @@
   // We do not use drupal_static() here because we do not have a mechanism by
   // which to reinitialize the stored objects, so a drupal_static_reset() call
   // would leave Drupal in a nonfunctional state.
-  static $container = NULL;
+  static $container = FALSE;
   if (isset($new_container)) {
     $container = $new_container;
   }
-  if ($container) {
-    return $container;
-  }
-  return FALSE;
+  return $container;
 }
 
 /**
only in patch2:
unchanged:
--- a/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
@@ -30,11 +30,6 @@ public static function getInfo() {
    * Tests DIC compilation.
    */
   function testCompileDIC() {
-    // Because we'll be instantiating a new kernel during this test, the
-    // container stored in drupal_container() will be updated as a side effect.
-    // We need to be able to restore it to the correct one at the end of this
-    // test.
-    $original_container = drupal_container();
     $classloader = drupal_classloader();
     global $conf;
     $conf['php_storage']['service_container']= array(
@@ -63,9 +58,6 @@ function testCompileDIC() {
       !$refClass->isSubclassOf('Symfony\Component\DependencyInjection\ContainerBuilder');
     $this->assertTrue($is_compiled_container);
 
-    // Reset the container.
-    drupal_container(NULL, TRUE);
-
     // Now use the read-only storage implementation, simulating a "production"
     // environment.
     $conf['php_storage']['service_container']['class'] = 'Drupal\Component\PhpStorage\FileReadOnlyStorage';
@@ -89,9 +81,6 @@ function testCompileDIC() {
     // modules.
     $this->assertFalse($container->has('bundle_test_class'));
 
-    // Reset the container.
-    drupal_container(NULL, TRUE);
-
     // Add another module so that we can test that the new module's bundle is
     // registered to the new container.
     $module_enabled['bundle_test'] = 'bundle_test';
@@ -113,8 +102,5 @@ function testCompileDIC() {
     $classloader = $container->get('class_loader');
     $refClass = new ReflectionClass($classloader);
     $this->assertTrue($refClass->hasMethod('getNamespaces'), 'Container has a classloader');
-
-    // Restore the original container.
-    drupal_container($original_container);
   }
 }