[SwiftmailerBundle] Allow for the Swift_NullTransport to be chosen in the Configuration class

src/Symfony/Bundle/SwiftmailerBundle/DependencyInjection/Configuration.php

@@ -41,7 +41,7 @@ class Configuration
                 ->scalarNode('transport')
                     ->defaultValue('smtp')
                     ->validate()
-                        ->ifNotInArray(array ('smtp', 'mail', 'sendmail', 'gmail'))
+                        ->ifNotInArray(array ('smtp', 'mail', 'sendmail', 'gmail', null))
                         ->thenInvalid('The %s transport is not supported')
                     ->end()
                 ->end()

src/Symfony/Bundle/SwiftmailerBundle/Tests/DependencyInjection/SwiftmailerExtensionTest.php

@@ -24,17 +24,28 @@ class SwiftmailerExtensionTest extends TestCase
         $loader = new SwiftmailerExtension();
 
         $loader->load(array(array()), $container);
-        $this->assertEquals('Swift_Mailer', $container->getParameter('swiftmailer.class'), '->mailerLoad() loads the swiftmailer.xml file if not already loaded');
+        $this->assertEquals('Swift_Mailer', $container->getParameter('swiftmailer.class'), '->load() loads the swiftmailer.xml file if not already loaded');
 
         $loader->load(array(array('transport' => 'sendmail')), $container);
-        $this->assertEquals('sendmail', $container->getParameter('swiftmailer.transport.name'), '->mailerLoad() overrides existing configuration options');
+        $this->assertEquals('sendmail', $container->getParameter('swiftmailer.transport.name'), '->load() overrides existing configuration options');
         $this->assertEquals('swiftmailer.transport.sendmail', (string) $container->getAlias('swiftmailer.transport'));
 
         $loader->load(array(array()), $container);
-        $this->assertEquals('smtp', $container->getParameter('swiftmailer.transport.name'), '->mailerLoad() provides default values for configuration options');
+        $this->assertEquals('smtp', $container->getParameter('swiftmailer.transport.name'), '->load() provides default values for configuration options');
         $this->assertEquals('swiftmailer.transport.smtp', (string) $container->getAlias('swiftmailer.transport'));
     }
 
+    public function testNullTransport()
+    {
+        $container = new ContainerBuilder();
+        $container->setParameter('kernel.debug', false);
+        $loader = new SwiftmailerExtension();
+
+        $loader->load(array(array('transport' => null)), $container);
+        $this->assertEquals('null', $container->getParameter('swiftmailer.transport.name'), '->load() uses the "null" string transport when transport is null');
+        $this->assertEquals('swiftmailer.transport.null', (string) $container->getAlias('swiftmailer.transport'));
+    }
+
     public function testSpool()
     {
         $container = new ContainerBuilder();