[FrameworkBundle] fix serializer config check

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -971,7 +971,7 @@ class FrameworkExtension extends Extension
             );
         }
 
-        if ($config['name_converter']) {
+        if (isset($config['name_converter']) && $config['name_converter']) {
             $container->getDefinition('serializer.normalizer.object')->replaceArgument(1, new Reference($config['name_converter']));
         }
     }

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/php/serializer_disabled.php

@@ -0,0 +1,7 @@
+<?php
+
+$container->loadFromExtension('framework', array(
+    'serializer' => array(
+        'enabled' => false,
+    ),
+));

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/php/serializer_enabled.php

@@ -0,0 +1,7 @@
+<?php
+
+$container->loadFromExtension('framework', array(
+    'serializer' => array(
+        'enabled' => true,
+    ),
+));

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/xml/serializer_disabled.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:framework="http://symfony.com/schema/dic/symfony"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd
+        http://symfony.com/schema/dic/symfony http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
+
+    <framework:config>
+        <framework:serializer enabled="false" />
+    </framework:config>
+</container>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/xml/serializer_enabled.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:framework="http://symfony.com/schema/dic/symfony"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd
+        http://symfony.com/schema/dic/symfony http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
+
+    <framework:config>
+        <framework:serializer enabled="true" />
+    </framework:config>
+</container>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/yml/serializer_disabled.yml

@@ -0,0 +1,3 @@
+framework:
+    serializer:
+        enabled: false

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/yml/serializer_enabled.yml

@@ -0,0 +1,3 @@
+framework:
+    serializer:
+        enabled: true

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php

@@ -472,6 +472,20 @@ abstract class FrameworkExtensionTest extends TestCase
         $this->assertSame('assets.packages', (string) $packages);
     }
 
+    public function testSerializerServiceIsRegisteredWhenEnabled()
+    {
+        $container = $this->createContainerFromFile('serializer_enabled');
+
+        $this->assertTrue($container->hasDefinition('serializer'));
+    }
+
+    public function testSerializerServiceIsNotRegisteredWhenDisabled()
+    {
+        $container = $this->createContainerFromFile('serializer_disabled');
+
+        $this->assertFalse($container->hasDefinition('serializer'));
+    }
+
     protected function createContainer(array $data = array())
     {
         return new ContainerBuilder(new ParameterBag(array_merge(array(