Merge branch '2.7' into 2.8

* 2.7:
  [DI] Fix dumping abstract with YamlDumper

Author: nicolas-grekas

src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php

@@ -120,6 +120,10 @@ private function addService($id, $definition)
             $code .= sprintf("        factory_class: %s\n", $this->dumper->dump($definition->getFactoryClass(false)));
         }
 
+        if ($definition->isAbstract()) {
+            $code .= "        abstract: true\n";
+        }
+
         if ($definition->isLazy()) {
             $code .= "        lazy: true\n";
         }

src/Symfony/Component/DependencyInjection/Tests/Dumper/YamlDumperTest.php

@@ -12,8 +12,10 @@
 namespace Symfony\Component\DependencyInjection\Tests\Dumper;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Dumper\YamlDumper;
+use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\Yaml\Yaml;
 
 class YamlDumperTest extends TestCase
@@ -84,6 +86,16 @@ public function testDumpAutowireData()
         $this->assertStringEqualsFile(self::$fixturesPath.'/yaml/services24.yml', $dumper->dump());
     }
 
+    public function testDumpLoad()
+    {
+        $container = new ContainerBuilder();
+        $loader = new YamlFileLoader($container, new FileLocator(self::$fixturesPath.'/yaml'));
+        $loader->load('services_dump_load.yml');
+
+        $dumper = new YamlDumper($container);
+        $this->assertStringEqualsFile(self::$fixturesPath.'/yaml/services_dump_load.yml', $dumper->dump());
+    }
+
     private function assertEqualYamlStructure($yaml, $expected, $message = '')
     {
         $this->assertEquals(Yaml::parse($expected), Yaml::parse($yaml), $message);

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_dump_load.yml

@@ -0,0 +1,4 @@
+
+services:
+    foo:
+        abstract: true