[DI] Service locators can't be decorated

src/Symfony/Component/DependencyInjection/Compiler/PassConfig.php

@@ -52,14 +52,14 @@ class PassConfig
             new ValidateEnvPlaceholdersPass(),
             new ResolveChildDefinitionsPass(),
             new RegisterServiceSubscribersPass(),
-            new DecoratorServicePass(),
             new ResolveParameterPlaceHoldersPass(false),
-            new ResolveFactoryClassPass(),
             new ResolveNamedArgumentsPass(),
-            new AutowireRequiredMethodsPass(),
             new ResolveBindingsPass(),
             new ServiceLocatorTagPass(),
             new CheckDefinitionValidityPass(),
+            new DecoratorServicePass(),
+            new ResolveFactoryClassPass(),
+            new AutowireRequiredMethodsPass(),
             new AutowirePass(false),
             new ResolveTaggedIteratorArgumentPass(),
             new ResolveServiceSubscribersPass(),

src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php

@@ -24,6 +24,7 @@ use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\BarTagClass;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\FooBarTaggedClass;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\FooTagClass;
+use Symfony\Contracts\Service\ServiceProviderInterface;
 
 /**
  * This class tests the integration of the different compiler passes.
@@ -142,6 +143,29 @@ class IntegrationTest extends TestCase
         $this->assertInstanceOf(DecoratedServiceSubscriber::class, $container->get(ServiceSubscriberStub::class));
     }
 
+    public function testCanDecorateServiceLocator()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('foo', 'stdClass')->setPublic(true);
+
+        $container->register(ServiceLocator::class)
+            ->addTag('container.service_locator')
+            ->setArguments([[new Reference('foo')]])
+        ;
+
+        $container->register(DecoratedServiceLocator::class)
+            ->setDecoratedService(ServiceLocator::class)
+            ->setPublic(true)
+            ->setArguments([new Reference(DecoratedServiceLocator::class.'.inner')])
+        ;
+
+        $container->compile();
+
+        $this->assertInstanceOf(DecoratedServiceLocator::class, $container->get(DecoratedServiceLocator::class));
+        $this->assertSame($container->get('foo'), $container->get(DecoratedServiceLocator::class)->get('foo'));
+    }
+
     /**
      * @dataProvider getYamlCompileTests
      */
@@ -416,6 +440,34 @@ class DecoratedServiceSubscriber
 {
 }
 
+class DecoratedServiceLocator implements ServiceProviderInterface
+{
+    /**
+     * @var ServiceLocator
+     */
+    private $locator;
+
+    public function __construct(ServiceLocator $locator)
+    {
+        $this->locator = $locator;
+    }
+
+    public function get($id)
+    {
+        return $this->locator->get($id);
+    }
+
+    public function has($id): bool
+    {
+        return $this->locator->has($id);
+    }
+
+    public function getProvidedServices(): array
+    {
+        return $this->locator->getProvidedServices();
+    }
+}
+
 class IntegrationTestStub extends IntegrationTestStubParent
 {
 }