bug #18394 [FrameworkBundle][2.7] Return the invokable service if its name is the class name (dunglas)

This PR was merged into the 2.7 branch.

Discussion
----------

[FrameworkBundle][2.7] Return the invokable service if its name is the class name

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/A
| License       | MIT
| Doc PR        | n/a

Backport #18289 to 2.7 as this is a bug fix.

Commits
-------

5c87d76 [FrameworkBundle] Return the invokable service if its name is the class name

src/Symfony/Bundle/FrameworkBundle/Controller/ControllerResolver.php

@@ -78,6 +78,10 @@ class ControllerResolver extends BaseControllerResolver
      */
     protected function instantiateController($class)
     {
+        if ($this->container->has($class)) {
+            return $this->container->get($class);
+        }
+
         $controller = parent::instantiateController($class);
 
         if ($controller instanceof ContainerAwareInterface) {

src/Symfony/Bundle/FrameworkBundle/Tests/Controller/ControllerResolverTest.php

@@ -87,6 +87,8 @@ class ControllerResolverTest extends BaseControllerResolverTest
 
     public function testGetControllerInvokableService()
     {
+        $invokableController = new InvokableController('bar');
+
         $container = $this->createMockContainer();
         $container->expects($this->once())
             ->method('has')
@@ -96,7 +98,7 @@ class ControllerResolverTest extends BaseControllerResolverTest
         $container->expects($this->once())
             ->method('get')
             ->with('foo')
-            ->will($this->returnValue($this))
+            ->will($this->returnValue($invokableController))
         ;
 
         $resolver = $this->createControllerResolver(null, null, $container);
@@ -105,7 +107,33 @@ class ControllerResolverTest extends BaseControllerResolverTest
 
         $controller = $resolver->getController($request);
 
-        $this->assertInstanceOf(get_class($this), $controller);
+        $this->assertEquals($invokableController, $controller);
+    }
+
+    public function testGetControllerInvokableServiceWithClassNameAsName()
+    {
+        $invokableController = new InvokableController('bar');
+        $className = __NAMESPACE__.'\InvokableController';
+
+        $container = $this->createMockContainer();
+        $container->expects($this->once())
+            ->method('has')
+            ->with($className)
+            ->will($this->returnValue(true))
+        ;
+        $container->expects($this->once())
+            ->method('get')
+            ->with($className)
+            ->will($this->returnValue($invokableController))
+        ;
+
+        $resolver = $this->createControllerResolver(null, null, $container);
+        $request = Request::create('/');
+        $request->attributes->set('_controller', $className);
+
+        $controller = $resolver->getController($request);
+
+        $this->assertEquals($invokableController, $controller);
     }
 
     /**
@@ -178,3 +206,14 @@ class ContainerAwareController implements ContainerAwareInterface
     {
     }
 }
+
+class InvokableController
+{
+    public function __construct($bar) // mandatory argument to prevent automatic instantiation
+    {
+    }
+
+    public function __invoke()
+    {
+    }
+}