diff --git a/CHANGELOG-4.0.md b/CHANGELOG-4.0.md
index fc1f989d485f7..f1c98b1874d2a 100644
--- a/CHANGELOG-4.0.md
+++ b/CHANGELOG-4.0.md
@@ -7,6 +7,32 @@ in 4.0 minor versions.
 To get the diff for a specific change, go to https://github.com/symfony/symfony/commit/XXX where XXX is the change hash
 To get the diff between two versions, go to https://github.com/symfony/symfony/compare/v4.0.0...v4.0.1
 
+* 4.0.0 (2017-11-30)
+
+ * bug #25220 [HttpFoundation] Add Session::isEmpty(), fix MockFileSessionStorage to behave like the native one (nicolas-grekas)
+ * bug #25209 [VarDumper] Dont use empty(), it chokes on eg GMP objects (nicolas-grekas)
+ * bug #25200 [HttpKernel] Arrays with scalar values passed to ESI fragment renderer throw deprecation notice (Simperfit)
+ * bug #25201 [HttpKernel] Add a better error messages when passing a private or non-tagged controller (Simperfit)
+ * bug #25155 [DependencyInjection] Detect case mismatch in autowiring (Simperfit, sroze)
+ * bug #25217 [Dotenv] Changed preg_match flags from null to 0 (deekthesqueak)
+ * bug #25180 [DI] Fix circular reference when using setters (nicolas-grekas)
+ * bug #25204 [DI] Clear service reference graph (nicolas-grekas)
+ * bug #25203 [DI] Fix infinite loop in InlineServiceDefinitionsPass (nicolas-grekas)
+ * bug #25185 [Serializer] Do not cache attributes if `attributes` in context (sroze)
+ * bug #25190 [HttpKernel] Keep legacy container files for concurrent requests (nicolas-grekas)
+ * bug #25182 [HttpFoundation] AutExpireFlashBag should not clear new flashes (Simperfit, sroze)
+ * bug #25174 [Translation] modify definitions only if the do exist (xabbuh)
+ * bug #25179 [FrameworkBundle][Serializer] Remove YamlEncoder definition if Yaml component isn't installed (ogizanagi)
+ * bug #25160 [DI] Prevent a ReflectionException during cache:clear when the parent class doesn't exist (dunglas)
+ * bug #25163 [DI] Fix tracking of env vars in exceptions (nicolas-grekas)
+ * bug #25162 [HttpKernel] Read $_ENV when checking SHELL_VERBOSITY (nicolas-grekas)
+ * bug #25158 [DI] Remove unreachable code (GawainLynch)
+ * bug #25152 [Form] Don't rely on `Symfony\Component\HttpFoundation\File\File` if http-foundation isn't in FileType (issei-m)
+ * bug #24987 [Console] Fix global console flag when used in chain (Simperfit)
+ * bug #25137 Adding checks for the expression language (weaverryan)
+ * bug #25151 [FrameworkBundle] Automatically enable the CSRF protection if CSRF manager exists (sroze)
+ * bug #25043 [Yaml] added ability for substitute aliases when mapping is on single line (Michał Strzelecki, xabbuh)
+
 * 4.0.0-RC2 (2017-11-24)
 
  * bug #25146 [DI] Dont resolve envs in service ids (nicolas-grekas)
diff --git a/UPGRADE-4.0.md b/UPGRADE-4.0.md
index 80451f5d61a4c..96c652705aa81 100644
--- a/UPGRADE-4.0.md
+++ b/UPGRADE-4.0.md
@@ -598,12 +598,6 @@ HttpKernel
            tags: ['console.command']
    ```
 
- * Removed the `kernel.root_dir` parameter. Use the `kernel.project_dir` parameter
-   instead.
-
- * Removed the `Kernel::getRootDir()` method. Use the `Kernel::getProjectDir()`
-   method instead.
-
  * The `Extension::addClassesToCompile()` and `Extension::getClassesToCompile()` methods have been removed.
 
  * Possibility to pass non-scalar values as URI attributes to the ESI and SSI
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index 5414790df4963..0f82e9c9e139f 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -21,6 +21,7 @@
 use Symfony\Component\Form\Form;
 use Symfony\Component\Lock\Lock;
 use Symfony\Component\Lock\Store\SemaphoreStore;
+use Symfony\Component\Security\Csrf\CsrfTokenManagerInterface;
 use Symfony\Component\Serializer\Serializer;
 use Symfony\Component\Translation\Translator;
 use Symfony\Component\Validator\Validation;
@@ -109,7 +110,7 @@ private function addCsrfSection(ArrayNodeDefinition $rootNode)
         $rootNode
             ->children()
                 ->arrayNode('csrf_protection')
-                    ->canBeEnabled()
+                    ->{!class_exists(FullStack::class) && class_exists(CsrfTokenManagerInterface::class) ? 'canBeDisabled' : 'canBeEnabled'}()
                 ->end()
             ->end()
         ;
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
index 4874b1bba3d2c..ec9010a16e576 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -74,6 +74,7 @@
 use Symfony\Component\WebLink\HttpHeaderSerializer;
 use Symfony\Component\Workflow;
 use Symfony\Component\Yaml\Command\LintCommand as BaseYamlLintCommand;
+use Symfony\Component\Yaml\Yaml;
 
 /**
  * FrameworkExtension.
@@ -1159,6 +1160,10 @@ private function registerSerializerConfiguration(array $config, ContainerBuilder
             $container->removeDefinition('serializer.normalizer.object');
         }
 
+        if (!class_exists(Yaml::class)) {
+            $container->removeDefinition('serializer.encoder.yaml');
+        }
+
         $serializerLoaders = array();
         if (isset($config['enable_annotations']) && $config['enable_annotations']) {
             if (!$this->annotationsConfigEnabled) {
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/Kernel/MicroKernelTraitTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/Kernel/MicroKernelTraitTest.php
index 2cb1ba8f7d67b..539306fcea2b9 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/Kernel/MicroKernelTraitTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/Kernel/MicroKernelTraitTest.php
@@ -18,7 +18,7 @@ class MicroKernelTraitTest extends TestCase
 {
     public function test()
     {
-        $kernel = new ConcreteMicroKernel('test', true);
+        $kernel = new ConcreteMicroKernel('test', false);
         $kernel->boot();
 
         $request = Request::create('/');
@@ -31,7 +31,7 @@ public function test()
 
     public function testAsEventSubscriber()
     {
-        $kernel = new ConcreteMicroKernel('test', true);
+        $kernel = new ConcreteMicroKernel('test', false);
         $kernel->boot();
 
         $request = Request::create('/danger');
diff --git a/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/AbstractFactory.php b/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/AbstractFactory.php
index d1b7980faa8a6..26fa75572cd9e 100644
--- a/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/AbstractFactory.php
+++ b/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/AbstractFactory.php
@@ -29,7 +29,7 @@ abstract class AbstractFactory implements SecurityFactoryInterface
     protected $options = array(
         'check_path' => '/login_check',
         'use_forward' => false,
-        'require_previous_session' => true,
+        'require_previous_session' => false,
     );
 
     protected $defaultSuccessHandlerOptions = array(
diff --git a/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/JsonLoginFactory.php b/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/JsonLoginFactory.php
index 28a7bf5743078..5a391ffacaeab 100644
--- a/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/JsonLoginFactory.php
+++ b/src/Symfony/Bundle/SecurityBundle/DependencyInjection/Security/Factory/JsonLoginFactory.php
@@ -28,7 +28,6 @@ public function __construct()
         $this->addOption('password_path', 'password');
         $this->defaultFailureHandlerOptions = array();
         $this->defaultSuccessHandlerOptions = array();
-        $this->options['require_previous_session'] = false;
     }
 
     /**
diff --git a/src/Symfony/Component/Console/Input/ArgvInput.php b/src/Symfony/Component/Console/Input/ArgvInput.php
index 4441296b7f1a7..df12d4d42ebb1 100644
--- a/src/Symfony/Component/Console/Input/ArgvInput.php
+++ b/src/Symfony/Component/Console/Input/ArgvInput.php
@@ -280,6 +280,14 @@ public function hasParameterOption($values, $onlyParams = false)
                 if ($token === $value || 0 === strpos($token, $value.'=')) {
                     return true;
                 }
+
+                if (0 === strpos($token, '-') && 0 !== strpos($token, '--')) {
+                    $searchableToken = str_replace('-', '', $token);
+                    $searchableValue = str_replace('-', '', $value);
+                    if ('' !== $searchableToken && '' !== $searchableValue && false !== strpos($searchableToken, $searchableValue)) {
+                        return true;
+                    }
+                }
             }
         }
 
diff --git a/src/Symfony/Component/Console/Tests/Input/ArgvInputTest.php b/src/Symfony/Component/Console/Tests/Input/ArgvInputTest.php
index 8287bce521d37..b9b42b9af4c3f 100644
--- a/src/Symfony/Component/Console/Tests/Input/ArgvInputTest.php
+++ b/src/Symfony/Component/Console/Tests/Input/ArgvInputTest.php
@@ -314,6 +314,9 @@ public function testHasParameterOption()
         $input = new ArgvInput(array('cli.php', '-f', 'foo'));
         $this->assertTrue($input->hasParameterOption('-f'), '->hasParameterOption() returns true if the given short option is in the raw input');
 
+        $input = new ArgvInput(array('cli.php', '-fh'));
+        $this->assertTrue($input->hasParameterOption('-fh'), '->hasParameterOption() returns true if the given short option is in the raw input');
+
         $input = new ArgvInput(array('cli.php', '--foo', 'foo'));
         $this->assertTrue($input->hasParameterOption('--foo'), '->hasParameterOption() returns true if the given short option is in the raw input');
 
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php b/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php
index afda55c94f21b..638669aa57646 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php
@@ -337,7 +337,10 @@ private function createTypeAlternatives(TypedReference $reference)
             return ' '.$message;
         }
 
-        if (isset($this->ambiguousServiceTypes[$type])) {
+        $servicesAndAliases = $this->container->getServiceIds();
+        if (!$this->container->has($type) && false !== $key = array_search(strtolower($type), array_map('strtolower', $servicesAndAliases))) {
+            return sprintf(' Did you mean "%s"?', $servicesAndAliases[$key]);
+        } elseif (isset($this->ambiguousServiceTypes[$type])) {
             $message = sprintf('one of these existing services: "%s"', implode('", "', $this->ambiguousServiceTypes[$type]));
         } elseif (isset($this->types[$type])) {
             $message = sprintf('the existing "%s" service', $this->types[$type]);
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/Compiler.php b/src/Symfony/Component/DependencyInjection/Compiler/Compiler.php
index abc6205a969b6..7c797a92b3d54 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/Compiler.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/Compiler.php
@@ -113,6 +113,8 @@ public function compile(ContainerBuilder $container)
             }
 
             throw $e;
+        } finally {
+            $this->getServiceReferenceGraph()->clear();
         }
     }
 }
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/InlineServiceDefinitionsPass.php b/src/Symfony/Component/DependencyInjection/Compiler/InlineServiceDefinitionsPass.php
index 76f2e502170de..8fdbd8e2b5681 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/InlineServiceDefinitionsPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/InlineServiceDefinitionsPass.php
@@ -47,10 +47,7 @@ protected function processValue($value, $isRoot = false)
             if ($this->isInlineableDefinition($id, $definition, $this->container->getCompiler()->getServiceReferenceGraph())) {
                 $this->container->log($this, sprintf('Inlined service "%s" to "%s".', $id, $this->currentId));
 
-                if ($definition->isShared()) {
-                    return $definition;
-                }
-                $value = clone $definition;
+                return $definition->isShared() ? $definition : clone $definition;
             }
         }
 
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/MergeExtensionConfigurationPass.php b/src/Symfony/Component/DependencyInjection/Compiler/MergeExtensionConfigurationPass.php
index b6fee88f4aeef..e077529b59185 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/MergeExtensionConfigurationPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/MergeExtensionConfigurationPass.php
@@ -56,18 +56,26 @@ public function process(ContainerBuilder $container)
             }
             $config = $resolvingBag->resolveValue($config);
 
-            $tmpContainer = new MergeExtensionConfigurationContainerBuilder($extension, $resolvingBag);
-            $tmpContainer->setResourceTracking($container->isTrackingResources());
-            $tmpContainer->addObjectResource($extension);
-            if ($extension instanceof ConfigurationExtensionInterface && null !== $configuration = $extension->getConfiguration($config, $tmpContainer)) {
-                $tmpContainer->addObjectResource($configuration);
-            }
+            try {
+                $tmpContainer = new MergeExtensionConfigurationContainerBuilder($extension, $resolvingBag);
+                $tmpContainer->setResourceTracking($container->isTrackingResources());
+                $tmpContainer->addObjectResource($extension);
+                if ($extension instanceof ConfigurationExtensionInterface && null !== $configuration = $extension->getConfiguration($config, $tmpContainer)) {
+                    $tmpContainer->addObjectResource($configuration);
+                }
 
-            foreach ($exprLangProviders as $provider) {
-                $tmpContainer->addExpressionLanguageProvider($provider);
-            }
+                foreach ($exprLangProviders as $provider) {
+                    $tmpContainer->addExpressionLanguageProvider($provider);
+                }
 
-            $extension->load($config, $tmpContainer);
+                $extension->load($config, $tmpContainer);
+            } catch (\Exception $e) {
+                if ($resolvingBag instanceof MergeExtensionConfigurationParameterBag) {
+                    $container->getParameterBag()->mergeEnvPlaceholders($resolvingBag);
+                }
+
+                throw $e;
+            }
 
             if ($resolvingBag instanceof MergeExtensionConfigurationParameterBag) {
                 // don't keep track of env vars that are *overridden* when configs are merged
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php b/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php
index 8c81452b315a6..f8dba86a0b547 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php
@@ -74,9 +74,6 @@ protected function processValue($value, $isRoot = false)
             if ($optionalBehavior = '?' === $type[0]) {
                 $type = substr($type, 1);
                 $optionalBehavior = ContainerInterface::IGNORE_ON_INVALID_REFERENCE;
-            } elseif ($optionalBehavior = '!' === $type[0]) {
-                $type = substr($type, 1);
-                $optionalBehavior = ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE;
             }
             if (is_int($key)) {
                 $key = $type;
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraph.php b/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraph.php
index 0474541f3d761..5a370398408dc 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraph.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraph.php
@@ -64,6 +64,9 @@ public function getNodes(): array
      */
     public function clear()
     {
+        foreach ($this->nodes as $node) {
+            $node->clear();
+        }
         $this->nodes = array();
     }
 
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraphNode.php b/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraphNode.php
index d655dba69a6a7..b7274c425b707 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraphNode.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/ServiceReferenceGraphNode.php
@@ -107,4 +107,12 @@ public function getValue()
     {
         return $this->value;
     }
+
+    /**
+     * Clears all edges.
+     */
+    public function clear()
+    {
+        $this->inEdges = $this->outEdges = array();
+    }
 }
diff --git a/src/Symfony/Component/DependencyInjection/ContainerBuilder.php b/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
index 3707b163d0dcd..7ee66c05f015b 100644
--- a/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
+++ b/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
@@ -519,6 +519,14 @@ public function has($id)
      */
     public function get($id, $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE)
     {
+        return $this->doGet($id, $invalidBehavior);
+    }
+
+    private function doGet($id, $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE, array &$inlineServices = array())
+    {
+        if (isset($inlineServices[$id])) {
+            return $inlineServices[$id];
+        }
         if (ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE === $invalidBehavior) {
             return parent::get($id, $invalidBehavior);
         }
@@ -527,7 +535,7 @@ public function get($id, $invalidBehavior = ContainerInterface::EXCEPTION_ON_INV
         }
 
         if (!isset($this->definitions[$id]) && isset($this->aliasDefinitions[$id])) {
-            return $this->get((string) $this->aliasDefinitions[$id], $invalidBehavior);
+            return $this->doGet((string) $this->aliasDefinitions[$id], $invalidBehavior, $inlineServices);
         }
 
         try {
@@ -544,7 +552,7 @@ public function get($id, $invalidBehavior = ContainerInterface::EXCEPTION_ON_INV
         $this->{$loading}[$id] = true;
 
         try {
-            $service = $this->createService($definition, new \SplObjectStorage(), $id);
+            $service = $this->createService($definition, $inlineServices, $id);
         } finally {
             unset($this->{$loading}[$id]);
         }
@@ -978,10 +986,10 @@ public function findDefinition($id)
      * @throws RuntimeException         When the service is a synthetic service
      * @throws InvalidArgumentException When configure callable is not callable
      */
-    private function createService(Definition $definition, \SplObjectStorage $inlinedDefinitions, $id = null, $tryProxy = true)
+    private function createService(Definition $definition, array &$inlineServices, $id = null, $tryProxy = true)
     {
-        if (null === $id && isset($inlinedDefinitions[$definition])) {
-            return $inlinedDefinitions[$definition];
+        if (null === $id && isset($inlineServices[$h = spl_object_hash($definition)])) {
+            return $inlineServices[$h];
         }
 
         if ($definition instanceof ChildDefinition) {
@@ -1002,11 +1010,11 @@ private function createService(Definition $definition, \SplObjectStorage $inline
                 ->instantiateProxy(
                     $this,
                     $definition,
-                    $id, function () use ($definition, $inlinedDefinitions, $id) {
-                        return $this->createService($definition, $inlinedDefinitions, $id, false);
+                    $id, function () use ($definition, &$inlineServices, $id) {
+                        return $this->createService($definition, $inlineServices, $id, false);
                     }
                 );
-            $this->shareService($definition, $proxy, $id, $inlinedDefinitions);
+            $this->shareService($definition, $proxy, $id, $inlineServices);
 
             return $proxy;
         }
@@ -1017,7 +1025,7 @@ private function createService(Definition $definition, \SplObjectStorage $inline
             require_once $parameterBag->resolveValue($definition->getFile());
         }
 
-        $arguments = $this->doResolveServices($parameterBag->unescapeValue($parameterBag->resolveValue($definition->getArguments())), $inlinedDefinitions);
+        $arguments = $this->doResolveServices($parameterBag->unescapeValue($parameterBag->resolveValue($definition->getArguments())), $inlineServices);
 
         if (null !== $id && $definition->isShared() && isset($this->services[$id]) && ($tryProxy || !$definition->isLazy())) {
             return $this->services[$id];
@@ -1025,7 +1033,7 @@ private function createService(Definition $definition, \SplObjectStorage $inline
 
         if (null !== $factory = $definition->getFactory()) {
             if (is_array($factory)) {
-                $factory = array($this->doResolveServices($parameterBag->resolveValue($factory[0]), $inlinedDefinitions), $factory[1]);
+                $factory = array($this->doResolveServices($parameterBag->resolveValue($factory[0]), $inlineServices), $factory[1]);
             } elseif (!is_string($factory)) {
                 throw new RuntimeException(sprintf('Cannot create service "%s" because of invalid factory', $id));
             }
@@ -1051,16 +1059,16 @@ private function createService(Definition $definition, \SplObjectStorage $inline
 
         if ($tryProxy || !$definition->isLazy()) {
             // share only if proxying failed, or if not a proxy
-            $this->shareService($definition, $service, $id, $inlinedDefinitions);
+            $this->shareService($definition, $service, $id, $inlineServices);
         }
 
-        $properties = $this->doResolveServices($parameterBag->unescapeValue($parameterBag->resolveValue($definition->getProperties())), $inlinedDefinitions);
+        $properties = $this->doResolveServices($parameterBag->unescapeValue($parameterBag->resolveValue($definition->getProperties())), $inlineServices);
         foreach ($properties as $name => $value) {
             $service->$name = $value;
         }
 
         foreach ($definition->getMethodCalls() as $call) {
-            $this->callMethod($service, $call, $inlinedDefinitions);
+            $this->callMethod($service, $call, $inlineServices);
         }
 
         if ($callable = $definition->getConfigurator()) {
@@ -1068,9 +1076,9 @@ private function createService(Definition $definition, \SplObjectStorage $inline
                 $callable[0] = $parameterBag->resolveValue($callable[0]);
 
                 if ($callable[0] instanceof Reference) {
-                    $callable[0] = $this->get((string) $callable[0], $callable[0]->getInvalidBehavior());
+                    $callable[0] = $this->doGet((string) $callable[0], $callable[0]->getInvalidBehavior(), $inlineServices);
                 } elseif ($callable[0] instanceof Definition) {
-                    $callable[0] = $this->createService($callable[0], $inlinedDefinitions);
+                    $callable[0] = $this->createService($callable[0], $inlineServices);
                 }
             }
 
@@ -1094,14 +1102,14 @@ private function createService(Definition $definition, \SplObjectStorage $inline
      */
     public function resolveServices($value)
     {
-        return $this->doResolveServices($value, new \SplObjectStorage());
+        return $this->doResolveServices($value);
     }
 
-    private function doResolveServices($value, \SplObjectStorage $inlinedDefinitions)
+    private function doResolveServices($value, array &$inlineServices = array())
     {
         if (is_array($value)) {
             foreach ($value as $k => $v) {
-                $value[$k] = $this->doResolveServices($v, $inlinedDefinitions);
+                $value[$k] = $this->doResolveServices($v, $inlineServices);
             }
         } elseif ($value instanceof ServiceClosureArgument) {
             $reference = $value->getValues()[0];
@@ -1117,7 +1125,7 @@ private function doResolveServices($value, \SplObjectStorage $inlinedDefinitions
                         }
                     }
                     foreach (self::getInitializedConditionals($v) as $s) {
-                        if (!$this->get($s, ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE)) {
+                        if (!$this->doGet($s, ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE)) {
                             continue 2;
                         }
                     }
@@ -1133,7 +1141,7 @@ private function doResolveServices($value, \SplObjectStorage $inlinedDefinitions
                         }
                     }
                     foreach (self::getInitializedConditionals($v) as $s) {
-                        if (!$this->get($s, ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE)) {
+                        if (!$this->doGet($s, ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE)) {
                             continue 2;
                         }
                     }
@@ -1144,9 +1152,9 @@ private function doResolveServices($value, \SplObjectStorage $inlinedDefinitions
                 return $count;
             });
         } elseif ($value instanceof Reference) {
-            $value = $this->get((string) $value, $value->getInvalidBehavior());
+            $value = $this->doGet((string) $value, $value->getInvalidBehavior(), $inlineServices);
         } elseif ($value instanceof Definition) {
-            $value = $this->createService($value, $inlinedDefinitions);
+            $value = $this->createService($value, $inlineServices);
         } elseif ($value instanceof Expression) {
             $value = $this->getExpressionLanguage()->evaluate($value, array('container' => $this));
         }
@@ -1443,7 +1451,7 @@ private function getProxyInstantiator(): InstantiatorInterface
         return $this->proxyInstantiator;
     }
 
-    private function callMethod($service, $call, \SplObjectStorage $inlinedDefinitions)
+    private function callMethod($service, $call, array &$inlineServices)
     {
         foreach (self::getServiceConditionals($call[1]) as $s) {
             if (!$this->has($s)) {
@@ -1451,12 +1459,12 @@ private function callMethod($service, $call, \SplObjectStorage $inlinedDefinitio
             }
         }
         foreach (self::getInitializedConditionals($call[1]) as $s) {
-            if (!$this->get($s, ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE)) {
+            if (!$this->doGet($s, ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE, $inlineServices)) {
                 return;
             }
         }
 
-        call_user_func_array(array($service, $call[0]), $this->doResolveServices($this->getParameterBag()->unescapeValue($this->getParameterBag()->resolveValue($call[1])), $inlinedDefinitions));
+        call_user_func_array(array($service, $call[0]), $this->doResolveServices($this->getParameterBag()->unescapeValue($this->getParameterBag()->resolveValue($call[1])), $inlineServices));
     }
 
     /**
@@ -1466,14 +1474,11 @@ private function callMethod($service, $call, \SplObjectStorage $inlinedDefinitio
      * @param object      $service
      * @param string|null $id
      */
-    private function shareService(Definition $definition, $service, $id, \SplObjectStorage $inlinedDefinitions)
+    private function shareService(Definition $definition, $service, $id, array &$inlineServices)
     {
-        if (!$definition->isShared()) {
-            return;
-        }
-        if (null === $id) {
-            $inlinedDefinitions[$definition] = $service;
-        } else {
+        $inlineServices[null !== $id ? $id : spl_object_hash($definition)] = $service;
+
+        if (null !== $id && $definition->isShared()) {
             $this->services[$id] = $service;
             unset($this->loading[$id], $this->alreadyLoading[$id]);
         }
diff --git a/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php b/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
index baf9613d841ad..f6204169bd96f 100644
--- a/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
+++ b/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
@@ -52,7 +52,6 @@ class PhpDumper extends Dumper
      */
     const NON_FIRST_CHARS = 'abcdefghijklmnopqrstuvwxyz0123456789_';
 
-    private $inlinedDefinitions;
     private $definitionVariables;
     private $referenceVariables;
     private $variableCount;
@@ -85,8 +84,6 @@ public function __construct(ContainerBuilder $container)
         }
 
         parent::__construct($container);
-
-        $this->inlinedDefinitions = new \SplObjectStorage();
     }
 
     /**
@@ -143,6 +140,7 @@ public function dump(array $options = array())
             $currentPath = array($id => $id);
             $this->analyzeCircularReferences($node->getOutEdges(), $checkedNodes, $currentPath);
         }
+        $this->container->getCompiler()->getServiceReferenceGraph()->clear();
 
         $this->docStar = $options['debug'] ? '*' : '';
 
@@ -272,54 +270,46 @@ private function getProxyDumper(): ProxyDumper
         return $this->proxyDumper;
     }
 
-    private function addServiceLocalTempVariables(string $cId, Definition $definition, array $inlinedDefinitions): string
+    private function addServiceLocalTempVariables(string $cId, Definition $definition, \SplObjectStorage $inlinedDefinitions, \SplObjectStorage $allInlinedDefinitions): string
     {
-        static $template = "        \$%s = %s;\n";
+        $allCalls = $calls = $behavior = array();
 
-        array_unshift($inlinedDefinitions, $definition);
+        foreach ($allInlinedDefinitions as $def) {
+            $arguments = array($def->getArguments(), $def->getFactory(), $def->getProperties(), $def->getMethodCalls(), $def->getConfigurator());
+            $this->getServiceCallsFromArguments($arguments, $allCalls, false, $cId, $behavior, $allInlinedDefinitions[$def]);
+        }
 
-        $collectLineage = $this->inlineRequires && !$this->isHotPath($definition);
-        $isNonLazyShared = isset($this->circularReferences[$cId]) && !$this->getProxyDumper()->isProxyCandidate($definition) && $definition->isShared();
-        $lineage = $calls = $behavior = array();
-        foreach ($inlinedDefinitions as $iDefinition) {
-            if ($collectLineage && !$iDefinition->isDeprecated() && $class = is_array($factory = $iDefinition->getFactory()) && is_string($factory[0]) ? $factory[0] : $iDefinition->getClass()) {
-                $this->collectLineage($class, $lineage);
+        $isPreInstance = isset($inlinedDefinitions[$definition]) && isset($this->circularReferences[$cId]) && !$this->getProxyDumper()->isProxyCandidate($definition) && $definition->isShared();
+        foreach ($inlinedDefinitions as $def) {
+            $this->getServiceCallsFromArguments(array($def->getArguments(), $def->getFactory()), $calls, $isPreInstance, $cId);
+            if ($def !== $definition) {
+                $arguments = array($def->getProperties(), $def->getMethodCalls(), $def->getConfigurator());
+                $this->getServiceCallsFromArguments($arguments, $calls, $isPreInstance && !$this->hasReference($cId, $arguments, true), $cId);
             }
-            $this->getServiceCallsFromArguments($iDefinition->getArguments(), $calls, $behavior, $isNonLazyShared, $cId);
-            $isPreInstantiation = $isNonLazyShared && $iDefinition !== $definition && !$this->hasReference($cId, $iDefinition->getMethodCalls(), true) && !$this->hasReference($cId, $iDefinition->getProperties(), true);
-            $this->getServiceCallsFromArguments($iDefinition->getMethodCalls(), $calls, $behavior, $isPreInstantiation, $cId);
-            $this->getServiceCallsFromArguments($iDefinition->getProperties(), $calls, $behavior, $isPreInstantiation, $cId);
-            $this->getServiceCallsFromArguments(array($iDefinition->getConfigurator()), $calls, $behavior, $isPreInstantiation, $cId);
-            $this->getServiceCallsFromArguments(array($iDefinition->getFactory()), $calls, $behavior, $isNonLazyShared, $cId);
+        }
+        if (!isset($inlinedDefinitions[$definition])) {
+            $arguments = array($definition->getProperties(), $definition->getMethodCalls(), $definition->getConfigurator());
+            $this->getServiceCallsFromArguments($arguments, $calls, false, $cId);
         }
 
         $code = '';
         foreach ($calls as $id => $callCount) {
-            if ('service_container' === $id || $id === $cId) {
+            if ('service_container' === $id || $id === $cId || isset($this->referenceVariables[$id])) {
                 continue;
             }
-
-            if ($collectLineage && ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE !== $behavior[$id] && $this->container->has($id)
-                && $this->isTrivialInstance($iDefinition = $this->container->findDefinition($id))
-                && $class = is_array($factory = $iDefinition->getFactory()) && is_string($factory[0]) ? $factory[0] : $iDefinition->getClass()
-            ) {
-                $this->collectLineage($class, $lineage);
+            if ($callCount <= 1 && $allCalls[$id] <= 1) {
+                continue;
             }
 
-            if ($callCount > 1) {
-                $name = $this->getNextVariableName();
-                $this->referenceVariables[$id] = new Variable($name);
+            $name = $this->getNextVariableName();
+            $this->referenceVariables[$id] = new Variable($name);
 
-                if (ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE === $behavior[$id]) {
-                    $code .= sprintf($template, $name, $this->getServiceCall($id));
-                } else {
-                    $code .= sprintf($template, $name, $this->getServiceCall($id, new Reference($id, $behavior[$id])));
-                }
-            }
+            $reference = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE === $behavior[$id] ? new Reference($id, $behavior[$id]) : null;
+            $code .= sprintf("        \$%s = %s;\n", $name, $this->getServiceCall($id, $reference));
         }
 
         if ('' !== $code) {
-            if ($isNonLazyShared) {
+            if ($isPreInstance) {
                 $code .= sprintf(<<<'EOTXT'
 
         if (isset($this->%s['%s'])) {
@@ -333,14 +323,6 @@ private function addServiceLocalTempVariables(string $cId, Definition $definitio
             $code .= "\n";
         }
 
-        if ($lineage && $lineage = array_diff_key(array_flip($lineage), $this->inlinedRequires)) {
-            $code = "\n".$code;
-
-            foreach (array_reverse($lineage) as $file => $class) {
-                $code = sprintf("        require_once %s;\n", $file).$code;
-            }
-        }
-
         return $code;
     }
 
@@ -350,11 +332,6 @@ private function analyzeCircularReferences(array $edges, &$checkedNodes, &$curre
             $node = $edge->getDestNode();
             $id = $node->getId();
 
-            if (isset($checkedNodes[$id])) {
-                continue;
-            }
-            $checkedNodes[$id] = true;
-
             if ($node->getValue() && ($edge->isLazy() || $edge->isWeak())) {
                 // no-op
             } elseif (isset($currentPath[$id])) {
@@ -362,10 +339,11 @@ private function analyzeCircularReferences(array $edges, &$checkedNodes, &$curre
                     $this->circularReferences[$parentId][$id] = $id;
                     $id = $parentId;
                 }
-            } else {
+            } elseif (!isset($checkedNodes[$id])) {
+                $checkedNodes[$id] = true;
                 $currentPath[$id] = $id;
                 $this->analyzeCircularReferences($node->getOutEdges(), $checkedNodes, $currentPath);
-                array_pop($currentPath);
+                unset($currentPath[$id]);
             }
         }
     }
@@ -375,7 +353,7 @@ private function collectLineage($class, array &$lineage)
         if (isset($lineage[$class])) {
             return;
         }
-        if (!$r = $this->container->getReflectionClass($class)) {
+        if (!$r = $this->container->getReflectionClass($class, false)) {
             return;
         }
         if ($this->container instanceof $class) {
@@ -420,18 +398,39 @@ private function generateProxyClasses()
         }
     }
 
-    private function addServiceInclude(Definition $definition, array $inlinedDefinitions): string
+    private function addServiceInclude(string $cId, Definition $definition, \SplObjectStorage $inlinedDefinitions): string
     {
-        $template = "        require_once %s;\n";
         $code = '';
 
-        if (null !== $file = $definition->getFile()) {
-            $code .= sprintf($template, $this->dumpValue($file));
+        if ($this->inlineRequires && !$this->isHotPath($definition)) {
+            $lineage = $calls = $behavior = array();
+            foreach ($inlinedDefinitions as $def) {
+                if (!$def->isDeprecated() && $class = is_array($factory = $def->getFactory()) && is_string($factory[0]) ? $factory[0] : $def->getClass()) {
+                    $this->collectLineage($class, $lineage);
+                }
+                $arguments = array($def->getArguments(), $def->getFactory(), $def->getProperties(), $def->getMethodCalls(), $def->getConfigurator());
+                $this->getServiceCallsFromArguments($arguments, $calls, false, $cId, $behavior, $inlinedDefinitions[$def]);
+            }
+
+            foreach ($calls as $id => $callCount) {
+                if ('service_container' !== $id && $id !== $cId
+                    && ContainerInterface::IGNORE_ON_UNINITIALIZED_REFERENCE !== $behavior[$id]
+                    && $this->container->has($id)
+                    && $this->isTrivialInstance($def = $this->container->findDefinition($id))
+                    && $class = is_array($factory = $def->getFactory()) && is_string($factory[0]) ? $factory[0] : $def->getClass()
+                ) {
+                    $this->collectLineage($class, $lineage);
+                }
+            }
+
+            foreach (array_diff_key(array_flip($lineage), $this->inlinedRequires) as $file => $class) {
+                $code .= sprintf("        require_once %s;\n", $file);
+            }
         }
 
-        foreach ($inlinedDefinitions as $definition) {
-            if (null !== $file = $definition->getFile()) {
-                $code .= sprintf($template, $this->dumpValue($file));
+        foreach ($inlinedDefinitions as $def) {
+            if ($file = $def->getFile()) {
+                $code .= sprintf("        require_once %s;\n", $this->dumpValue($file));
             }
         }
 
@@ -448,54 +447,46 @@ private function addServiceInclude(Definition $definition, array $inlinedDefinit
      * @throws RuntimeException                  When the factory definition is incomplete
      * @throws ServiceCircularReferenceException When a circular reference is detected
      */
-    private function addServiceInlinedDefinitions(string $id, array $inlinedDefinitions): string
+    private function addServiceInlinedDefinitions(string $id, Definition $definition, \SplObjectStorage $inlinedDefinitions, bool &$isSimpleInstance): string
     {
         $code = '';
-        $variableMap = $this->definitionVariables;
-        $nbOccurrences = new \SplObjectStorage();
-        $processed = new \SplObjectStorage();
 
-        foreach ($inlinedDefinitions as $definition) {
-            if (false === $nbOccurrences->contains($definition)) {
-                $nbOccurrences->offsetSet($definition, 1);
-            } else {
-                $i = $nbOccurrences->offsetGet($definition);
-                $nbOccurrences->offsetSet($definition, $i + 1);
+        foreach ($inlinedDefinitions as $def) {
+            if ($definition === $def) {
+                continue;
             }
-        }
-
-        foreach ($inlinedDefinitions as $sDefinition) {
-            if ($processed->contains($sDefinition)) {
+            if ($inlinedDefinitions[$def] <= 1 && !$def->getMethodCalls() && !$def->getProperties() && !$def->getConfigurator() && false === strpos($this->dumpValue($def->getClass()), '$')) {
                 continue;
             }
-            $processed->offsetSet($sDefinition);
-
-            $class = $this->dumpValue($sDefinition->getClass());
-            if ($nbOccurrences->offsetGet($sDefinition) > 1 || $sDefinition->getMethodCalls() || $sDefinition->getProperties() || null !== $sDefinition->getConfigurator() || false !== strpos($class, '$')) {
+            if (isset($this->definitionVariables[$def])) {
+                $name = $this->definitionVariables[$def];
+            } else {
                 $name = $this->getNextVariableName();
-                $variableMap->offsetSet($sDefinition, new Variable($name));
-
-                // a construct like:
-                // $a = new ServiceA(ServiceB $b); $b = new ServiceB(ServiceA $a);
-                // this is an indication for a wrong implementation, you can circumvent this problem
-                // by setting up your service structure like this:
-                // $b = new ServiceB();
-                // $a = new ServiceA(ServiceB $b);
-                // $b->setServiceA(ServiceA $a);
-                if ($this->hasReference($id, $sDefinition->getArguments())) {
-                    throw new ServiceCircularReferenceException($id, array($id));
-                }
+                $this->definitionVariables[$def] = new Variable($name);
+            }
 
-                $code .= $this->addNewInstance($sDefinition, '$'.$name, ' = ', $id);
+            // a construct like:
+            // $a = new ServiceA(ServiceB $b); $b = new ServiceB(ServiceA $a);
+            // this is an indication for a wrong implementation, you can circumvent this problem
+            // by setting up your service structure like this:
+            // $b = new ServiceB();
+            // $a = new ServiceA(ServiceB $b);
+            // $b->setServiceA(ServiceA $a);
+            if ($this->hasReference($id, array($def->getArguments(), $def->getFactory()))) {
+                throw new ServiceCircularReferenceException($id, array($id));
+            }
 
-                if (!$this->hasReference($id, $sDefinition->getMethodCalls(), true) && !$this->hasReference($id, $sDefinition->getProperties(), true)) {
-                    $code .= $this->addServiceProperties($sDefinition, $name);
-                    $code .= $this->addServiceMethodCalls($sDefinition, $name);
-                    $code .= $this->addServiceConfigurator($sDefinition, $name);
-                }
+            $code .= $this->addNewInstance($def, '$'.$name, ' = ', $id);
 
-                $code .= "\n";
+            if (!$this->hasReference($id, array($def->getProperties(), $def->getMethodCalls(), $def->getConfigurator()), true)) {
+                $code .= $this->addServiceProperties($def, $name);
+                $code .= $this->addServiceMethodCalls($def, $name);
+                $code .= $this->addServiceConfigurator($def, $name);
+            } else {
+                $isSimpleInstance = false;
             }
+
+            $code .= "\n";
         }
 
         return $code;
@@ -538,21 +529,6 @@ private function addServiceInstance(string $id, Definition $definition, string $
         return $code;
     }
 
-    private function isSimpleInstance(string $id, Definition $definition, array $inlinedDefinitions): bool
-    {
-        foreach (array_merge(array($definition), $inlinedDefinitions) as $sDefinition) {
-            if ($definition !== $sDefinition && !$this->hasReference($id, $sDefinition->getMethodCalls())) {
-                continue;
-            }
-
-            if ($sDefinition->getMethodCalls() || $sDefinition->getProperties() || $sDefinition->getConfigurator()) {
-                return false;
-            }
-        }
-
-        return true;
-    }
-
     private function isTrivialInstance(Definition $definition): bool
     {
         if ($definition->isSynthetic() || $definition->getFile() || $definition->getMethodCalls() || $definition->getProperties() || $definition->getConfigurator()) {
@@ -623,19 +599,13 @@ private function addServiceProperties(Definition $definition, $variableName = 'i
     /**
      * @throws ServiceCircularReferenceException when the container contains a circular reference
      */
-    private function addServiceInlinedDefinitionsSetup(string $id, array $inlinedDefinitions, bool $isSimpleInstance): string
+    private function addServiceInlinedDefinitionsSetup(string $id, Definition $definition, \SplObjectStorage $inlinedDefinitions, bool $isSimpleInstance): string
     {
         $this->referenceVariables[$id] = new Variable('instance');
 
         $code = '';
-        $processed = new \SplObjectStorage();
-        foreach ($inlinedDefinitions as $iDefinition) {
-            if ($processed->contains($iDefinition)) {
-                continue;
-            }
-            $processed->offsetSet($iDefinition);
-
-            if (!$this->hasReference($id, $iDefinition->getMethodCalls(), true) && !$this->hasReference($id, $iDefinition->getProperties(), true)) {
+        foreach ($inlinedDefinitions as $def) {
+            if ($definition === $def || !$this->hasReference($id, array($def->getProperties(), $def->getMethodCalls(), $def->getConfigurator()), true)) {
                 continue;
             }
 
@@ -645,13 +615,13 @@ private function addServiceInlinedDefinitionsSetup(string $id, array $inlinedDef
                 throw new ServiceCircularReferenceException($id, array($id));
             }
 
-            $name = (string) $this->definitionVariables->offsetGet($iDefinition);
-            $code .= $this->addServiceProperties($iDefinition, $name);
-            $code .= $this->addServiceMethodCalls($iDefinition, $name);
-            $code .= $this->addServiceConfigurator($iDefinition, $name);
+            $name = (string) $this->definitionVariables[$def];
+            $code .= $this->addServiceProperties($def, $name);
+            $code .= $this->addServiceMethodCalls($def, $name);
+            $code .= $this->addServiceConfigurator($def, $name);
         }
 
-        if ('' !== $code) {
+        if ('' !== $code && ($definition->getProperties() || $definition->getMethodCalls() || $definition->getConfigurator())) {
             $code .= "\n";
         }
 
@@ -759,15 +729,28 @@ protected function {$methodName}($lazyInitialization)
             $code .= sprintf("        @trigger_error(%s, E_USER_DEPRECATED);\n\n", $this->export($definition->getDeprecationMessage($id)));
         }
 
-        $inlinedDefinitions = $this->getInlinedDefinitions($definition);
-        $isSimpleInstance = $this->isSimpleInstance($id, $definition, $inlinedDefinitions);
+        $inlinedDefinitions = $this->getDefinitionsFromArguments(array($definition));
+        $constructorDefinitions = $this->getDefinitionsFromArguments(array($definition->getArguments(), $definition->getFactory()));
+        $otherDefinitions = new \SplObjectStorage();
+
+        foreach ($inlinedDefinitions as $def) {
+            if ($def === $definition || isset($constructorDefinitions[$def])) {
+                $constructorDefinitions[$def] = $inlinedDefinitions[$def];
+            } else {
+                $otherDefinitions[$def] = $inlinedDefinitions[$def];
+            }
+        }
+
+        $isSimpleInstance = !$definition->getProperties() && !$definition->getMethodCalls() && !$definition->getConfigurator();
 
         $code .=
-            $this->addServiceInclude($definition, $inlinedDefinitions).
-            $this->addServiceLocalTempVariables($id, $definition, $inlinedDefinitions).
-            $this->addServiceInlinedDefinitions($id, $inlinedDefinitions).
+            $this->addServiceInclude($id, $definition, $inlinedDefinitions).
+            $this->addServiceLocalTempVariables($id, $definition, $constructorDefinitions, $inlinedDefinitions).
+            $this->addServiceInlinedDefinitions($id, $definition, $constructorDefinitions, $isSimpleInstance).
             $this->addServiceInstance($id, $definition, $isSimpleInstance).
-            $this->addServiceInlinedDefinitionsSetup($id, $inlinedDefinitions, $isSimpleInstance).
+            $this->addServiceLocalTempVariables($id, $definition, $otherDefinitions, $inlinedDefinitions).
+            $this->addServiceInlinedDefinitions($id, $definition, $otherDefinitions, $isSimpleInstance).
+            $this->addServiceInlinedDefinitionsSetup($id, $definition, $inlinedDefinitions, $isSimpleInstance).
             $this->addServiceProperties($definition).
             $this->addServiceMethodCalls($definition).
             $this->addServiceConfigurator($definition).
@@ -1085,11 +1068,10 @@ private function addInlineRequires() :string
 
         foreach ($this->container->findTaggedServiceIds($this->hotPathTag) as $id => $tags) {
             $definition = $this->container->getDefinition($id);
-            $inlinedDefinitions = $this->getInlinedDefinitions($definition);
-            array_unshift($inlinedDefinitions, $definition);
+            $inlinedDefinitions = $this->getDefinitionsFromArguments(array($definition));
 
-            foreach ($inlinedDefinitions as $iDefinition) {
-                if ($class = is_array($factory = $iDefinition->getFactory()) && is_string($factory[0]) ? $factory[0] : $iDefinition->getClass()) {
+            foreach ($inlinedDefinitions as $def) {
+                if ($class = is_array($factory = $def->getFactory()) && is_string($factory[0]) ? $factory[0] : $def->getClass()) {
                     $this->collectLineage($class, $lineage);
                 }
             }
@@ -1298,16 +1280,16 @@ private function getServiceConditionals($value): string
         return implode(' && ', $conditions);
     }
 
-    private function getServiceCallsFromArguments(array $arguments, array &$calls, array &$behavior, bool $isPreInstantiation, string $callerId)
+    private function getServiceCallsFromArguments(array $arguments, array &$calls, bool $isPreInstance, string $callerId, array &$behavior = array(), int $step = 1)
     {
         foreach ($arguments as $argument) {
             if (is_array($argument)) {
-                $this->getServiceCallsFromArguments($argument, $calls, $behavior, $isPreInstantiation, $callerId);
+                $this->getServiceCallsFromArguments($argument, $calls, $isPreInstance, $callerId, $behavior, $step);
             } elseif ($argument instanceof Reference) {
                 $id = (string) $argument;
 
                 if (!isset($calls[$id])) {
-                    $calls[$id] = (int) ($isPreInstantiation && isset($this->circularReferences[$callerId][$id]));
+                    $calls[$id] = (int) ($isPreInstance && isset($this->circularReferences[$callerId][$id]));
                 }
                 if (!isset($behavior[$id])) {
                     $behavior[$id] = $argument->getInvalidBehavior();
@@ -1315,42 +1297,35 @@ private function getServiceCallsFromArguments(array $arguments, array &$calls, a
                     $behavior[$id] = min($behavior[$id], $argument->getInvalidBehavior());
                 }
 
-                ++$calls[$id];
+                $calls[$id] += $step;
             }
         }
     }
 
-    private function getInlinedDefinitions(Definition $definition): array
+    private function getDefinitionsFromArguments(array $arguments, \SplObjectStorage $definitions = null): \SplObjectStorage
     {
-        if (false === $this->inlinedDefinitions->contains($definition)) {
-            $definitions = array_merge(
-                $this->getDefinitionsFromArguments($definition->getArguments()),
-                $this->getDefinitionsFromArguments($definition->getMethodCalls()),
-                $this->getDefinitionsFromArguments($definition->getProperties()),
-                $this->getDefinitionsFromArguments(array($definition->getConfigurator())),
-                $this->getDefinitionsFromArguments(array($definition->getFactory()))
-            );
-
-            $this->inlinedDefinitions->offsetSet($definition, $definitions);
-
-            return $definitions;
+        if (null === $definitions) {
+            $definitions = new \SplObjectStorage();
         }
 
-        return $this->inlinedDefinitions->offsetGet($definition);
-    }
-
-    private function getDefinitionsFromArguments(array $arguments): array
-    {
-        $definitions = array();
         foreach ($arguments as $argument) {
             if (is_array($argument)) {
-                $definitions = array_merge($definitions, $this->getDefinitionsFromArguments($argument));
-            } elseif ($argument instanceof Definition) {
-                $definitions = array_merge(
-                    $definitions,
-                    $this->getInlinedDefinitions($argument),
-                    array($argument)
-                );
+                $this->getDefinitionsFromArguments($argument, $definitions);
+            } elseif (!$argument instanceof Definition) {
+                // no-op
+            } elseif (isset($definitions[$argument])) {
+                $definitions[$argument] = 1 + $definitions[$argument];
+            } else {
+                $definitions[$argument] = 1;
+                $this->getDefinitionsFromArguments($argument->getArguments(), $definitions);
+                $this->getDefinitionsFromArguments(array($argument->getFactory()), $definitions);
+                $this->getDefinitionsFromArguments($argument->getProperties(), $definitions);
+                $this->getDefinitionsFromArguments($argument->getMethodCalls(), $definitions);
+                $this->getDefinitionsFromArguments(array($argument->getConfigurator()), $definitions);
+                // move current definition last in the list
+                $nbOccurences = $definitions[$argument];
+                unset($definitions[$argument]);
+                $definitions[$argument] = $nbOccurences;
             }
         }
 
@@ -1395,9 +1370,7 @@ private function hasReference(string $id, array $arguments, bool $deep = false,
                 continue;
             }
 
-            $arguments = array_merge($service->getMethodCalls(), $service->getArguments(), $service->getProperties());
-
-            if ($this->hasReference($id, $arguments, $deep, $visited)) {
+            if ($this->hasReference($id, array($service->getArguments(), $service->getFactory(), $service->getProperties(), $service->getMethodCalls(), $service->getConfigurator()), $deep, $visited)) {
                 return true;
             }
         }
@@ -1473,7 +1446,7 @@ private function dumpValue($value, bool $interpolate = true): string
             }
         } elseif ($value instanceof Definition) {
             if (null !== $this->definitionVariables && $this->definitionVariables->contains($value)) {
-                return $this->dumpValue($this->definitionVariables->offsetGet($value), $interpolate);
+                return $this->dumpValue($this->definitionVariables[$value], $interpolate);
             }
             if ($value->getMethodCalls()) {
                 throw new RuntimeException('Cannot dump definitions which have method calls.');
diff --git a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
index a7e6ed4bf042a..26bed7d91e602 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
@@ -488,6 +488,10 @@ private function getArgumentsAsPhp(\DOMElement $node, $name, $file, $lowercase =
                     $arguments[$key] = new Reference($arg->getAttribute('id'), $invalidBehavior);
                     break;
                 case 'expression':
+                    if (!class_exists(Expression::class)) {
+                        throw new \LogicException(sprintf('The type="expression" attribute cannot be used without the ExpressionLanguage component. Try running "composer require symfony/expression-language".'));
+                    }
+
                     $arguments[$key] = new Expression($arg->nodeValue);
                     break;
                 case 'collection':
diff --git a/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
index 346531bc6a952..2e225aa05d627 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
@@ -727,6 +727,10 @@ private function resolveServices($value, $file, $isParameter = false)
                 $value[$k] = $this->resolveServices($v, $file, $isParameter);
             }
         } elseif (is_string($value) && 0 === strpos($value, '@=')) {
+            if (!class_exists(Expression::class)) {
+                throw new \LogicException(sprintf('The "@=" expression syntax cannot be used without the ExpressionLanguage component. Try running "composer require symfony/expression-language".'));
+            }
+
             return new Expression(substr($value, 2));
         } elseif (is_string($value) && 0 === strpos($value, '@')) {
             if (0 === strpos($value, '@@')) {
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
index 250965b898e83..906341034f726 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
@@ -685,6 +685,24 @@ public function provideNotWireableCalls()
         );
     }
 
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\AutowiringFailedException
+     * @expectedExceptionMessage Cannot autowire service "foo": argument "$sam" of method "Symfony\Component\DependencyInjection\Tests\Compiler\NotWireable::setNotAutowireableBecauseOfATypo()" references class "Symfony\Component\DependencyInjection\Tests\Compiler\lesTilleuls" but no such service exists. Did you mean "Symfony\Component\DependencyInjection\Tests\Compiler\LesTilleuls"?
+     */
+    public function testSuggestRegisteredServicesWithSimilarCase()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register(LesTilleuls::class, LesTilleuls::class);
+        $container->register('foo', NotWireable::class)->setAutowired(true)
+            ->addMethodCall('setNotAutowireableBecauseOfATypo', array())
+        ;
+
+        (new ResolveClassPass())->process($container);
+        (new AutowireRequiredMethodsPass())->process($container);
+        (new AutowirePass())->process($container);
+    }
+
     /**
      * @expectedException \Symfony\Component\DependencyInjection\Exception\AutowiringFailedException
      * @expectedExceptionMessage Cannot autowire service "j": argument "$i" of method "Symfony\Component\DependencyInjection\Tests\Compiler\J::__construct()" references class "Symfony\Component\DependencyInjection\Tests\Compiler\I" but no such service exists. Try changing the type-hint to "Symfony\Component\DependencyInjection\Tests\Compiler\IInterface" instead.
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/InlineServiceDefinitionsPassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/InlineServiceDefinitionsPassTest.php
index 3e1cf8a8c2b10..9630cca14f015 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/InlineServiceDefinitionsPassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/InlineServiceDefinitionsPassTest.php
@@ -92,6 +92,25 @@ public function testProcessDoesInlineNonSharedService()
         $this->assertNotSame($container->getDefinition('bar'), $arguments[2]);
     }
 
+    public function testProcessInlinesMixedServicesLoop()
+    {
+        $container = new ContainerBuilder();
+        $container
+            ->register('foo')
+            ->addArgument(new Reference('bar'))
+            ->setShared(false)
+        ;
+        $container
+            ->register('bar')
+            ->setPublic(false)
+            ->addMethodCall('setFoo', array(new Reference('foo')))
+        ;
+
+        $this->process($container);
+
+        $this->assertEquals($container->getDefinition('foo')->getArgument(0), $container->getDefinition('bar'));
+    }
+
     public function testProcessInlinesIfMultipleReferencesButAllFromTheSameDefinition()
     {
         $container = new ContainerBuilder();
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/MergeExtensionConfigurationPassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/MergeExtensionConfigurationPassTest.php
index b64aa7778cbe8..fccda7e129847 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/MergeExtensionConfigurationPassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/MergeExtensionConfigurationPassTest.php
@@ -110,10 +110,26 @@ public function testProcessedEnvsAreIncompatibleWithResolve()
     {
         $container = new ContainerBuilder();
         $container->registerExtension(new BarExtension());
-        $container->prependExtensionConfig('bar', array());
+        $container->prependExtensionConfig('bar', []);
 
         (new MergeExtensionConfigurationPass())->process($container);
     }
+
+    public function testThrowingExtensionsGetMergedBag()
+    {
+        $container = new ContainerBuilder();
+        $container->registerExtension(new ThrowingExtension());
+        $container->prependExtensionConfig('throwing', array('bar' => '%env(FOO)%'));
+
+        try {
+            $pass = new MergeExtensionConfigurationPass();
+            $pass->process($container);
+            $this->fail('An exception should have been thrown.');
+        } catch (\Exception $e) {
+        }
+
+        $this->assertSame(array('FOO'), array_keys($container->getParameterBag()->getEnvPlaceholders()));
+    }
 }
 
 class FooConfiguration implements ConfigurationInterface
@@ -163,3 +179,21 @@ public function load(array $configs, ContainerBuilder $container)
         $container->resolveEnvPlaceholders('%env(int:FOO)%', true);
     }
 }
+
+class ThrowingExtension extends Extension
+{
+    public function getAlias()
+    {
+        return 'throwing';
+    }
+
+    public function getConfiguration(array $config, ContainerBuilder $container)
+    {
+        return new FooConfiguration();
+    }
+
+    public function load(array $configs, ContainerBuilder $container)
+    {
+        throw new \Exception();
+    }
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/ContainerBuilderTest.php b/src/Symfony/Component/DependencyInjection/Tests/ContainerBuilderTest.php
index 5bcb915bc139c..1a52ebf5f9b22 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/ContainerBuilderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/ContainerBuilderTest.php
@@ -1223,24 +1223,26 @@ public function testUninitializedReference()
         $this->assertEquals(array('foo1' => new \stdClass(), 'foo3' => new \stdClass()), iterator_to_array($bar->iter));
     }
 
-    public function testAlmostCircularPrivate()
+    /**
+     * @dataProvider provideAlmostCircular
+     */
+    public function testAlmostCircular($visibility)
     {
-        $public = false;
         $container = include __DIR__.'/Fixtures/containers/container_almost_circular.php';
 
         $foo = $container->get('foo');
-
         $this->assertSame($foo, $foo->bar->foobar->foo);
-    }
 
-    public function testAlmostCircularPublic()
-    {
-        $public = true;
-        $container = include __DIR__.'/Fixtures/containers/container_almost_circular.php';
+        $foo2 = $container->get('foo2');
+        $this->assertSame($foo2, $foo2->bar->foobar->foo);
 
-        $foo = $container->get('foo');
+        $this->assertSame(array(), (array) $container->get('foobar4'));
+    }
 
-        $this->assertSame($foo, $foo->bar->foobar->foo);
+    public function provideAlmostCircular()
+    {
+        yield array('public');
+        yield array('private');
     }
 
     public function testRegisterForAutoconfiguration()
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php b/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php
index e1a5a28f159fd..8dadbb8fbfd01 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php
@@ -301,21 +301,6 @@ public function testOverrideServiceWhenUsingADumpedContainer()
         $this->assertSame($decorator, $container->get('decorator_service'), '->set() overrides an already defined service');
     }
 
-    /**
-     * @expectedException \Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException
-     */
-    public function testCircularReference()
-    {
-        $container = new ContainerBuilder();
-        $container->register('foo', 'stdClass')->addArgument(new Reference('bar'))->setPublic(true);
-        $container->register('bar', 'stdClass')->setPublic(false)->addMethodCall('setA', array(new Reference('baz')));
-        $container->register('baz', 'stdClass')->addMethodCall('setA', array(new Reference('foo')))->setPublic(true);
-        $container->compile();
-
-        $dumper = new PhpDumper($container);
-        $dumper->dump();
-    }
-
     public function testDumpAutowireData()
     {
         $container = include self::$fixturesPath.'/containers/container24.php';
@@ -773,38 +758,35 @@ public function testUninitializedReference()
         $this->assertEquals(array('foo1' => new \stdClass(), 'foo3' => new \stdClass()), iterator_to_array($bar->iter));
     }
 
-    public function testAlmostCircularPrivate()
+    /**
+     * @dataProvider provideAlmostCircular
+     */
+    public function testAlmostCircular($visibility)
     {
-        $public = false;
         $container = include self::$fixturesPath.'/containers/container_almost_circular.php';
         $container->compile();
         $dumper = new PhpDumper($container);
 
-        $this->assertStringEqualsFile(self::$fixturesPath.'/php/container_almost_circular_private.php', $dumper->dump(array('class' => 'Symfony_DI_PhpDumper_Test_Almost_Circular_Private')));
+        $container = 'Symfony_DI_PhpDumper_Test_Almost_Circular_'.ucfirst($visibility);
+        $this->assertStringEqualsFile(self::$fixturesPath.'/php/services_almost_circular_'.$visibility.'.php', $dumper->dump(array('class' => $container)));
 
-        require self::$fixturesPath.'/php/container_almost_circular_private.php';
+        require self::$fixturesPath.'/php/services_almost_circular_'.$visibility.'.php';
 
-        $container = new \Symfony_DI_PhpDumper_Test_Almost_Circular_Private();
-        $foo = $container->get('foo');
+        $container = new $container();
 
+        $foo = $container->get('foo');
         $this->assertSame($foo, $foo->bar->foobar->foo);
-    }
 
-    public function testAlmostCircularPublic()
-    {
-        $public = true;
-        $container = include self::$fixturesPath.'/containers/container_almost_circular.php';
-        $container->compile();
-        $dumper = new PhpDumper($container);
+        $foo2 = $container->get('foo2');
+        $this->assertSame($foo2, $foo2->bar->foobar->foo);
 
-        $this->assertStringEqualsFile(self::$fixturesPath.'/php/container_almost_circular_public.php', $dumper->dump(array('class' => 'Symfony_DI_PhpDumper_Test_Almost_Circular_Public')));
-
-        require self::$fixturesPath.'/php/container_almost_circular_public.php';
-
-        $container = new \Symfony_DI_PhpDumper_Test_Almost_Circular_Public();
-        $foo = $container->get('foo');
+        $this->assertSame(array(), (array) $container->get('foobar4'));
+    }
 
-        $this->assertSame($foo, $foo->bar->foobar->foo);
+    public function provideAlmostCircular()
+    {
+        yield array('public');
+        yield array('private');
     }
 
     public function testHotPathOptimizations()
@@ -814,12 +796,12 @@ public function testHotPathOptimizations()
         $container->compile();
         $dumper = new PhpDumper($container);
 
-        $dump = $dumper->dump(array('hot_path_tag' => 'container.hot_path', 'inline_class_loader_parameter' => 'inline_requires', 'file' => self::$fixturesPath.'/php/container_inline_requires.php'));
+        $dump = $dumper->dump(array('hot_path_tag' => 'container.hot_path', 'inline_class_loader_parameter' => 'inline_requires', 'file' => self::$fixturesPath.'/php/services_inline_requires.php'));
         if ('\\' === DIRECTORY_SEPARATOR) {
             $dump = str_replace("'\\\\includes\\\\HotPath\\\\", "'/includes/HotPath/", $dump);
         }
 
-        $this->assertStringEqualsFile(self::$fixturesPath.'/php/container_inline_requires.php', $dump);
+        $this->assertStringEqualsFile(self::$fixturesPath.'/php/services_inline_requires.php', $dump);
     }
 
     public function testDumpHandlesLiteralClassWithRootNamespace()
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/ParentNotExists.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/ParentNotExists.php
new file mode 100644
index 0000000000000..ae637f917fef0
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/ParentNotExists.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures;
+
+class ParentNotExists extends \NotExists
+{
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_almost_circular.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_almost_circular.php
index eaef674a3ec5b..6d73b3ec6c774 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_almost_circular.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_almost_circular.php
@@ -5,8 +5,11 @@
 use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
 use Symfony\Component\DependencyInjection\Reference;
 
+$public = 'public' === $visibility;
 $container = new ContainerBuilder();
 
+// same visibility for deps
+
 $container->register('foo', FooCircular::class)->setPublic(true)
    ->addArgument(new Reference('bar'));
 
@@ -16,4 +19,31 @@
 $container->register('foobar', FoobarCircular::class)->setPublic($public)
     ->addArgument(new Reference('foo'));
 
+// mixed visibility for deps
+
+$container->register('foo2', FooCircular::class)->setPublic(true)
+   ->addArgument(new Reference('bar2'));
+
+$container->register('bar2', BarCircular::class)->setPublic(!$public)
+    ->addMethodCall('addFoobar', array(new Reference('foobar2')));
+
+$container->register('foobar2', FoobarCircular::class)->setPublic($public)
+    ->addArgument(new Reference('foo2'));
+
+// simple inline setter with internal reference
+
+$container->register('bar3', BarCircular::class)->setPublic(true)
+    ->addMethodCall('addFoobar', array(new Reference('foobar3'), new Reference('foobar3')));
+
+$container->register('foobar3', FoobarCircular::class)->setPublic($public);
+
+// loop with non-shared dep
+
+$container->register('foo4', 'stdClass')->setPublic($public)
+    ->setShared(false)
+    ->setProperty('foobar', new Reference('foobar4'));
+
+$container->register('foobar4', 'stdClass')->setPublic(true)
+    ->addArgument(new Reference('foo4'));
+
 return $container;
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_inline_requires.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_inline_requires.php
index 1acbfdfcaf81e..3bbfa31fa3c46 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_inline_requires.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_inline_requires.php
@@ -7,11 +7,13 @@
 use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\includes\HotPath;
+use Symfony\Component\DependencyInjection\Tests\Fixtures\ParentNotExists;
 
 $container = new ContainerBuilder();
 
 $container->register(HotPath\C1::class)->addTag('container.hot_path')->setPublic(true);
 $container->register(HotPath\C2::class)->addArgument(new Reference(HotPath\C3::class))->setPublic(true);
 $container->register(HotPath\C3::class);
+$container->register(ParentNotExists::class)->setPublic(true);
 
 return $container;
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/autowiring_classes.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/autowiring_classes.php
index bf99eff6a2838..ae1e92eadbafd 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/autowiring_classes.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/autowiring_classes.php
@@ -299,6 +299,10 @@ public function setNotAutowireable(NotARealClass $n)
     {
     }
 
+    public function setNotAutowireableBecauseOfATypo(lesTilleuls $sam)
+    {
+    }
+
     public function setBar()
     {
     }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt
index 7d70b4288d001..579bf285ad643 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt
@@ -66,11 +66,11 @@ use Symfony\Component\DependencyInjection\Argument\RewindableGenerator;
 // This file has been auto-generated by the Symfony Dependency Injection Component for internal use.
 // Returns the public 'configured_service' shared service.
 
+$this->services['configured_service'] = $instance = new \stdClass();
+
 $a = new \ConfClass();
 $a->setFoo(($this->services['baz'] ?? $this->load(__DIR__.'/getBazService.php')));
 
-$this->services['configured_service'] = $instance = new \stdClass();
-
 $a->configureStdClass($instance);
 
 return $instance;
@@ -186,10 +186,10 @@ use Symfony\Component\DependencyInjection\Argument\RewindableGenerator;
 // This file has been auto-generated by the Symfony Dependency Injection Component for internal use.
 // Returns the public 'foo_with_inline' shared service.
 
-$a = new \Bar();
-
 $this->services['foo_with_inline'] = $instance = new \Foo();
 
+$a = new \Bar();
+
 $a->pub = 'pub';
 $a->setBaz(($this->services['baz'] ?? $this->load(__DIR__.'/getBazService.php')));
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
index 47ccfc5e4d2ad..72e06b3416f69 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
@@ -162,11 +162,11 @@ protected function getBazService()
      */
     protected function getConfiguredServiceService()
     {
+        $this->services['configured_service'] = $instance = new \stdClass();
+
         $a = new \ConfClass();
         $a->setFoo(($this->services['baz'] ?? $this->getBazService()));
 
-        $this->services['configured_service'] = $instance = new \stdClass();
-
         $a->configureStdClass($instance);
 
         return $instance;
@@ -292,10 +292,10 @@ protected function getFooBarService()
      */
     protected function getFooWithInlineService()
     {
-        $a = new \Bar();
-
         $this->services['foo_with_inline'] = $instance = new \Foo();
 
+        $a = new \Bar();
+
         $a->pub = 'pub';
         $a->setBaz(($this->services['baz'] ?? $this->getBazService()));
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_almost_circular_private.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_private.php
similarity index 54%
rename from src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_almost_circular_private.php
rename to src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_private.php
index 3a3f753c1fd3f..76af8a5484861 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_almost_circular_private.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_private.php
@@ -24,7 +24,11 @@ public function __construct()
     {
         $this->services = $this->privates = array();
         $this->methodMap = array(
+            'bar2' => 'getBar2Service',
+            'bar3' => 'getBar3Service',
             'foo' => 'getFooService',
+            'foo2' => 'getFoo2Service',
+            'foobar4' => 'getFoobar4Service',
         );
 
         $this->aliases = array();
@@ -52,10 +56,43 @@ public function getRemovedIds()
             'Psr\\Container\\ContainerInterface' => true,
             'Symfony\\Component\\DependencyInjection\\ContainerInterface' => true,
             'bar' => true,
+            'foo4' => true,
             'foobar' => true,
+            'foobar2' => true,
+            'foobar3' => true,
         );
     }
 
+    /**
+     * Gets the public 'bar2' shared service.
+     *
+     * @return \BarCircular
+     */
+    protected function getBar2Service()
+    {
+        $this->services['bar2'] = $instance = new \BarCircular();
+
+        $instance->addFoobar(new \FoobarCircular(($this->services['foo2'] ?? $this->getFoo2Service())));
+
+        return $instance;
+    }
+
+    /**
+     * Gets the public 'bar3' shared service.
+     *
+     * @return \BarCircular
+     */
+    protected function getBar3Service()
+    {
+        $this->services['bar3'] = $instance = new \BarCircular();
+
+        $a = new \FoobarCircular();
+
+        $instance->addFoobar($a, $a);
+
+        return $instance;
+    }
+
     /**
      * Gets the public 'foo' shared service.
      *
@@ -69,6 +106,37 @@ protected function getFooService()
 
         $a->addFoobar(new \FoobarCircular($instance));
 
+        return $instance;
+    }
+
+    /**
+     * Gets the public 'foo2' shared service.
+     *
+     * @return \FooCircular
+     */
+    protected function getFoo2Service()
+    {
+        $a = ($this->services['bar2'] ?? $this->getBar2Service());
+
+        if (isset($this->services['foo2'])) {
+            return $this->services['foo2'];
+        }
+
+        return $this->services['foo2'] = new \FooCircular($a);
+    }
+
+    /**
+     * Gets the public 'foobar4' shared service.
+     *
+     * @return \stdClass
+     */
+    protected function getFoobar4Service()
+    {
+        $a = new \stdClass();
+
+        $this->services['foobar4'] = $instance = new \stdClass($a);
+
+        $a->foobar = $instance;
 
         return $instance;
     }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_almost_circular_public.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_public.php
similarity index 54%
rename from src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_almost_circular_public.php
rename to src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_public.php
index a306443e88109..a552a22b43358 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_almost_circular_public.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_public.php
@@ -25,8 +25,14 @@ public function __construct()
         $this->services = $this->privates = array();
         $this->methodMap = array(
             'bar' => 'getBarService',
+            'bar3' => 'getBar3Service',
             'foo' => 'getFooService',
+            'foo2' => 'getFoo2Service',
+            'foo4' => 'getFoo4Service',
             'foobar' => 'getFoobarService',
+            'foobar2' => 'getFoobar2Service',
+            'foobar3' => 'getFoobar3Service',
+            'foobar4' => 'getFoobar4Service',
         );
 
         $this->aliases = array();
@@ -53,6 +59,7 @@ public function getRemovedIds()
         return array(
             'Psr\\Container\\ContainerInterface' => true,
             'Symfony\\Component\\DependencyInjection\\ContainerInterface' => true,
+            'bar2' => true,
         );
     }
 
@@ -70,6 +77,22 @@ protected function getBarService()
         return $instance;
     }
 
+    /**
+     * Gets the public 'bar3' shared service.
+     *
+     * @return \BarCircular
+     */
+    protected function getBar3Service()
+    {
+        $this->services['bar3'] = $instance = new \BarCircular();
+
+        $a = ($this->services['foobar3'] ?? $this->services['foobar3'] = new \FoobarCircular());
+
+        $instance->addFoobar($a, $a);
+
+        return $instance;
+    }
+
     /**
      * Gets the public 'foo' shared service.
      *
@@ -86,6 +109,36 @@ protected function getFooService()
         return $this->services['foo'] = new \FooCircular($a);
     }
 
+    /**
+     * Gets the public 'foo2' shared service.
+     *
+     * @return \FooCircular
+     */
+    protected function getFoo2Service()
+    {
+        $a = new \BarCircular();
+
+        $this->services['foo2'] = $instance = new \FooCircular($a);
+
+        $a->addFoobar(($this->services['foobar2'] ?? $this->getFoobar2Service()));
+
+        return $instance;
+    }
+
+    /**
+     * Gets the public 'foo4' service.
+     *
+     * @return \stdClass
+     */
+    protected function getFoo4Service()
+    {
+        $instance = new \stdClass();
+
+        $instance->foobar = ($this->services['foobar4'] ?? $this->getFoobar4Service());
+
+        return $instance;
+    }
+
     /**
      * Gets the public 'foobar' shared service.
      *
@@ -101,4 +154,46 @@ protected function getFoobarService()
 
         return $this->services['foobar'] = new \FoobarCircular($a);
     }
+
+    /**
+     * Gets the public 'foobar2' shared service.
+     *
+     * @return \FoobarCircular
+     */
+    protected function getFoobar2Service()
+    {
+        $a = ($this->services['foo2'] ?? $this->getFoo2Service());
+
+        if (isset($this->services['foobar2'])) {
+            return $this->services['foobar2'];
+        }
+
+        return $this->services['foobar2'] = new \FoobarCircular($a);
+    }
+
+    /**
+     * Gets the public 'foobar3' shared service.
+     *
+     * @return \FoobarCircular
+     */
+    protected function getFoobar3Service()
+    {
+        return $this->services['foobar3'] = new \FoobarCircular();
+    }
+
+    /**
+     * Gets the public 'foobar4' shared service.
+     *
+     * @return \stdClass
+     */
+    protected function getFoobar4Service()
+    {
+        $a = new \stdClass();
+
+        $this->services['foobar4'] = $instance = new \stdClass($a);
+
+        $a->foobar = $instance;
+
+        return $instance;
+    }
 }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_inline_requires.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_requires.php
similarity index 90%
rename from src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_inline_requires.php
rename to src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_requires.php
index 19bc72a43e6ee..05bae361195d4 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_inline_requires.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_requires.php
@@ -30,6 +30,7 @@ public function __construct()
 
         $this->services = $this->privates = array();
         $this->methodMap = array(
+            'Symfony\\Component\\DependencyInjection\\Tests\\Fixtures\\ParentNotExists' => 'getParentNotExistsService',
             'Symfony\\Component\\DependencyInjection\\Tests\\Fixtures\\includes\\HotPath\\C1' => 'getC1Service',
             'Symfony\\Component\\DependencyInjection\\Tests\\Fixtures\\includes\\HotPath\\C2' => 'getC2Service',
         );
@@ -67,6 +68,16 @@ public function getRemovedIds()
         );
     }
 
+    /**
+     * Gets the public 'Symfony\Component\DependencyInjection\Tests\Fixtures\ParentNotExists' shared service.
+     *
+     * @return \Symfony\Component\DependencyInjection\Tests\Fixtures\ParentNotExists
+     */
+    protected function getParentNotExistsService()
+    {
+        return $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\ParentNotExists'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\ParentNotExists();
+    }
+
     /**
      * Gets the public 'Symfony\Component\DependencyInjection\Tests\Fixtures\includes\HotPath\C1' shared service.
      *
@@ -84,8 +95,8 @@ protected function getC1Service()
      */
     protected function getC2Service()
     {
-        require_once $this->targetDirs[1].'/includes/HotPath/C2.php';
         require_once $this->targetDirs[1].'/includes/HotPath/C3.php';
+        require_once $this->targetDirs[1].'/includes/HotPath/C2.php';
 
         return $this->services['Symfony\Component\DependencyInjection\Tests\Fixtures\includes\HotPath\C2'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\includes\HotPath\C2(new \Symfony\Component\DependencyInjection\Tests\Fixtures\includes\HotPath\C3());
     }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php
index f4b6ea500cf49..b8aba31b1ea8b 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php
@@ -156,12 +156,12 @@ protected function getTranslator2Service()
      */
     protected function getTranslator3Service()
     {
-        $a = ($this->services['translator.loader_3'] ?? $this->services['translator.loader_3'] = new \stdClass());
-
         $this->services['translator_3'] = $instance = new \Symfony\Component\DependencyInjection\Tests\Fixtures\StubbedTranslator(new \Symfony\Component\DependencyInjection\ServiceLocator(array('translator.loader_3' => function () {
             return ($this->services['translator.loader_3'] ?? $this->services['translator.loader_3'] = new \stdClass());
         })));
 
+        $a = ($this->services['translator.loader_3'] ?? $this->services['translator.loader_3'] = new \stdClass());
+
         $instance->addResource('db', $a, 'nl');
         $instance->addResource('db', $a, 'en');
 
diff --git a/src/Symfony/Component/Dotenv/Dotenv.php b/src/Symfony/Component/Dotenv/Dotenv.php
index c5f28d6e697fc..dc9aa11123e2e 100644
--- a/src/Symfony/Component/Dotenv/Dotenv.php
+++ b/src/Symfony/Component/Dotenv/Dotenv.php
@@ -174,7 +174,7 @@ private function lexVarname()
 
     private function lexValue()
     {
-        if (preg_match('/[ \t]*+(?:#.*)?$/Am', $this->data, $matches, null, $this->cursor)) {
+        if (preg_match('/[ \t]*+(?:#.*)?$/Am', $this->data, $matches, 0, $this->cursor)) {
             $this->moveCursor($matches[0]);
             $this->skipEmptyLines();
 
@@ -296,7 +296,7 @@ private function lexNestedExpression()
 
     private function skipEmptyLines()
     {
-        if (preg_match('/(?:\s*+(?:#[^\n]*+)?+)++/A', $this->data, $match, null, $this->cursor)) {
+        if (preg_match('/(?:\s*+(?:#[^\n]*+)?+)++/A', $this->data, $match, 0, $this->cursor)) {
             $this->moveCursor($match[0]);
         }
     }
diff --git a/src/Symfony/Component/Form/Extension/Core/Type/FileType.php b/src/Symfony/Component/Form/Extension/Core/Type/FileType.php
index b67736b0ec8ed..387325782933c 100644
--- a/src/Symfony/Component/Form/Extension/Core/Type/FileType.php
+++ b/src/Symfony/Component/Form/Extension/Core/Type/FileType.php
@@ -92,9 +92,12 @@ public function finishView(FormView $view, FormInterface $form, array $options)
      */
     public function configureOptions(OptionsResolver $resolver)
     {
-        $dataClass = function (Options $options) {
-            return $options['multiple'] ? null : 'Symfony\Component\HttpFoundation\File\File';
-        };
+        $dataClass = null;
+        if (class_exists('Symfony\Component\HttpFoundation\File\File')) {
+            $dataClass = function (Options $options) {
+                return $options['multiple'] ? null : 'Symfony\Component\HttpFoundation\File\File';
+            };
+        }
 
         $emptyData = function (Options $options) {
             return $options['multiple'] ? array() : null;
diff --git a/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php b/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php
index 08784fcda19d4..ef23457b410f4 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Flash/AutoExpireFlashBag.php
@@ -106,7 +106,7 @@ public function get($type, array $default = array())
     public function all()
     {
         $return = $this->flashes['display'];
-        $this->flashes = array('new' => array(), 'display' => array());
+        $this->flashes['display'] = array();
 
         return $return;
     }
diff --git a/src/Symfony/Component/HttpFoundation/Session/Session.php b/src/Symfony/Component/HttpFoundation/Session/Session.php
index 09caa3442fa49..0c3371fab6c6d 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Session.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Session.php
@@ -28,6 +28,7 @@ class Session implements SessionInterface, \IteratorAggregate, \Countable
 
     private $flashName;
     private $attributeName;
+    private $data = array();
 
     /**
      * @param SessionStorageInterface $storage    A SessionStorageInterface instance
@@ -108,7 +109,7 @@ public function remove($name)
      */
     public function clear()
     {
-        $this->storage->getBag($this->attributeName)->clear();
+        $this->getAttributeBag()->clear();
     }
 
     /**
@@ -139,6 +140,22 @@ public function count()
         return count($this->getAttributeBag()->all());
     }
 
+    /**
+     * @return bool
+     *
+     * @internal
+     */
+    public function isEmpty()
+    {
+        foreach ($this->data as &$data) {
+            if (!empty($data)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -210,7 +227,7 @@ public function getMetadataBag()
      */
     public function registerBag(SessionBagInterface $bag)
     {
-        $this->storage->registerBag($bag);
+        $this->storage->registerBag(new SessionBagProxy($bag, $this->data));
     }
 
     /**
@@ -218,7 +235,7 @@ public function registerBag(SessionBagInterface $bag)
      */
     public function getBag($name)
     {
-        return $this->storage->getBag($name);
+        return $this->storage->getBag($name)->getBag();
     }
 
     /**
@@ -240,6 +257,6 @@ public function getFlashBag()
      */
     private function getAttributeBag()
     {
-        return $this->storage->getBag($this->attributeName);
+        return $this->storage->getBag($this->attributeName)->getBag();
     }
 }
diff --git a/src/Symfony/Component/HttpFoundation/Session/SessionBagProxy.php b/src/Symfony/Component/HttpFoundation/Session/SessionBagProxy.php
new file mode 100644
index 0000000000000..6c4cab6716456
--- /dev/null
+++ b/src/Symfony/Component/HttpFoundation/Session/SessionBagProxy.php
@@ -0,0 +1,79 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpFoundation\Session;
+
+/**
+ * @author Nicolas Grekas <p@tchwork.com>
+ *
+ * @internal
+ */
+final class SessionBagProxy implements SessionBagInterface
+{
+    private $bag;
+    private $data;
+
+    public function __construct(SessionBagInterface $bag, array &$data)
+    {
+        $this->bag = $bag;
+        $this->data = &$data;
+    }
+
+    /**
+     * @return SessionBagInterface
+     */
+    public function getBag()
+    {
+        return $this->bag;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isEmpty()
+    {
+        return empty($this->data[$this->bag->getStorageKey()]);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getName()
+    {
+        return $this->bag->getName();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function initialize(array &$array)
+    {
+        $this->data[$this->bag->getStorageKey()] = &$array;
+
+        $this->bag->initialize($array);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getStorageKey()
+    {
+        return $this->bag->getStorageKey();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function clear()
+    {
+        return $this->bag->clear();
+    }
+}
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php b/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php
index 23a05492166fa..732f92abf9e4d 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php
@@ -91,7 +91,26 @@ public function save()
             throw new \RuntimeException('Trying to save a session that was not started yet or was already closed');
         }
 
-        file_put_contents($this->getFilePath(), serialize($this->data));
+        $data = $this->data;
+
+        foreach ($this->bags as $bag) {
+            if (empty($data[$key = $bag->getStorageKey()])) {
+                unset($data[$key]);
+            }
+        }
+        if (array($key = $this->metadataBag->getStorageKey()) === array_keys($data)) {
+            unset($data[$key]);
+        }
+
+        try {
+            if ($data) {
+                file_put_contents($this->getFilePath(), serialize($data));
+            } else {
+                $this->destroy();
+            }
+        } finally {
+            $this->data = $data;
+        }
 
         // this is needed for Silex, where the session object is re-used across requests
         // in functional tests. In Symfony, the container is rebooted, so we don't have
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Session/Flash/AutoExpireFlashBagTest.php b/src/Symfony/Component/HttpFoundation/Tests/Session/Flash/AutoExpireFlashBagTest.php
index a4d176a100d9e..fa8626ab923b7 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Session/Flash/AutoExpireFlashBagTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Session/Flash/AutoExpireFlashBagTest.php
@@ -150,4 +150,12 @@ public function testClear()
     {
         $this->assertEquals(array('notice' => array('A previous flash message')), $this->bag->clear());
     }
+
+    public function testDoNotRemoveTheNewFlashesWhenDisplayingTheExistingOnes()
+    {
+        $this->bag->add('success', 'Something');
+        $this->bag->all();
+
+        $this->assertEquals(array('new' => array('success' => array('Something')), 'display' => array()), $this->array);
+    }
 }
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php b/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php
index fa93507a41aaf..41720e4b6fc4e 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php
@@ -221,4 +221,22 @@ public function testGetMeta()
     {
         $this->assertInstanceOf('Symfony\Component\HttpFoundation\Session\Storage\MetadataBag', $this->session->getMetadataBag());
     }
+
+    public function testIsEmpty()
+    {
+        $this->assertTrue($this->session->isEmpty());
+
+        $this->session->set('hello', 'world');
+        $this->assertFalse($this->session->isEmpty());
+
+        $this->session->remove('hello');
+        $this->assertTrue($this->session->isEmpty());
+
+        $flash = $this->session->getFlashBag();
+        $flash->set('hello', 'world');
+        $this->assertFalse($this->session->isEmpty());
+
+        $flash->get('hello');
+        $this->assertTrue($this->session->isEmpty());
+    }
 }
diff --git a/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php b/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
index fbcecad25e18a..7b0aa4b5a226e 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
@@ -13,6 +13,7 @@
 
 use Psr\Container\ContainerInterface;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\DependencyInjection\Container;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
@@ -86,6 +87,15 @@ protected function instantiateController($class)
             return $this->container->get($class);
         }
 
-        return parent::instantiateController($class);
+        try {
+            return parent::instantiateController($class);
+        } catch (\ArgumentCountError $e) {
+        }
+
+        if ($this->container instanceof Container && in_array($class, $this->container->getRemovedIds(), true)) {
+            throw new \LogicException(sprintf('Controller "%s" cannot be fetched from the container because it is private. Did you forget to tag the service with "controller.service_arguments"?', $class), 0, $e);
+        }
+
+        throw $e;
     }
 }
diff --git a/src/Symfony/Component/HttpKernel/EventListener/AbstractTestSessionListener.php b/src/Symfony/Component/HttpKernel/EventListener/AbstractTestSessionListener.php
index eb0320f6b91e6..2531db66790d2 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/AbstractTestSessionListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/AbstractTestSessionListener.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\HttpKernel\EventListener;
 
 use Symfony\Component\HttpFoundation\Cookie;
+use Symfony\Component\HttpFoundation\Session\Session;
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
 use Symfony\Component\HttpKernel\KernelEvents;
 use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
@@ -60,8 +61,10 @@ public function onKernelResponse(FilterResponseEvent $event)
         $session = $event->getRequest()->getSession();
         if ($session && $session->isStarted()) {
             $session->save();
-            $params = session_get_cookie_params();
-            $event->getResponse()->headers->setCookie(new Cookie($session->getName(), $session->getId(), 0 === $params['lifetime'] ? 0 : time() + $params['lifetime'], $params['path'], $params['domain'], $params['secure'], $params['httponly']));
+            if (!$session instanceof Session || !\method_exists($session, 'isEmpty') || !$session->isEmpty()) {
+                $params = session_get_cookie_params();
+                $event->getResponse()->headers->setCookie(new Cookie($session->getName(), $session->getId(), 0 === $params['lifetime'] ? 0 : time() + $params['lifetime'], $params['path'], $params['domain'], $params['secure'], $params['httponly']));
+            }
         }
     }
 
diff --git a/src/Symfony/Component/HttpKernel/Fragment/AbstractSurrogateFragmentRenderer.php b/src/Symfony/Component/HttpKernel/Fragment/AbstractSurrogateFragmentRenderer.php
index 2489a639376e1..ba1f3687038aa 100644
--- a/src/Symfony/Component/HttpKernel/Fragment/AbstractSurrogateFragmentRenderer.php
+++ b/src/Symfony/Component/HttpKernel/Fragment/AbstractSurrogateFragmentRenderer.php
@@ -98,8 +98,8 @@ private function generateSignedFragmentUri($uri, Request $request): string
     private function containsNonScalars(array $values): bool
     {
         foreach ($values as $value) {
-            if (is_array($value) && $this->containsNonScalars($value)) {
-                return true;
+            if (is_array($value)) {
+                return $this->containsNonScalars($value);
             } elseif (!is_scalar($value) && null !== $value) {
                 return true;
             }
diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index b0cd20167fe81..2a6d8a4fd17e8 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -63,12 +63,12 @@ abstract class Kernel implements KernelInterface, RebootableInterface, Terminabl
     private $requestStackSize = 0;
     private $resetServices = false;
 
-    const VERSION = '4.0.0-RC2';
+    const VERSION = '4.0.0';
     const VERSION_ID = 40000;
     const MAJOR_VERSION = 4;
     const MINOR_VERSION = 0;
     const RELEASE_VERSION = 0;
-    const EXTRA_VERSION = 'RC2';
+    const EXTRA_VERSION = '';
 
     const END_OF_MAINTENANCE = '07/2018';
     const END_OF_LIFE = '01/2019';
@@ -112,7 +112,7 @@ public function boot()
 
             return;
         }
-        if ($this->debug && !isset($_SERVER['SHELL_VERBOSITY'])) {
+        if ($this->debug && !isset($_ENV['SHELL_VERBOSITY']) && !isset($_SERVER['SHELL_VERBOSITY'])) {
             putenv('SHELL_VERBOSITY=3');
             $_ENV['SHELL_VERBOSITY'] = 3;
             $_SERVER['SHELL_VERBOSITY'] = 3;
@@ -451,8 +451,11 @@ protected function initializeContainer()
         $class = $this->getContainerClass();
         $cacheDir = $this->warmupDir ?: $this->getCacheDir();
         $cache = new ConfigCache($cacheDir.'/'.$class.'.php', $this->debug);
-        $fresh = true;
-        if (!$cache->isFresh()) {
+        if ($fresh = $cache->isFresh()) {
+            $this->container = require $cache->getPath();
+            $fresh = \is_object($this->container);
+        }
+        if (!$fresh) {
             if ($this->debug) {
                 $collectedLogs = array();
                 $previousHandler = set_error_handler(function ($type, $message, $file, $line) use (&$collectedLogs, &$previousHandler) {
@@ -502,11 +505,9 @@ protected function initializeContainer()
             $oldContainer = file_exists($cache->getPath()) && is_object($oldContainer = @include $cache->getPath()) ? new \ReflectionClass($oldContainer) : false;
 
             $this->dumpContainer($cache, $container, $class, $this->getContainerBaseClass());
-
-            $fresh = false;
+            $this->container = require $cache->getPath();
         }
 
-        $this->container = require $cache->getPath();
         $this->container->set('kernel', $this);
 
         if ($fresh) {
@@ -514,7 +515,17 @@ protected function initializeContainer()
         }
 
         if ($oldContainer && get_class($this->container) !== $oldContainer->name) {
-            (new Filesystem())->remove(dirname($oldContainer->getFileName()));
+            // Because concurrent requests might still be using them,
+            // old container files are not removed immediately,
+            // but on a next dump of the container.
+            $oldContainerDir = dirname($oldContainer->getFileName());
+            foreach (glob(dirname($oldContainerDir).'/*.legacyContainer') as $legacyContainer) {
+                if ($oldContainerDir.'.legacyContainer' !== $legacyContainer && @unlink($legacyContainer)) {
+                    (new Filesystem())->remove(substr($legacyContainer, 0, -16));
+                }
+            }
+
+            touch($oldContainerDir.'.legacyContainer');
         }
 
         if ($this->container->has('cache_warmer')) {
diff --git a/src/Symfony/Component/HttpKernel/Log/Logger.php b/src/Symfony/Component/HttpKernel/Log/Logger.php
index e26767f55d5e8..bf6ab49232fac 100644
--- a/src/Symfony/Component/HttpKernel/Log/Logger.php
+++ b/src/Symfony/Component/HttpKernel/Log/Logger.php
@@ -42,8 +42,8 @@ public function __construct(string $minLevel = null, $output = 'php://stderr', c
         if (null === $minLevel) {
             $minLevel = LogLevel::WARNING;
 
-            if (isset($_SERVER['SHELL_VERBOSITY'])) {
-                switch ((int) $_SERVER['SHELL_VERBOSITY']) {
+            if (isset($_ENV['SHELL_VERBOSITY']) || isset($_SERVER['SHELL_VERBOSITY'])) {
+                switch ((int) (isset($_ENV['SHELL_VERBOSITY']) ? $_ENV['SHELL_VERBOSITY'] : $_SERVER['SHELL_VERBOSITY'])) {
                     case -1: $minLevel = LogLevel::ERROR; break;
                     case 1: $minLevel = LogLevel::NOTICE; break;
                     case 2: $minLevel = LogLevel::INFO; break;
diff --git a/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php b/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php
index b3deb03c9138a..b3fa081a63c88 100644
--- a/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php
@@ -13,6 +13,8 @@
 
 use Psr\Container\ContainerInterface;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\Debug\ErrorHandler;
+use Symfony\Component\DependencyInjection\Container;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Controller\ContainerControllerResolver;
 
@@ -106,6 +108,38 @@ public function testNonInstantiableController()
         $this->assertSame(array(NonInstantiableController::class, 'action'), $controller);
     }
 
+    /**
+     * @expectedException \LogicException
+     * @expectedExceptionMessage Controller "Symfony\Component\HttpKernel\Tests\Controller\ImpossibleConstructController" cannot be fetched from the container because it is private. Did you forget to tag the service with "controller.service_arguments"?
+     */
+    public function testNonConstructController()
+    {
+        $container = $this->getMockBuilder(Container::class)->getMock();
+        $container->expects($this->at(0))
+            ->method('has')
+            ->with(ImpossibleConstructController::class)
+            ->will($this->returnValue(true))
+        ;
+
+        $container->expects($this->at(1))
+            ->method('has')
+            ->with(ImpossibleConstructController::class)
+            ->will($this->returnValue(false))
+        ;
+
+        $container->expects($this->atLeastOnce())
+            ->method('getRemovedIds')
+            ->with()
+            ->will($this->returnValue(array(ImpossibleConstructController::class)))
+        ;
+
+        $resolver = $this->createControllerResolver(null, $container);
+        $request = Request::create('/');
+        $request->attributes->set('_controller', array(ImpossibleConstructController::class, 'action'));
+
+        $resolver->getController($request);
+    }
+
     public function testNonInstantiableControllerWithCorrespondingService()
     {
         $service = new \stdClass();
@@ -196,3 +230,14 @@ public static function action()
     {
     }
 }
+
+class ImpossibleConstructController
+{
+    public function __construct($toto, $controller)
+    {
+    }
+
+    public function action()
+    {
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Tests/Event/FilterControllerArgumentsEventTest.php b/src/Symfony/Component/HttpKernel/Tests/Event/FilterControllerArgumentsEventTest.php
new file mode 100644
index 0000000000000..9165d31f24a15
--- /dev/null
+++ b/src/Symfony/Component/HttpKernel/Tests/Event/FilterControllerArgumentsEventTest.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace Symfony\Component\HttpKernel\Tests\Event;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Event\FilterControllerArgumentsEvent;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpKernel\Tests\TestHttpKernel;
+
+class FilterControllerArgumentsEventTest extends TestCase
+{
+    public function testFilterControllerArgumentsEvent()
+    {
+        $filterController = new FilterControllerArgumentsEvent(new TestHttpKernel(), function () {}, array('test'), new Request(), 1);
+        $this->assertEquals($filterController->getArguments(), array('test'));
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Tests/EventListener/TestSessionListenerTest.php b/src/Symfony/Component/HttpKernel/Tests/EventListener/TestSessionListenerTest.php
index 124bd64d848f3..4452f48771b8b 100644
--- a/src/Symfony/Component/HttpKernel/Tests/EventListener/TestSessionListenerTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/EventListener/TestSessionListenerTest.php
@@ -73,6 +73,19 @@ public function testDoesNotDeleteCookieIfUsingSessionLifetime()
         $this->assertEquals(0, reset($cookies)->getExpiresTime());
     }
 
+    /**
+     * @requires function \Symfony\Component\HttpFoundation\Session\Session::isEmpty
+     */
+    public function testEmptySessionDoesNotSendCookie()
+    {
+        $this->sessionHasBeenStarted();
+        $this->sessionIsEmpty();
+
+        $response = $this->filterResponse(new Request(), HttpKernelInterface::MASTER_REQUEST);
+
+        $this->assertSame(array(), $response->headers->getCookies());
+    }
+
     public function testUnstartedSessionIsNotSave()
     {
         $this->sessionHasNotBeenStarted();
@@ -130,6 +143,13 @@ private function sessionHasNotBeenStarted()
             ->will($this->returnValue(false));
     }
 
+    private function sessionIsEmpty()
+    {
+        $this->session->expects($this->once())
+            ->method('isEmpty')
+            ->will($this->returnValue(true));
+    }
+
     private function getSession()
     {
         $mock = $this->getMockBuilder('Symfony\Component\HttpFoundation\Session\Session')
diff --git a/src/Symfony/Component/HttpKernel/Tests/Fragment/EsiFragmentRendererTest.php b/src/Symfony/Component/HttpKernel/Tests/Fragment/EsiFragmentRendererTest.php
index 6cefea6b02f3b..8a40dcd5bb892 100644
--- a/src/Symfony/Component/HttpKernel/Tests/Fragment/EsiFragmentRendererTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/Fragment/EsiFragmentRendererTest.php
@@ -26,6 +26,14 @@ public function testRenderFallbackToInlineStrategyIfEsiNotSupported()
         $strategy->render('/', Request::create('/'));
     }
 
+    public function testRenderFallbackWithScalar()
+    {
+        $strategy = new EsiFragmentRenderer(new Esi(), $this->getInlineStrategy(true), new UriSigner('foo'));
+        $request = Request::create('/');
+        $reference = new ControllerReference('main_controller', array('foo' => array(true)), array());
+        $strategy->render($reference, $request);
+    }
+
     public function testRender()
     {
         $strategy = new EsiFragmentRenderer(new Esi(), $this->getInlineStrategy());
diff --git a/src/Symfony/Component/HttpKernel/Tests/KernelTest.php b/src/Symfony/Component/HttpKernel/Tests/KernelTest.php
index b70a859fff2f8..955b1cf83ba57 100644
--- a/src/Symfony/Component/HttpKernel/Tests/KernelTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/KernelTest.php
@@ -520,7 +520,8 @@ public function testKernelReset()
         $kernel->boot();
 
         $this->assertTrue(get_class($kernel->getContainer()) !== $containerClass);
-        $this->assertFileNotExists($containerFile);
+        $this->assertFileExists($containerFile);
+        $this->assertFileExists(dirname($containerFile).'.legacyContainer');
     }
 
     public function testKernelPass()
diff --git a/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php b/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
index f547b4984ffd4..406a36d2325a1 100644
--- a/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
+++ b/src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php
@@ -129,6 +129,10 @@ protected function getAttributes($object, $format = null, array $context)
             return $allowedAttributes;
         }
 
+        if (isset($context['attributes'])) {
+            return $this->extractAttributes($object, $format, $context);
+        }
+
         if (isset($this->attributesCache[$class])) {
             return $this->attributesCache[$class];
         }
diff --git a/src/Symfony/Component/Serializer/Tests/Normalizer/ObjectNormalizerTest.php b/src/Symfony/Component/Serializer/Tests/Normalizer/ObjectNormalizerTest.php
index f10937bd9c3a2..0d4e880ec7f18 100644
--- a/src/Symfony/Component/Serializer/Tests/Normalizer/ObjectNormalizerTest.php
+++ b/src/Symfony/Component/Serializer/Tests/Normalizer/ObjectNormalizerTest.php
@@ -723,6 +723,37 @@ public function testAttributesContextDenormalizeConstructor()
             'inner' => array('foo' => 'foo', 'bar' => 'bar'),
         ), DummyWithConstructorObjectAndDefaultValue::class, null, $context));
     }
+
+    public function testNormalizeSameObjectWithDifferentAttributes()
+    {
+        $classMetadataFactory = new ClassMetadataFactory(new AnnotationLoader(new AnnotationReader()));
+        $this->normalizer = new ObjectNormalizer($classMetadataFactory);
+        $serializer = new Serializer(array($this->normalizer));
+        $this->normalizer->setSerializer($serializer);
+
+        $dummy = new ObjectOuter();
+        $dummy->foo = new ObjectInner();
+        $dummy->foo->foo = 'foo.foo';
+        $dummy->foo->bar = 'foo.bar';
+
+        $dummy->bar = new ObjectInner();
+        $dummy->bar->foo = 'bar.foo';
+        $dummy->bar->bar = 'bar.bar';
+
+        $this->assertEquals(array(
+            'foo' => array(
+                'bar' => 'foo.bar',
+            ),
+            'bar' => array(
+                'foo' => 'bar.foo',
+            ),
+        ), $this->normalizer->normalize($dummy, 'json', array(
+            'attributes' => array(
+                'foo' => array('bar'),
+                'bar' => array('foo'),
+            ),
+        )));
+    }
 }
 
 class ObjectDummy
diff --git a/src/Symfony/Component/Translation/DependencyInjection/TranslatorPass.php b/src/Symfony/Component/Translation/DependencyInjection/TranslatorPass.php
index 7ec06684f5155..1f7839dbff35e 100644
--- a/src/Symfony/Component/Translation/DependencyInjection/TranslatorPass.php
+++ b/src/Symfony/Component/Translation/DependencyInjection/TranslatorPass.php
@@ -64,8 +64,15 @@ public function process(ContainerBuilder $container)
             ->replaceArgument(3, $loaders)
         ;
 
-        if ($container->hasParameter('twig.default_path')) {
+        if (!$container->hasParameter('twig.default_path')) {
+            return;
+        }
+
+        if ($container->hasDefinition($this->debugCommandServiceId)) {
             $container->getDefinition($this->debugCommandServiceId)->replaceArgument(4, $container->getParameter('twig.default_path'));
+        }
+
+        if ($container->hasDefinition($this->updateCommandServiceId)) {
             $container->getDefinition($this->updateCommandServiceId)->replaceArgument(5, $container->getParameter('twig.default_path'));
         }
     }
diff --git a/src/Symfony/Component/VarDumper/Caster/Caster.php b/src/Symfony/Component/VarDumper/Caster/Caster.php
index ee8dc3a3cd9c5..7f4e02283f580 100644
--- a/src/Symfony/Component/VarDumper/Caster/Caster.php
+++ b/src/Symfony/Component/VarDumper/Caster/Caster.php
@@ -113,8 +113,8 @@ public static function filter(array $a, $filter, array $listedProperties = array
 
             if (null === $v) {
                 $type |= self::EXCLUDE_NULL & $filter;
-            }
-            if (empty($v)) {
+                $type |= self::EXCLUDE_EMPTY & $filter;
+            } elseif (false === $v || '' === $v || '0' === $v || 0 === $v || 0.0 === $v || array() === $v) {
                 $type |= self::EXCLUDE_EMPTY & $filter;
             }
             if ((self::EXCLUDE_NOT_IMPORTANT & $filter) && !in_array($k, $listedProperties, true)) {
diff --git a/src/Symfony/Component/VarDumper/Cloner/VarCloner.php b/src/Symfony/Component/VarDumper/Cloner/VarCloner.php
index 79b920532f412..012743cd611da 100644
--- a/src/Symfony/Component/VarDumper/Cloner/VarCloner.php
+++ b/src/Symfony/Component/VarDumper/Cloner/VarCloner.php
@@ -101,13 +101,16 @@ protected function doClone($var)
                 // Create $stub when the original value $v can not be used directly
                 // If $v is a nested structure, put that structure in array $a
                 switch (true) {
-                    case empty($v):
-                    case true === $v:
+                    case null === $v:
+                    case \is_bool($v):
                     case \is_int($v):
                     case \is_float($v):
                         continue 2;
 
                     case \is_string($v):
+                        if ('' === $v) {
+                            continue 2;
+                        }
                         if (!\preg_match('//u', $v)) {
                             $stub = new Stub();
                             $stub->type = Stub::TYPE_STRING;
@@ -131,6 +134,9 @@ protected function doClone($var)
                         break;
 
                     case \is_array($v):
+                        if (!$v) {
+                            continue 2;
+                        }
                         $stub = $arrayStub;
                         $stub->class = Stub::ARRAY_INDEXED;
 
diff --git a/src/Symfony/Component/Yaml/Inline.php b/src/Symfony/Component/Yaml/Inline.php
index fe9f1d87e2ca7..475e46337ade2 100644
--- a/src/Symfony/Component/Yaml/Inline.php
+++ b/src/Symfony/Component/Yaml/Inline.php
@@ -402,6 +402,7 @@ private static function parseMapping(string $mapping, int $flags, int &$i = 0, a
         $output = array();
         $len = strlen($mapping);
         ++$i;
+        $allowOverwrite = false;
 
         // {foo: bar, bar:foo, ...}
         while ($i < $len) {
@@ -443,6 +444,10 @@ private static function parseMapping(string $mapping, int $flags, int &$i = 0, a
                 throw new ParseException('Colons must be followed by a space or an indication character (i.e. " ", ",", "[", "]", "{", "}").', self::$parsedLineNumber + 1, $mapping);
             }
 
+            if ('<<' === $key) {
+                $allowOverwrite = true;
+            }
+
             while ($i < $len) {
                 if (':' === $mapping[$i] || ' ' === $mapping[$i]) {
                     ++$i;
@@ -458,7 +463,18 @@ private static function parseMapping(string $mapping, int $flags, int &$i = 0, a
                         // Spec: Keys MUST be unique; first one wins.
                         // Parser cannot abort this mapping earlier, since lines
                         // are processed sequentially.
-                        if (isset($output[$key])) {
+                        // But overwriting is allowed when a merge node is used in current block.
+                        if ('<<' === $key) {
+                            foreach ($value as $parsedValue) {
+                                $output += $parsedValue;
+                            }
+                        } elseif ($allowOverwrite || !isset($output[$key])) {
+                            if (null !== $tag) {
+                                $output[$key] = new TaggedValue($tag, $value);
+                            } else {
+                                $output[$key] = $value;
+                            }
+                        } elseif (isset($output[$key])) {
                             throw new ParseException(sprintf('Duplicate key "%s" detected.', $key), self::$parsedLineNumber + 1, $mapping);
                         }
                         break;
@@ -468,7 +484,16 @@ private static function parseMapping(string $mapping, int $flags, int &$i = 0, a
                         // Spec: Keys MUST be unique; first one wins.
                         // Parser cannot abort this mapping earlier, since lines
                         // are processed sequentially.
-                        if (isset($output[$key])) {
+                        // But overwriting is allowed when a merge node is used in current block.
+                        if ('<<' === $key) {
+                            $output += $value;
+                        } elseif ($allowOverwrite || !isset($output[$key])) {
+                            if (null !== $tag) {
+                                $output[$key] = new TaggedValue($tag, $value);
+                            } else {
+                                $output[$key] = $value;
+                            }
+                        } elseif (isset($output[$key])) {
                             throw new ParseException(sprintf('Duplicate key "%s" detected.', $key), self::$parsedLineNumber + 1, $mapping);
                         }
                         break;
@@ -477,18 +502,20 @@ private static function parseMapping(string $mapping, int $flags, int &$i = 0, a
                         // Spec: Keys MUST be unique; first one wins.
                         // Parser cannot abort this mapping earlier, since lines
                         // are processed sequentially.
-                        if (isset($output[$key])) {
+                        // But overwriting is allowed when a merge node is used in current block.
+                        if ('<<' === $key) {
+                            $output += $value;
+                        } elseif ($allowOverwrite || !isset($output[$key])) {
+                            if (null !== $tag) {
+                                $output[$key] = new TaggedValue($tag, $value);
+                            } else {
+                                $output[$key] = $value;
+                            }
+                        } elseif (isset($output[$key])) {
                             throw new ParseException(sprintf('Duplicate key "%s" detected.', $key), self::$parsedLineNumber + 1, $mapping);
                         }
                         --$i;
                 }
-
-                if (null !== $tag && '' !== $tag) {
-                    $output[$key] = new TaggedValue($tag, $value);
-                } else {
-                    $output[$key] = $value;
-                }
-
                 ++$i;
 
                 continue 2;
diff --git a/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml b/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml
index 18e5abf939f7c..83264cfab8190 100644
--- a/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml
+++ b/src/Symfony/Component/Yaml/Tests/Fixtures/sfMergeKey.yml
@@ -21,6 +21,7 @@ yaml: |
         c:
             foo: bar
             bar: foo
+    bar_inline: {a: before, d: other, <<: *foo, b: new, x: Oren, c: { foo: bar, bar: foo}}
     foo2: &foo2
         a: Ballmer
     ding: &dong [ fi, fei, fo, fam]
@@ -42,14 +43,19 @@ yaml: |
             p: 12345
         z:
             <<: *nestedref
+    head_inline: &head_inline { <<: [ *foo , *dong , *foo2 ] }
+    recursive_inline: { <<: *head_inline, c: { <<: *foo2 } }
 php: |
     array(
         'foo' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'e' => 'notnull'),
         'bar' => array('a' => 'before', 'd' => 'other', 'e' => null, 'b' => 'new', 'c' => array('foo' => 'bar', 'bar' => 'foo'), 'x' => 'Oren'),
+        'bar_inline' => array('a' => 'before', 'd' => 'other', 'b' => 'new', 'c' => array('foo' => 'bar', 'bar' => 'foo'), 'e' => 'notnull', 'x' => 'Oren'),
         'foo2' => array('a' => 'Ballmer'),
         'ding' => array('fi', 'fei', 'fo', 'fam'),
         'check' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'e' => 'notnull', 'fi', 'fei', 'fo', 'fam', 'isit' => 'tested'),
         'head' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'e' => 'notnull', 'fi', 'fei', 'fo', 'fam'),
         'taz' => array('a' => 'Steve', 'w' => array('p' => 1234)),
-        'nested' => array('a' => 'Steve', 'w' => array('p' => 12345), 'd' => 'Doug', 'z' => array('p' => 12345))
+        'nested' => array('a' => 'Steve', 'w' => array('p' => 12345), 'd' => 'Doug', 'z' => array('p' => 12345)),
+        'head_inline' => array('a' => 'Steve', 'b' => 'Clark', 'c' => 'Brian', 'e' => 'notnull', 'fi', 'fei', 'fo', 'fam'),
+        'recursive_inline' => array('a' => 'Steve', 'b' => 'Clark', 'c' => array('a' => 'Ballmer'), 'e' => 'notnull', 'fi', 'fei', 'fo', 'fam'),
     )
diff --git a/src/Symfony/Component/Yaml/Tests/ParserTest.php b/src/Symfony/Component/Yaml/Tests/ParserTest.php
index fb28277abf040..b3b1465aaf379 100644
--- a/src/Symfony/Component/Yaml/Tests/ParserTest.php
+++ b/src/Symfony/Component/Yaml/Tests/ParserTest.php
@@ -1888,6 +1888,18 @@ public function testParseReferencesOnMergeKeysWithMappingsParsedAsObjects()
 
         $this->assertEquals($expected, $this->parser->parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
     }
+
+    /**
+     * @expectedException \Symfony\Component\Yaml\Exception\ParseException
+     * @expectedExceptionMessage Reference "foo" does not exist
+     */
+    public function testEvalRefException()
+    {
+        $yaml = <<<EOE
+foo: { &foo { a: Steve, <<: *foo} }
+EOE;
+        $this->parser->parse($yaml);
+    }
 }
 
 class B

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