Merge branch '3.4' into 4.0

* 3.4:
  [HttpFoundation] Use the correct syntax for session gc based on Pdo driver
  Removed assertDateTimeEquals() methods.
  Revert "bug #24987 [Console] Fix global console flag when used in chain (Simperfit)"
  Revert "bug #25487 [Console] Fix a bug when passing a letter that could be an alias (Simperfit)"
  Disable CSP header on exception pages only in debug
  Fixed submitting disabled buttons
  Fixed Button::setParent() when already submitted
  Improve assertions
  Restore RoleInterface import
  [Console] Provide a bugfix where an array could be passed
  Improve assertions
  SCA: get rid of repetitive calls
  allow null values for root nodes in YAML configs
  revert useless tests fixtures changes
  [VarDumper] Fix docblock
  Improve phpdoc to make it more explicit
  [DI] Fix initialization of legacy containers by delaying include_once

Author: fabpot

Container.php

@@ -142,6 +142,15 @@ public function setParameter($name, $value)
      */
     public function set($id, $service)
     {
+        // Runs the internal initializer; used by the dumped container to include always-needed files
+        if (isset($this->privates['service_container']) && $this->privates['service_container'] instanceof \Closure) {
+            $initialize = $this->privates['service_container'];
+            unset($this->privates['service_container']);
+            $initialize();
+        }
+
+        $id = $this->normalizeId($id);
+
         if ('service_container' === $id) {
             throw new InvalidArgumentException('You cannot set service "service_container".');
         }

ContainerBuilder.php

@@ -402,12 +402,16 @@ public function fileExists(string $path, $trackContents = true): bool
      * @throws BadMethodCallException When this ContainerBuilder is compiled
      * @throws \LogicException        if the extension is not registered
      */
-    public function loadFromExtension($extension, array $values = array())
+    public function loadFromExtension($extension, array $values = null)
     {
         if ($this->isCompiled()) {
             throw new BadMethodCallException('Cannot load from an extension on a compiled container.');
         }
 
+        if (func_num_args() < 2) {
+            $values = array();
+        }
+
         $namespace = $this->getExtension($extension)->getAlias();
 
         $this->extensionConfigs[$namespace][] = $values;

Dumper/PhpDumper.php

@@ -1096,16 +1096,16 @@ private function addInlineRequires(): string
             }
         }
 
-        $code = "\n";
+        $code = '';
 
         foreach ($lineage as $file) {
             if (!isset($this->inlinedRequires[$file])) {
                 $this->inlinedRequires[$file] = true;
-                $code .= sprintf("        include_once %s;\n", $file);
+                $code .= sprintf("\n            include_once %s;", $file);
             }
         }
 
-        return "\n" === $code ? '' : $code;
+        return $code ? sprintf("\n        \$this->privates['service_container'] = function () {%s\n        };\n", $code) : '';
     }
 
     private function addDefaultParametersMethod(): string

Loader/YamlFileLoader.php

@@ -768,7 +768,7 @@ private function loadFromExtensions(array $content)
                 continue;
             }
 
-            if (!is_array($values)) {
+            if (!is_array($values) && null !== $values) {
                 $values = array();
             }
 

Tests/Fixtures/includes/ProjectExtension.php

@@ -8,7 +8,14 @@ class ProjectExtension implements ExtensionInterface
 {
     public function load(array $configs, ContainerBuilder $configuration)
     {
-        $config = call_user_func_array('array_merge', $configs);
+        $configuration->setParameter('project.configs', $configs);
+        $configs = array_filter($configs);
+
+        if ($configs) {
+            $config = call_user_func_array('array_merge', $configs);
+        } else {
+            $config = array();
+        }
 
         $configuration->register('project.service.bar', 'FooClass')->setPublic(true);
         $configuration->setParameter('project.parameter.bar', isset($config['foo']) ? $config['foo'] : 'foobar');

Tests/Fixtures/php/services_inline_requires.php

@@ -41,10 +41,12 @@ public function __construct()
 
         $this->aliases = array();
 
-        include_once $this->targetDirs[1].'/includes/HotPath/I1.php';
-        include_once $this->targetDirs[1].'/includes/HotPath/P1.php';
-        include_once $this->targetDirs[1].'/includes/HotPath/T1.php';
-        include_once $this->targetDirs[1].'/includes/HotPath/C1.php';
+        $this->privates['service_container'] = function () {
+            include_once $this->targetDirs[1].'/includes/HotPath/I1.php';
+            include_once $this->targetDirs[1].'/includes/HotPath/P1.php';
+            include_once $this->targetDirs[1].'/includes/HotPath/T1.php';
+            include_once $this->targetDirs[1].'/includes/HotPath/C1.php';
+        };
     }
 
     public function reset()

Tests/Fixtures/yaml/null_config.yml

@@ -0,0 +1 @@
+project: ~

Tests/Loader/YamlFileLoaderTest.php

@@ -221,6 +221,17 @@ public function testExtensions()
         }
     }
 
+    public function testExtensionWithNullConfig()
+    {
+        $container = new ContainerBuilder();
+        $container->registerExtension(new \ProjectExtension());
+        $loader = new YamlFileLoader($container, new FileLocator(self::$fixturesPath.'/yaml'));
+        $loader->load('null_config.yml');
+        $container->compile();
+
+        $this->assertSame(array(null), $container->getParameter('project.configs'));
+    }
+
     public function testSupports()
     {
         $loader = new YamlFileLoader(new ContainerBuilder(), new FileLocator());