[DependencyInjection] extensions should only load if called during configuration

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

@@ -30,10 +30,15 @@ class MergeExtensionConfigurationPass implements CompilerPassInterface
         $aliases = $container->getAliases();
 
         foreach ($container->getExtensions() as $name => $extension) {
+            if (!$config = $container->getExtensionConfig($name)) {
+                // this extension was not called
+                continue;
+            }
+
             $tmpContainer = new ContainerBuilder($container->getParameterBag());
             $tmpContainer->addObjectResource($extension);
 
-            $extension->load($container->getExtensionConfig($name), $tmpContainer);
+            $extension->load($config, $tmpContainer);
 
             $container->merge($tmpContainer);
         }

src/Symfony/Component/DependencyInjection/ContainerBuilder.php

@@ -46,6 +46,8 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
     public function __construct(ParameterBagInterface $parameterBag = null)
     {
         parent::__construct($parameterBag);
+
+        $this->compiler = new Compiler();
     }
 
     /**
@@ -166,47 +168,35 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
     }
 
     /**
-     * Adds a compiler pass at the end of the current passes
+     * Adds a compiler pass.
      *
-     * @param CompilerPassInterface $pass
-     * @param string                $type
+     * @param CompilerPassInterface $pass A compiler pass
+     * @param string                $type The type of compiler pass
      */
     public function addCompilerPass(CompilerPassInterface $pass, $type = PassConfig::TYPE_BEFORE_OPTIMIZATION)
     {
-        if (null === $this->compiler) {
-            $this->initializeCompiler();
-        }
-
         $this->compiler->addPass($pass, $type);
 
         $this->addObjectResource($pass);
     }
 
     /**
-     * Returns the compiler pass config which can then be modified
+     * Returns the compiler pass config which can then be modified.
      *
-     * @return PassConfig
+     * @return PassConfig The compiler pass config
      */
     public function getCompilerPassConfig()
     {
-        if (null === $this->compiler) {
-            $this->initializeCompiler();
-        }
-
         return $this->compiler->getPassConfig();
     }
 
     /**
-     * Returns the compiler instance
+     * Returns the compiler.
      *
-     * @return Compiler
+     * @return Compiler The compiler
      */
     public function getCompiler()
     {
-        if (null === $this->compiler) {
-            $this->initializeCompiler();
-        }
-
         return $this->compiler;
     }
 
@@ -379,7 +369,7 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
     public function getExtensionConfig($name)
     {
         if (!isset($this->extensionConfigs[$name])) {
-            return array(array());
+            $this->extensionConfigs[$name] = array();
         }
 
         return $this->extensionConfigs[$name];
@@ -401,8 +391,8 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
      */
     public function compile()
     {
-        if (null === $this->compiler) {
-            $this->initializeCompiler();
+        foreach ($this->compiler->getPassConfig()->getPasses() as $pass) {
+            $this->addObjectResource($pass);
         }
 
         $this->compiler->compile($this);
@@ -836,19 +826,6 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
         return $tags;
     }
 
-    /**
-     * Initializes the compiler
-     *
-     * @return void
-     */
-    protected function initializeCompiler()
-    {
-        $this->compiler = new Compiler();
-        foreach ($this->compiler->getPassConfig()->getPasses() as $pass) {
-            $this->addObjectResource($pass);
-        }
-    }
-
     /**
      * Returns the Service Conditionals.
      *

tests/Symfony/Tests/Component/DependencyInjection/ContainerBuilderTest.php

@@ -447,6 +447,29 @@ class ContainerBuilderTest extends \PHPUnit_Framework_TestCase
         $container->getExtension('no_registered');
     }
 
+    public function testRegisteredButNotLoadedExtension()
+    {
+        $extension = $this->getMock('Symfony\\Component\\DependencyInjection\\Extension\\ExtensionInterface');
+        $extension->expects($this->once())->method('getAlias')->will($this->returnValue('project'));
+        $extension->expects($this->never())->method('load');
+
+        $container = new ContainerBuilder();
+        $container->registerExtension($extension);
+        $container->compile();
+    }
+
+    public function testRegisteredAndLoadedExtension()
+    {
+        $extension = $this->getMock('Symfony\\Component\\DependencyInjection\\Extension\\ExtensionInterface');
+        $extension->expects($this->exactly(2))->method('getAlias')->will($this->returnValue('project'));
+        $extension->expects($this->once())->method('load')->with(array(array('foo' => 'bar')));
+
+        $container = new ContainerBuilder();
+        $container->registerExtension($extension);
+        $container->loadFromExtension('project', array('foo' => 'bar'));
+        $container->compile();
+    }
+
     /**
      * @covers Symfony\Component\DependencyInjection\ContainerBuilder::addInterfaceInjector
      * @covers Symfony\Component\DependencyInjection\ContainerBuilder::addInterfaceInjectors