Merge branch '3.4' into 4.1

* 3.4:
  Think positive
  KernelInterface can return null container
  [DI] Detect circular references with ChildDefinition parent
  [VarDumper] Fix global dump function return value for PHP7
  [Ldap] Use shut up operator on connection errors at ldap_start_tls
  Implement startTest rather than startTestSuite
  [OptionsResolver] remove dead code and useless else
  [HttpFoundation] don't override StreamedResponse::setNotModified()
  Added relevent links for parsing to the phpdoc
  Add stricter checking for valid date time string
  Fix symfony/console (optional) dependency for MonologBridge
  [Form] Fix DateTimeType html5 input format

Author: nicolas-grekas

Compiler/ResolveChildDefinitionsPass.php

@@ -15,6 +15,7 @@
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Exception\ExceptionInterface;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
+use Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException;
 
 /**
  * This replaces all ChildDefinition instances with their equivalent fully
@@ -25,6 +26,8 @@
  */
 class ResolveChildDefinitionsPass extends AbstractRecursivePass
 {
+    private $currentPath;
+
     protected function processValue($value, $isRoot = false)
     {
         if (!$value instanceof Definition) {
@@ -36,6 +39,7 @@ protected function processValue($value, $isRoot = false)
             $value = $this->container->getDefinition($this->currentId);
         }
         if ($value instanceof ChildDefinition) {
+            $this->currentPath = array();
             $value = $this->resolveDefinition($value);
             if ($isRoot) {
                 $this->container->setDefinition($this->currentId, $value);
@@ -56,6 +60,8 @@ private function resolveDefinition(ChildDefinition $definition)
     {
         try {
             return $this->doResolveDefinition($definition);
+        } catch (ServiceCircularReferenceException $e) {
+            throw $e;
         } catch (ExceptionInterface $e) {
             $r = new \ReflectionProperty($e, 'message');
             $r->setAccessible(true);
@@ -71,6 +77,13 @@ private function doResolveDefinition(ChildDefinition $definition)
             throw new RuntimeException(sprintf('Parent definition "%s" does not exist.', $parent));
         }
 
+        $searchKey = array_search($parent, $this->currentPath);
+        $this->currentPath[] = $parent;
+
+        if (false !== $searchKey) {
+            throw new ServiceCircularReferenceException($parent, \array_slice($this->currentPath, $searchKey));
+        }
+
         $parentDef = $this->container->findDefinition($parent);
         if ($parentDef instanceof ChildDefinition) {
             $id = $this->currentId;

Tests/Compiler/ResolveChildDefinitionsPassTest.php

@@ -396,4 +396,21 @@ protected function process(ContainerBuilder $container)
         $pass = new ResolveChildDefinitionsPass();
         $pass->process($container);
     }
+
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException
+     * @expectedExceptionMessageRegExp /^Circular reference detected for service "c", path: "c -> b -> a -> c"./
+     */
+    public function testProcessDetectsChildDefinitionIndirectCircularReference()
+    {
+        $container = new ContainerBuilder();
+
+        $container->register('a');
+
+        $container->setDefinition('b', new ChildDefinition('a'));
+        $container->setDefinition('c', new ChildDefinition('b'));
+        $container->setDefinition('a', new ChildDefinition('c'));
+
+        $this->process($container);
+    }
 }