Merge branch '2.1' into 2.2

* 2.1:
  fixed a circular call (closes #6864)
  Correct comment in NativeSessionStorage regarding session.save_handler
  [Security] Add PHPDoc to AuthenticationEvents

Author: fabpot

Dumper/PhpDumper.php

@@ -958,23 +958,25 @@ private function getDefinitionsFromArguments(array $arguments)
      *
      * @return Boolean
      */
-    private function hasReference($id, array $arguments, $deep = false)
+    private function hasReference($id, array $arguments, $deep = false, $visited = array())
     {
         foreach ($arguments as $argument) {
             if (is_array($argument)) {
-                if ($this->hasReference($id, $argument, $deep)) {
+                if ($this->hasReference($id, $argument, $deep, $visited)) {
                     return true;
                 }
             } elseif ($argument instanceof Reference) {
                 if ($id === (string) $argument) {
                     return true;
                 }
 
-                if ($deep) {
+                if ($deep && !isset($visited[(string) $argument])) {
+                    $visited[(string) $argument] = true;
+
                     $service = $this->container->getDefinition((string) $argument);
                     $arguments = array_merge($service->getMethodCalls(), $service->getArguments(), $service->getProperties());
 
-                    if ($this->hasReference($id, $arguments, $deep)) {
+                    if ($this->hasReference($id, $arguments, $deep, $visited)) {
                         return true;
                     }
                 }