Merge branch '3.4'

* 3.4:
  [DI] Handle container.autowiring.strict_mode to opt-out from legacy autowiring
  [2.8] Fix some docblocks
  Escape trailing \ in QuestionHelper autocompletion
  [FrameworkBundle][Serializer] Remove outdated condition
  Add "doctrine/annotations" to top-level composer.json
  Fix phpdoc inconsistencies, simplify no-op sprintf.
  Remove inapplicable phpdoc comment
  nit: Fix phpdoc inconsistency and unreachable statement
  [DI] Register default env var provided types
  Fix phpdoc and unnecessary sprintf
  [FrameworkBundle][Workflow] Fix deprectation when checking workflow.registry service in dump command
  [Security] Fix BC layer for AbstractGuardAuthenticator subclasses
  Prefer line formatter on missing cli dumper
  [DI] Enhance service locator error message

Author: nicolas-grekas

Normalizer/AbstractObjectNormalizer.php

@@ -110,7 +110,7 @@ public function normalize($object, $format = null, array $context = array())
      *
      * @return string[]
      */
-    protected function getAttributes($object, $format = null, array $context)
+    protected function getAttributes($object, $format, array $context)
     {
         $class = get_class($object);
         $key = $class.'-'.$context['cache_key'];

Tests/Encoder/ChainEncoderTest.php

@@ -13,6 +13,7 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Serializer\Encoder\ChainEncoder;
+use Symfony\Component\Serializer\Encoder\EncoderInterface;
 use Symfony\Component\Serializer\Encoder\NormalizationAwareInterface;
 
 class ChainEncoderTest extends TestCase
@@ -123,10 +124,14 @@ class ChainNormalizationAwareEncoder extends ChainEncoder implements Normalizati
 {
 }
 
-class NormalizationAwareEncoder implements NormalizationAwareInterface
+class NormalizationAwareEncoder implements EncoderInterface, NormalizationAwareInterface
 {
     public function supportsEncoding($format)
     {
         return true;
     }
+
+    public function encode($data, $format, array $context = array())
+    {
+    }
 }