Merge branch '3.4' into 4.0

* 3.4:
  [YAML] Issue #26065: leading spaces in YAML multi-line string literals
  [Bridge\PhpUnit] Exit as late as possible
  [Bridge\PhpUnit] Cleanup BC layer
  [PhpBridge] add PHPUnit 7 support to SymfonyTestsListener
  [Lock] Log already-locked errors as "notice" instead of "warning"
  add context to serialize and deserialize
  Update Repository Symlink Helper
  Document explicitly that dotfiles and vcs files are ignored by default
  [HttpKernel] don't try to wire Request argument with controller.service_arguments
  Make kernel build time optionally deterministic
  Use 0 for unlimited expiry
  [Routing] fix typo
  Bump default PHPUnit version from 6.3 to 6.5
  do not mock the container builder in tests
  [Cache][WebProfiler] fix collecting cache stats with sub-requests + allow clearing calls

Author: nicolas-grekas

CHANGELOG.md

@@ -21,6 +21,7 @@ CHANGELOG
  * added getter for extra attributes in `ExtraAttributesException`
  * improved `CsvEncoder` to handle variable nested structures
  * CSV headers can be passed to the `CsvEncoder` via the `csv_headers` serialization context variable 
+ * added `$context` when checking for encoding, decoding and normalizing in `Serializer`
 
 3.3.0
 -----

Serializer.php

@@ -98,11 +98,11 @@ public function __construct(array $normalizers = array(), array $encoders = arra
      */
     final public function serialize($data, $format, array $context = array())
     {
-        if (!$this->supportsEncoding($format)) {
+        if (!$this->supportsEncoding($format, $context)) {
             throw new NotEncodableValueException(sprintf('Serialization for the format %s is not supported', $format));
         }
 
-        if ($this->encoder->needsNormalization($format)) {
+        if ($this->encoder->needsNormalization($format, $context)) {
             $data = $this->normalize($data, $format, $context);
         }
 
@@ -114,7 +114,7 @@ final public function serialize($data, $format, array $context = array())
      */
     final public function deserialize($data, $type, $format, array $context = array())
     {
-        if (!$this->supportsDecoding($format)) {
+        if (!$this->supportsDecoding($format, $context)) {
             throw new NotEncodableValueException(sprintf('Deserialization for the format %s is not supported', $format));
         }