Merge branch '4.2' into 4.3

* 4.2:
  [HttpFoundation] Throw exception when the \"session\" extension is not loaded
  remove invalid test cases
  [Serializer] Fixed PHP of DenormalizableInterface::denormalize
  [Cache] work aroung PHP memory leak
  [Finder] docblock fixes
  pass error code as a string
  Catch JsonException and rethrow in JsonEncode

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -225,6 +225,10 @@ class FrameworkExtension extends Extension
         }
 
         if ($this->isConfigEnabled($container, $config['session'])) {
+            if (!\extension_loaded('session')) {
+                throw new \LogicException('PHP extension "session" is required.');
+            }
+
             $this->sessionConfigEnabled = true;
             $this->registerSessionConfiguration($config['session'], $container, $loader);
             if (!empty($config['test'])) {

src/Symfony/Component/Cache/Traits/PhpFilesTrait.php

@@ -50,12 +50,15 @@ trait PhpFilesTrait
     {
         $time = time();
         $pruned = true;
+        $getExpiry = true;
 
         set_error_handler($this->includeHandler);
         try {
             foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->directory, \FilesystemIterator::SKIP_DOTS), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
                 try {
-                    list($expiresAt) = include $file;
+                    if (\is_array($expiresAt = include $file)) {
+                        $expiresAt = $expiresAt[0];
+                    }
                 } catch (\ErrorException $e) {
                     $expiresAt = $time;
                 }
@@ -87,15 +90,21 @@ trait PhpFilesTrait
         $values = [];
 
         begin:
+        $getExpiry = false;
+
         foreach ($ids as $id) {
             if (null === $value = $this->values[$id] ?? null) {
                 $missingIds[] = $id;
             } elseif ('N;' === $value) {
                 $values[$id] = null;
-            } elseif ($value instanceof \Closure) {
-                $values[$id] = $value();
-            } else {
+            } elseif (!\is_object($value)) {
                 $values[$id] = $value;
+            } elseif (!$value instanceof LazyValue) {
+                // calling a Closure is for @deprecated BC and should be removed in Symfony 5.0
+                $values[$id] = $value();
+            } elseif (false === $values[$id] = include $value->file) {
+                unset($values[$id], $this->values[$id]);
+                $missingIds[] = $id;
             }
             if (!$this->appendOnly) {
                 unset($this->values[$id]);
@@ -108,10 +117,18 @@ trait PhpFilesTrait
 
         set_error_handler($this->includeHandler);
         try {
+            $getExpiry = true;
+
             foreach ($missingIds as $k => $id) {
                 try {
                     $file = $this->files[$id] ?? $this->files[$id] = $this->getFile($id);
-                    list($expiresAt, $this->values[$id]) = include $file;
+
+                    if (\is_array($expiresAt = include $file)) {
+                        [$expiresAt, $this->values[$id]] = $expiresAt;
+                    } elseif ($now < $expiresAt) {
+                        $this->values[$id] = new LazyValue($file);
+                    }
+
                     if ($now >= $expiresAt) {
                         unset($this->values[$id], $missingIds[$k]);
                     }
@@ -140,7 +157,13 @@ trait PhpFilesTrait
         set_error_handler($this->includeHandler);
         try {
             $file = $this->files[$id] ?? $this->files[$id] = $this->getFile($id);
-            list($expiresAt, $value) = include $file;
+            $getExpiry = true;
+
+            if (\is_array($expiresAt = include $file)) {
+                [$expiresAt, $value] = $expiresAt;
+            } elseif ($this->appendOnly) {
+                $value = new LazyValue($file);
+            }
         } catch (\ErrorException $e) {
             return false;
         } finally {
@@ -189,13 +212,16 @@ trait PhpFilesTrait
             }
 
             if (!$isStaticValue) {
-                $value = str_replace("\n", "\n    ", $value);
-                $value = "static function () {\n\n    return {$value};\n\n}";
+                // We cannot use a closure here because of https://bugs.php.net/76982
+                $value = str_replace('\Symfony\Component\VarExporter\Internal\\', '', $value);
+                $value = "<?php\n\nnamespace Symfony\Component\VarExporter\Internal;\n\nreturn \$getExpiry ? {$expiry} : {$value};\n";
+            } else {
+                $value = "<?php return [{$expiry}, {$value}];\n";
             }
 
             $file = $this->files[$key] = $this->getFile($key, true);
             // Since OPcache only compiles files older than the script execution start, set the file's mtime in the past
-            $ok = $this->write($file, "<?php return [{$expiry}, {$value}];\n", self::$startTime - 10) && $ok;
+            $ok = $this->write($file, $value, self::$startTime - 10) && $ok;
 
             if ($allowCompile) {
                 @opcache_invalidate($file, true);
@@ -241,3 +267,16 @@ trait PhpFilesTrait
         return @unlink($file);
     }
 }
+
+/**
+ * @internal
+ */
+class LazyValue
+{
+    public $file;
+
+    public function __construct($file)
+    {
+        $this->file = $file;
+    }
+}

src/Symfony/Component/Finder/Finder.php

@@ -582,7 +582,7 @@ class Finder implements \IteratorAggregate, \Countable
     /**
      * Searches files and directories which match defined rules.
      *
-     * @param string|array $dirs A directory path or an array of directories
+     * @param string|string[] $dirs A directory path or an array of directories
      *
      * @return $this
      *

src/Symfony/Component/Finder/Iterator/ExcludeDirectoryFilterIterator.php

@@ -25,7 +25,7 @@ class ExcludeDirectoryFilterIterator extends \FilterIterator implements \Recursi
 
     /**
      * @param \Iterator $iterator    The Iterator to filter
-     * @param array     $directories An array of directories to exclude
+     * @param string[]  $directories An array of directories to exclude
      */
     public function __construct(\Iterator $iterator, array $directories)
     {

src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php

@@ -103,6 +103,10 @@ class NativeSessionStorage implements SessionStorageInterface
      */
     public function __construct(array $options = [], $handler = null, MetadataBag $metaBag = null)
     {
+        if (!\extension_loaded('session')) {
+            throw new \LogicException('PHP extension "session" is required.');
+        }
+
         $options += [
             'cache_limiter' => '',
             'cache_expire' => 0,

src/Symfony/Component/HttpFoundation/Session/Storage/PhpBridgeSessionStorage.php

@@ -24,6 +24,10 @@ class PhpBridgeSessionStorage extends NativeSessionStorage
      */
     public function __construct($handler = null, MetadataBag $metaBag = null)
     {
+        if (!\extension_loaded('session')) {
+            throw new \LogicException('PHP extension "session" is required.');
+        }
+
         $this->setMetadataBag($metaBag);
         $this->setSaveHandler($handler);
     }

src/Symfony/Component/Serializer/Encoder/JsonEncode.php

@@ -47,14 +47,19 @@ class JsonEncode implements EncoderInterface
      */
     public function encode($data, $format, array $context = [])
     {
-        $jsonEncodeOptions = $context[self::OPTIONS] ?? $this->defaultContext[self::OPTIONS];
-        $encodedJson = json_encode($data, $jsonEncodeOptions);
+        $options = $context[self::OPTIONS] ?? $this->defaultContext[self::OPTIONS];
 
-        if (\PHP_VERSION_ID >= 70300 && (JSON_THROW_ON_ERROR & $jsonEncodeOptions)) {
+        try {
+            $encodedJson = json_encode($data, $options);
+        } catch (\JsonException $e) {
+            throw new NotEncodableValueException($e->getMessage(), 0, $e);
+        }
+
+        if (\PHP_VERSION_ID >= 70300 && (JSON_THROW_ON_ERROR & $options)) {
             return $encodedJson;
         }
 
-        if (JSON_ERROR_NONE !== json_last_error() && (false === $encodedJson || !($jsonEncodeOptions & JSON_PARTIAL_OUTPUT_ON_ERROR))) {
+        if (JSON_ERROR_NONE !== json_last_error() && (false === $encodedJson || !($options & JSON_PARTIAL_OUTPUT_ON_ERROR))) {
             throw new NotEncodableValueException(json_last_error_msg());
         }
 

src/Symfony/Component/Serializer/Normalizer/DenormalizableInterface.php

@@ -34,7 +34,7 @@ interface DenormalizableInterface
      *                                                  differently based on different input formats
      * @param array                       $context      Options for denormalizing
      *
-     * @return object
+     * @return object|object[]
      */
     public function denormalize(DenormalizerInterface $denormalizer, $data, $format = null, array $context = []);
 }

src/Symfony/Component/Validator/Tests/Constraints/AbstractComparisonValidatorTestCase.php

@@ -148,20 +148,6 @@ abstract class AbstractComparisonValidatorTestCase extends ConstraintValidatorTe
         $this->assertNoViolation();
     }
 
-    /**
-     * @dataProvider provideValidComparisonsToPropertyPath
-     */
-    public function testValidComparisonToPropertyPathOnArray($comparedValue)
-    {
-        $constraint = $this->createConstraint(['propertyPath' => '[root][value]']);
-
-        $this->setObject(['root' => ['value' => 5]]);
-
-        $this->validator->validate($comparedValue, $constraint);
-
-        $this->assertNoViolation();
-    }
-
     public function testNoViolationOnNullObjectWithPropertyPath()
     {
         $constraint = $this->createConstraint(['propertyPath' => 'propertyPath']);

src/Symfony/Component/Validator/Tests/Validator/AbstractTest.php

@@ -511,7 +511,7 @@ abstract class AbstractTest extends AbstractValidatorTest
                 ->setParameter('%param%', 'value')
                 ->setInvalidValue('Invalid value')
                 ->setPlural(2)
-                ->setCode(42)
+                ->setCode('42')
                 ->addViolation();
         };
 
@@ -528,7 +528,7 @@ abstract class AbstractTest extends AbstractValidatorTest
         $this->assertSame($entity, $violations[0]->getRoot());
         $this->assertSame('Invalid value', $violations[0]->getInvalidValue());
         $this->assertSame(2, $violations[0]->getPlural());
-        $this->assertSame(42, $violations[0]->getCode());
+        $this->assertSame('42', $violations[0]->getCode());
     }
 
     public function testNoDuplicateValidationIfClassConstraintInMultipleGroups()