Merge branch '3.4' into 4.3

* 3.4:
  Fix return statements
  [TwigBridge] add missing dep
  Add false type to ChoiceListFactoryInterface::createView $label argument

src/Symfony/Bridge/Doctrine/Form/ChoiceList/IdReader.php

@@ -91,7 +91,7 @@ class IdReader
     public function getIdValue($object)
     {
         if (!$object) {
-            return;
+            return null;
         }
 
         if (!$this->om->contains($object)) {

src/Symfony/Bridge/Doctrine/Form/DoctrineOrmTypeGuesser.php

@@ -99,7 +99,7 @@ class DoctrineOrmTypeGuesser implements FormTypeGuesserInterface
         $classMetadatas = $this->getMetadata($class);
 
         if (!$classMetadatas) {
-            return;
+            return null;
         }
 
         /** @var ClassMetadataInfo $classMetadata */

src/Symfony/Bridge/Twig/AppVariable.php

@@ -68,7 +68,7 @@ class AppVariable
     /**
      * Returns the current user.
      *
-     * @return mixed
+     * @return object|null
      *
      * @see TokenInterface::getUser()
      */
@@ -79,7 +79,7 @@ class AppVariable
         }
 
         if (!$token = $tokenStorage->getToken()) {
-            return;
+            return null;
         }
 
         $user = $token->getUser();

src/Symfony/Bridge/Twig/composer.json

@@ -22,6 +22,7 @@
     },
     "require-dev": {
         "egulias/email-validator": "^2.0",
+        "fig/link-util": "^1.0",
         "symfony/asset": "~3.4|~4.0",
         "symfony/dependency-injection": "~3.4|~4.0",
         "symfony/finder": "~3.4|~4.0",

src/Symfony/Bundle/FrameworkBundle/Controller/ControllerTrait.php

@@ -351,7 +351,7 @@ trait ControllerTrait
     /**
      * Get a user from the Security Token Storage.
      *
-     * @return mixed
+     * @return object|null
      *
      * @throws \LogicException If SecurityBundle is not available
      *
@@ -366,12 +366,12 @@ trait ControllerTrait
         }
 
         if (null === $token = $this->container->get('security.token_storage')->getToken()) {
-            return;
+            return null;
         }
 
         if (!\is_object($user = $token->getUser())) {
             // e.g. anonymous authentication
-            return;
+            return null;
         }
 
         return $user;

src/Symfony/Bundle/FrameworkBundle/Templating/GlobalVariables.php

@@ -40,7 +40,7 @@ class GlobalVariables
     public function getToken()
     {
         if (!$this->container->has('security.token_storage')) {
-            return;
+            return null;
         }
 
         return $this->container->get('security.token_storage')->getToken();

src/Symfony/Bundle/FrameworkBundle/Templating/Helper/CodeHelper.php

@@ -126,7 +126,7 @@ class CodeHelper extends Helper
 
                 // Check if the file is an application/octet-stream (eg. Phar file) because highlight_file cannot parse these files
                 if ('application/octet-stream' === $finfo->file($file, FILEINFO_MIME_TYPE)) {
-                    return;
+                    return '';
                 }
             }
 

src/Symfony/Component/BrowserKit/Client.php

@@ -533,7 +533,7 @@ abstract class Client
     protected function createCrawlerFromContent($uri, $content, $type)
     {
         if (!class_exists('Symfony\Component\DomCrawler\Crawler')) {
-            return;
+            return null;
         }
 
         $crawler = new Crawler(null, $uri);

src/Symfony/Component/Config/Util/XmlUtils.php

@@ -219,7 +219,7 @@ class XmlUtils
 
         switch (true) {
             case 'null' === $lowercaseValue:
-                return;
+                return null;
             case ctype_digit($value):
                 $raw = $value;
                 $cast = (int) $value;

src/Symfony/Component/Console/Application.php

@@ -472,7 +472,7 @@ class Application
         if (!$command->isEnabled()) {
             $command->setApplication(null);
 
-            return;
+            return null;
         }
 
         if (null === $command->getDefinition()) {

src/Symfony/Component/CssSelector/Parser/TokenStream.php

@@ -155,7 +155,7 @@ class TokenStream
         }
 
         if ($next->isDelimiter(['*'])) {
-            return;
+            return null;
         }
 
         throw SyntaxErrorException::unexpectedToken('identifier or "*"', $next);

src/Symfony/Component/Debug/ErrorHandler.php

@@ -443,7 +443,7 @@ class ErrorHandler
                 self::$silencedErrorCache[$id][$message] = $errorAsException;
             }
             if (null === $lightTrace) {
-                return;
+                return true;
             }
         } else {
             $errorAsException = new \ErrorException($logMessage, 0, $type, $file, $line);

src/Symfony/Component/Debug/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php

@@ -33,11 +33,11 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
         $notFoundSuffix = '\' not found';
         $notFoundSuffixLen = \strlen($notFoundSuffix);
         if ($notFoundSuffixLen > $messageLen) {
-            return;
+            return null;
         }
 
         if (0 !== substr_compare($error['message'], $notFoundSuffix, -$notFoundSuffixLen)) {
-            return;
+            return null;
         }
 
         foreach (['class', 'interface', 'trait'] as $typeName) {

src/Symfony/Component/Debug/FatalErrorHandler/UndefinedFunctionFatalErrorHandler.php

@@ -30,17 +30,17 @@ class UndefinedFunctionFatalErrorHandler implements FatalErrorHandlerInterface
         $notFoundSuffix = '()';
         $notFoundSuffixLen = \strlen($notFoundSuffix);
         if ($notFoundSuffixLen > $messageLen) {
-            return;
+            return null;
         }
 
         if (0 !== substr_compare($error['message'], $notFoundSuffix, -$notFoundSuffixLen)) {
-            return;
+            return null;
         }
 
         $prefix = 'Call to undefined function ';
         $prefixLen = \strlen($prefix);
         if (0 !== strpos($error['message'], $prefix)) {
-            return;
+            return null;
         }
 
         $fullyQualifiedFunctionName = substr($error['message'], $prefixLen, -$notFoundSuffixLen);

src/Symfony/Component/Debug/FatalErrorHandler/UndefinedMethodFatalErrorHandler.php

@@ -28,7 +28,7 @@ class UndefinedMethodFatalErrorHandler implements FatalErrorHandlerInterface
     {
         preg_match('/^Call to undefined method (.*)::(.*)\(\)$/', $error['message'], $matches);
         if (!$matches) {
-            return;
+            return null;
         }
 
         $className = $matches[1];

src/Symfony/Component/DependencyInjection/LazyProxy/ProxyHelper.php

@@ -29,7 +29,7 @@ class ProxyHelper
             $type = $r->getReturnType();
         }
         if (!$type) {
-            return;
+            return null;
         }
         if (!\is_string($type)) {
             $name = $type->getName();
@@ -45,7 +45,7 @@ class ProxyHelper
             return $prefix.$name;
         }
         if (!$r instanceof \ReflectionMethod) {
-            return;
+            return null;
         }
         if ('self' === $lcName) {
             return $prefix.$r->getDeclaringClass()->name;

src/Symfony/Component/Filesystem/Filesystem.php

@@ -414,12 +414,12 @@ class Filesystem
     public function readlink($path, $canonicalize = false)
     {
         if (!$canonicalize && !is_link($path)) {
-            return;
+            return null;
         }
 
         if ($canonicalize) {
             if (!$this->exists($path)) {
-                return;
+                return null;
             }
 
             if ('\\' === \DIRECTORY_SEPARATOR) {

src/Symfony/Component/Form/ChoiceList/Factory/ChoiceListFactoryInterface.php

@@ -78,14 +78,11 @@ interface ChoiceListFactoryInterface
      * attributes that should be added to the respective choice.
      *
      * @param array|callable|null $preferredChoices The preferred choices
-     * @param callable|null       $label            The callable generating the
+     * @param callable|false|null $label            The callable generating the choice labels;
-     *                                              choice labels
+     *                                              pass false to discard the label
-     * @param callable|null       $index            The callable generating the
+     * @param callable|null       $index            The callable generating the view indices
-     *                                              view indices
+     * @param callable|null       $groupBy          The callable generating the group names
-     * @param callable|null       $groupBy          The callable generating the
+     * @param array|callable|null $attr             The callable generating the HTML attributes
-     *                                              group names
-     * @param array|callable|null $attr             The callable generating the
-     *                                              HTML attributes
      *
      * @return ChoiceListView The choice list view
      */

src/Symfony/Component/Form/Extension/Core/DataTransformer/BooleanToStringTransformer.php

@@ -45,14 +45,14 @@ class BooleanToStringTransformer implements DataTransformerInterface
      *
      * @param bool $value Boolean value
      *
-     * @return string String value
+     * @return string|null String value
      *
      * @throws TransformationFailedException if the given value is not a Boolean
      */
     public function transform($value)
     {
         if (null === $value) {
-            return;
+            return null;
         }
 
         if (!\is_bool($value)) {

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateIntervalToArrayTransformer.php

@@ -106,7 +106,7 @@ class DateIntervalToArrayTransformer implements DataTransformerInterface
      *
      * @param array $value Interval array
      *
-     * @return \DateInterval Normalized date interval
+     * @return \DateInterval|null Normalized date interval
      *
      * @throws UnexpectedTypeException       if the given value is not an array
      * @throws TransformationFailedException if the value could not be transformed
@@ -114,13 +114,13 @@ class DateIntervalToArrayTransformer implements DataTransformerInterface
     public function reverseTransform($value)
     {
         if (null === $value) {
-            return;
+            return null;
         }
         if (!\is_array($value)) {
             throw new UnexpectedTypeException($value, 'array');
         }
         if ('' === implode('', $value)) {
-            return;
+            return null;
         }
         $emptyFields = [];
         foreach ($this->fields as $field) {

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateIntervalToStringTransformer.php

@@ -62,7 +62,7 @@ class DateIntervalToStringTransformer implements DataTransformerInterface
      *
      * @param string $value An ISO 8601 or date string like date interval presentation
      *
-     * @return \DateInterval An instance of \DateInterval
+     * @return \DateInterval|null An instance of \DateInterval
      *
      * @throws UnexpectedTypeException       if the given value is not a string
      * @throws TransformationFailedException if the date interval could not be parsed
@@ -70,13 +70,13 @@ class DateIntervalToStringTransformer implements DataTransformerInterface
     public function reverseTransform($value)
     {
         if (null === $value) {
-            return;
+            return null;
         }
         if (!\is_string($value)) {
             throw new UnexpectedTypeException($value, 'string');
         }
         if ('' === $value) {
-            return;
+            return null;
         }
         if (!$this->isISO8601($value)) {
             throw new TransformationFailedException('Non ISO 8601 date strings are not supported yet');

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToArrayTransformer.php

@@ -103,7 +103,7 @@ class DateTimeToArrayTransformer extends BaseDateTimeTransformer
      *
      * @param array $value Localized date
      *
-     * @return \DateTime Normalized date
+     * @return \DateTime|null Normalized date
      *
      * @throws TransformationFailedException If the given value is not an array,
      *                                       if the value could not be transformed
@@ -111,7 +111,7 @@ class DateTimeToArrayTransformer extends BaseDateTimeTransformer
     public function reverseTransform($value)
     {
         if (null === $value) {
-            return;
+            return null;
         }
 
         if (!\is_array($value)) {
@@ -119,7 +119,7 @@ class DateTimeToArrayTransformer extends BaseDateTimeTransformer
         }
 
         if ('' === implode('', $value)) {
-            return;
+            return null;
         }
 
         $emptyFields = [];

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToHtml5LocalDateTimeTransformer.php

@@ -66,7 +66,7 @@ class DateTimeToHtml5LocalDateTimeTransformer extends BaseDateTimeTransformer
      *
      * @param string $dateTimeLocal Formatted string
      *
-     * @return \DateTime Normalized date
+     * @return \DateTime|null Normalized date
      *
      * @throws TransformationFailedException If the given value is not a string,
      *                                       if the value could not be transformed
@@ -78,7 +78,7 @@ class DateTimeToHtml5LocalDateTimeTransformer extends BaseDateTimeTransformer
         }
 
         if ('' === $dateTimeLocal) {
-            return;
+            return null;
         }
 
         // to maintain backwards compatibility we do not strictly validate the submitted date

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToLocalizedStringTransformer.php

@@ -99,7 +99,7 @@ class DateTimeToLocalizedStringTransformer extends BaseDateTimeTransformer
      *
      * @param string|array $value Localized date string/array
      *
-     * @return \DateTime Normalized date
+     * @return \DateTime|null Normalized date
      *
      * @throws TransformationFailedException if the given value is not a string,
      *                                       if the date could not be parsed
@@ -111,7 +111,7 @@ class DateTimeToLocalizedStringTransformer extends BaseDateTimeTransformer
         }
 
         if ('' === $value) {
-            return;
+            return null;
         }
 
         // date-only patterns require parsing to be done in UTC, as midnight might not exist in the local timezone due

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToRfc3339Transformer.php

@@ -53,7 +53,7 @@ class DateTimeToRfc3339Transformer extends BaseDateTimeTransformer
      *
      * @param string $rfc3339 Formatted string
      *
-     * @return \DateTime Normalized date
+     * @return \DateTime|null Normalized date
      *
      * @throws TransformationFailedException If the given value is not a string,
      *                                       if the value could not be transformed
@@ -65,7 +65,7 @@ class DateTimeToRfc3339Transformer extends BaseDateTimeTransformer
         }
 
         if ('' === $rfc3339) {
-            return;
+            return null;
         }
 
         if (!preg_match('/^(\d{4})-(\d{2})-(\d{2})T\d{2}:\d{2}(?::\d{2})?(?:\.\d+)?(?:Z|(?:(?:\+|-)\d{2}:\d{2}))$/', $rfc3339, $matches)) {

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToStringTransformer.php

@@ -101,7 +101,7 @@ class DateTimeToStringTransformer extends BaseDateTimeTransformer
      *
      * @param string $value A value as produced by PHP's date() function
      *
-     * @return \DateTime An instance of \DateTime
+     * @return \DateTime|null An instance of \DateTime
      *
      * @throws TransformationFailedException If the given value is not a string,
      *                                       or could not be transformed
@@ -109,7 +109,7 @@ class DateTimeToStringTransformer extends BaseDateTimeTransformer
     public function reverseTransform($value)
     {
         if (empty($value)) {
-            return;
+            return null;
         }
 
         if (!\is_string($value)) {

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToTimestampTransformer.php

@@ -26,14 +26,14 @@ class DateTimeToTimestampTransformer extends BaseDateTimeTransformer
      *
      * @param \DateTimeInterface $dateTime A DateTimeInterface object
      *
-     * @return int A timestamp
+     * @return int|null A timestamp
      *
      * @throws TransformationFailedException If the given value is not a \DateTimeInterface
      */
     public function transform($dateTime)
     {
         if (null === $dateTime) {
-            return;
+            return null;
         }
 
         if (!$dateTime instanceof \DateTimeInterface) {
@@ -48,7 +48,7 @@ class DateTimeToTimestampTransformer extends BaseDateTimeTransformer
      *
      * @param string $value A timestamp
      *
-     * @return \DateTime A \DateTime object
+     * @return \DateTime|null A \DateTime object
      *
      * @throws TransformationFailedException If the given value is not a timestamp
      *                                       or if the given timestamp is invalid
@@ -56,7 +56,7 @@ class DateTimeToTimestampTransformer extends BaseDateTimeTransformer
     public function reverseTransform($value)
     {
         if (null === $value) {
-            return;
+            return null;
         }
 
         if (!is_numeric($value)) {

src/Symfony/Component/Form/Extension/Core/DataTransformer/NumberToLocalizedStringTransformer.php

@@ -145,7 +145,7 @@ class NumberToLocalizedStringTransformer implements DataTransformerInterface
         }
 
         if ('' === $value) {
-            return;
+            return null;
         }
 
         if (\in_array($value, ['NaN', 'NAN', 'nan'], true)) {

src/Symfony/Component/Form/Extension/Core/DataTransformer/PercentToLocalizedStringTransformer.php

@@ -112,7 +112,7 @@ class PercentToLocalizedStringTransformer implements DataTransformerInterface
         }
 
         if ('' === $value) {
-            return;
+            return null;
         }
 
         $position = 0;

src/Symfony/Component/Form/Extension/Core/DataTransformer/ValueToDuplicatesTransformer.php

@@ -74,7 +74,7 @@ class ValueToDuplicatesTransformer implements DataTransformerInterface
         if (\count($emptyKeys) > 0) {
             if (\count($emptyKeys) == \count($this->keys)) {
                 // All keys empty
-                return;
+                return null;
             }
 
             throw new TransformationFailedException(sprintf('The keys "%s" should not be empty', implode('", "', $emptyKeys)));

src/Symfony/Component/Form/Extension/Validator/ViolationMapper/ViolationPath.php

@@ -134,7 +134,7 @@ class ViolationPath implements \IteratorAggregate, PropertyPathInterface
     public function getParent()
     {
         if ($this->length <= 1) {
-            return;
+            return null;
         }
 
         $parent = clone $this;

src/Symfony/Component/Form/Util/ServerParams.php

@@ -48,7 +48,7 @@ class ServerParams
         $iniMax = strtolower($this->getNormalizedIniPostMaxSize());
 
         if ('' === $iniMax) {
-            return;
+            return null;
         }
 
         $max = ltrim($iniMax, '+');

src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php

@@ -79,7 +79,7 @@ class FileBinaryMimeTypeGuesser implements MimeTypeGuesserInterface
         }
 
         if (!self::isSupported()) {
-            return;
+            return null;
         }
 
         ob_start();
@@ -89,14 +89,14 @@ class FileBinaryMimeTypeGuesser implements MimeTypeGuesserInterface
         if ($return > 0) {
             ob_end_clean();
 
-            return;
+            return null;
         }
 
         $type = trim(ob_get_clean());
 
         if (!preg_match('#^([a-z0-9\-]+/[a-z0-9\-\.]+)#i', $type, $match)) {
             // it's not a type, but an error message
-            return;
+            return null;
         }
 
         return $match[1];

src/Symfony/Component/HttpFoundation/File/MimeType/FileinfoMimeTypeGuesser.php

@@ -62,11 +62,11 @@ class FileinfoMimeTypeGuesser implements MimeTypeGuesserInterface
         }
 
         if (!self::isSupported()) {
-            return;
+            return null;
         }
 
         if (!$finfo = new \finfo(FILEINFO_MIME_TYPE, $this->magicFile)) {
-            return;
+            return null;
         }
 
         return $finfo->file($path);

src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeGuesserInterface.php

@@ -29,7 +29,7 @@ interface MimeTypeGuesserInterface
      *
      * @param string $path The path to the file
      *
-     * @return string The mime type or NULL, if none could be guessed
+     * @return string|null The mime type or NULL, if none could be guessed
      *
      * @throws FileNotFoundException If the file does not exist
      * @throws AccessDeniedException If the file could not be read

src/Symfony/Component/HttpFoundation/RequestStack.php

@@ -47,7 +47,7 @@ class RequestStack
     public function pop()
     {
         if (!$this->requests) {
-            return;
+            return null;
         }
 
         return array_pop($this->requests);
@@ -73,7 +73,7 @@ class RequestStack
     public function getMasterRequest()
     {
         if (!$this->requests) {
-            return;
+            return null;
         }
 
         return $this->requests[0];
@@ -95,7 +95,7 @@ class RequestStack
         $pos = \count($this->requests) - 2;
 
         if (!isset($this->requests[$pos])) {
-            return;
+            return null;
         }
 
         return $this->requests[$pos];

src/Symfony/Component/HttpKernel/EventListener/SessionListener.php

@@ -35,7 +35,7 @@ class SessionListener extends AbstractSessionListener
     protected function getSession()
     {
         if (!$this->container->has('session')) {
-            return;
+            return null;
         }
 
         if ($this->container->has('session_storage')

src/Symfony/Component/HttpKernel/EventListener/TestSessionListener.php

@@ -33,7 +33,7 @@ class TestSessionListener extends AbstractTestSessionListener
     protected function getSession()
     {
         if (!$this->container->has('session')) {
-            return;
+            return null;
         }
 
         return $this->container->get('session');

src/Symfony/Component/HttpKernel/Profiler/FileProfilerStorage.php

@@ -116,7 +116,7 @@ class FileProfilerStorage implements ProfilerStorageInterface
     public function read($token)
     {
         if (!$token || !file_exists($file = $this->getFilename($token))) {
-            return;
+            return null;
         }
 
         return $this->createProfileFromData($token, unserialize(file_get_contents($file)));
@@ -227,7 +227,7 @@ class FileProfilerStorage implements ProfilerStorageInterface
         $position = ftell($file);
 
         if (0 === $position) {
-            return;
+            return null;
         }
 
         while (true) {

src/Symfony/Component/HttpKernel/Profiler/Profiler.php

@@ -143,7 +143,7 @@ class Profiler implements ResetInterface
     public function collect(Request $request, Response $response, \Exception $exception = null)
     {
         if (false === $this->enabled) {
-            return;
+            return null;
         }
 
         $profile = new Profile(substr(hash('sha256', uniqid(mt_rand(), true)), 0, 6));

src/Symfony/Component/HttpKernel/Profiler/ProfilerStorageInterface.php

@@ -47,7 +47,7 @@ interface ProfilerStorageInterface
      *
      * @param string $token A token
      *
-     * @return Profile The profile associated with token
+     * @return Profile|null The profile associated with token
      */
     public function read($token);
 

src/Symfony/Component/Intl/Data/Generator/LocaleDataGenerator.php

@@ -79,7 +79,7 @@ class LocaleDataGenerator extends AbstractDataGenerator
         // Don't generate aliases, as they are resolved during runtime
         // Unless an alias is needed as fallback for de-duplication purposes
         if (isset($this->localeAliases[$displayLocale]) && !$this->generatingFallback) {
-            return;
+            return null;
         }
 
         // Generate locale names for all locales that have translations in
@@ -124,7 +124,7 @@ class LocaleDataGenerator extends AbstractDataGenerator
             $data['Names'] = array_diff($data['Names'], $fallbackData['Names']);
         }
         if (!$data['Names']) {
-            return;
+            return null;
         }
 
         return $data;

src/Symfony/Component/Intl/ResourceBundle/CurrencyBundle.php

@@ -42,7 +42,7 @@ class CurrencyBundle extends CurrencyDataProvider implements CurrencyBundleInter
         try {
             return $this->getSymbol($currency, $displayLocale);
         } catch (MissingResourceException $e) {
-            return;
+            return null;
         }
     }
 
@@ -54,7 +54,7 @@ class CurrencyBundle extends CurrencyDataProvider implements CurrencyBundleInter
         try {
             return $this->getName($currency, $displayLocale);
         } catch (MissingResourceException $e) {
-            return;
+            return null;
         }
     }
 

src/Symfony/Component/Intl/ResourceBundle/LanguageBundle.php

@@ -54,7 +54,7 @@ class LanguageBundle extends LanguageDataProvider implements LanguageBundleInter
         try {
             return $this->getName($language, $displayLocale);
         } catch (MissingResourceException $e) {
-            return;
+            return null;
         }
     }
 
@@ -78,7 +78,7 @@ class LanguageBundle extends LanguageDataProvider implements LanguageBundleInter
         try {
             return $this->scriptProvider->getName($script, $displayLocale);
         } catch (MissingResourceException $e) {
-            return;
+            return null;
         }
     }
 

src/Symfony/Component/Intl/ResourceBundle/LocaleBundle.php

@@ -43,7 +43,7 @@ class LocaleBundle extends LocaleDataProvider implements LocaleBundleInterface
         try {
             return $this->getName($locale, $displayLocale);
         } catch (MissingResourceException $e) {
-            return;
+            return null;
         }
     }
 

src/Symfony/Component/Intl/ResourceBundle/RegionBundle.php

@@ -42,7 +42,7 @@ class RegionBundle extends RegionDataProvider implements RegionBundleInterface
         try {
             return $this->getName($country, $displayLocale);
         } catch (MissingResourceException $e) {
-            return;
+            return null;
         }
     }
 

src/Symfony/Component/Intl/Util/Version.php

@@ -83,7 +83,7 @@ class Version
         }
 
         if (!preg_match('/^'.$pattern.'/', $version, $matches)) {
-            return;
+            return null;
         }
 
         return $matches[0];

src/Symfony/Component/Process/Process.php

@@ -753,7 +753,7 @@ class Process implements \IteratorAggregate
     public function getExitCodeText()
     {
         if (null === $exitcode = $this->getExitCode()) {
-            return;
+            return null;
         }
 
         return isset(self::$exitCodes[$exitcode]) ? self::$exitCodes[$exitcode] : 'Unknown error';

src/Symfony/Component/PropertyAccess/PropertyPath.php

@@ -136,7 +136,7 @@ class PropertyPath implements \IteratorAggregate, PropertyPathInterface
     public function getParent()
     {
         if ($this->length <= 1) {
-            return;
+            return null;
         }
 
         $parent = clone $this;

src/Symfony/Component/PropertyAccess/PropertyPathInterface.php

@@ -40,7 +40,7 @@ interface PropertyPathInterface extends \Traversable
      *
      * If this property path only contains one item, null is returned.
      *
-     * @return PropertyPath The parent path or null
+     * @return PropertyPath|null The parent path or null
      */
     public function getParent();
 

src/Symfony/Component/PropertyInfo/Extractor/PhpDocExtractor.php

@@ -73,7 +73,7 @@ class PhpDocExtractor implements PropertyDescriptionExtractorInterface, Property
         /** @var $docBlock DocBlock */
         list($docBlock) = $this->getDocBlock($class, $property);
         if (!$docBlock) {
-            return;
+            return null;
         }
 
         $shortDescription = $docBlock->getSummary();
@@ -99,7 +99,7 @@ class PhpDocExtractor implements PropertyDescriptionExtractorInterface, Property
         /** @var $docBlock DocBlock */
         list($docBlock) = $this->getDocBlock($class, $property);
         if (!$docBlock) {
-            return;
+            return null;
         }
 
         $contents = $docBlock->getDescription()->render();
@@ -115,7 +115,7 @@ class PhpDocExtractor implements PropertyDescriptionExtractorInterface, Property
         /** @var $docBlock DocBlock */
         list($docBlock, $source, $prefix) = $this->getDocBlock($class, $property);
         if (!$docBlock) {
-            return;
+            return null;
         }
 
         switch ($source) {
@@ -141,7 +141,7 @@ class PhpDocExtractor implements PropertyDescriptionExtractorInterface, Property
         }
 
         if (!isset($types[0])) {
-            return;
+            return null;
         }
 
         if (!\in_array($prefix, $this->arrayMutatorPrefixes)) {

src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php

@@ -80,7 +80,7 @@ class ReflectionExtractor implements PropertyListExtractorInterface, PropertyTyp
         try {
             $reflectionClass = new \ReflectionClass($class);
         } catch (\ReflectionException $e) {
-            return;
+            return null;
         }
 
         $propertyFlags = 0;

src/Symfony/Component/PropertyInfo/Extractor/SerializerExtractor.php

@@ -36,11 +36,11 @@ class SerializerExtractor implements PropertyListExtractorInterface
     public function getProperties($class, array $context = [])
     {
         if (!isset($context['serializer_groups']) || !\is_array($context['serializer_groups'])) {
-            return;
+            return null;
         }
 
         if (!$this->classMetadataFactory->getMetadataFor($class)) {
-            return;
+            return null;
         }
 
         $properties = [];

src/Symfony/Component/Routing/Loader/AnnotationFileLoader.php

@@ -46,7 +46,7 @@ class AnnotationFileLoader extends FileLoader
      * @param string      $file A PHP file path
      * @param string|null $type The resource type
      *
-     * @return RouteCollection A RouteCollection instance
+     * @return RouteCollection|null A RouteCollection instance
      *
      * @throws \InvalidArgumentException When the file does not exist or its routes cannot be parsed
      */
@@ -58,7 +58,7 @@ class AnnotationFileLoader extends FileLoader
         if ($class = $this->findClass($path)) {
             $refl = new \ReflectionClass($class);
             if ($refl->isAbstract()) {
-                return;
+                return null;
             }
 
             $collection->addResource(new FileResource($path));

src/Symfony/Component/Security/Csrf/TokenStorage/NativeSessionTokenStorage.php

@@ -88,7 +88,7 @@ class NativeSessionTokenStorage implements ClearableTokenStorageInterface
         }
 
         if (!isset($_SESSION[$this->namespace][$tokenId])) {
-            return;
+            return null;
         }
 
         $token = (string) $_SESSION[$this->namespace][$tokenId];

src/Symfony/Component/Security/Http/ParameterBagUtils.php

@@ -45,7 +45,7 @@ final class ParameterBagUtils
         $root = substr($path, 0, $pos);
 
         if (null === $value = $parameters->get($root)) {
-            return;
+            return null;
         }
 
         if (null === self::$propertyAccessor) {
@@ -55,7 +55,7 @@ final class ParameterBagUtils
         try {
             return self::$propertyAccessor->getValue($value, substr($path, $pos));
         } catch (AccessException $e) {
-            return;
+            return null;
         }
     }
 
@@ -80,7 +80,7 @@ final class ParameterBagUtils
         $root = substr($path, 0, $pos);
 
         if (null === $value = $request->get($root)) {
-            return;
+            return null;
         }
 
         if (null === self::$propertyAccessor) {
@@ -90,7 +90,7 @@ final class ParameterBagUtils
         try {
             return self::$propertyAccessor->getValue($value, substr($path, $pos));
         } catch (AccessException $e) {
-            return;
+            return null;
         }
     }
 }

src/Symfony/Component/Validator/Constraints/Regex.php

@@ -82,7 +82,7 @@ class Regex extends Constraint
 
         // Quit if delimiters not at very beginning/end (e.g. when options are passed)
         if ($this->pattern[0] !== $this->pattern[\strlen($this->pattern) - 1]) {
-            return;
+            return null;
         }
 
         $delimiter = $this->pattern[0];

src/Symfony/Component/VarDumper/Cloner/Data.php

@@ -223,7 +223,7 @@ class Data implements \ArrayAccess, \Countable, \IteratorAggregate
             $item = $item->value;
         }
         if (!($item = $this->getStub($item)) instanceof Stub || !$item->position) {
-            return;
+            return null;
         }
         $keys = [$key];
 
@@ -238,7 +238,7 @@ class Data implements \ArrayAccess, \Countable, \IteratorAggregate
             case Stub::TYPE_RESOURCE:
                 break;
             default:
-                return;
+                return null;
         }
 
         $data = null;