diff --git a/.php_cs.dist b/.php_cs.dist
index 9b8d082116..a9919c636f 100644
--- a/.php_cs.dist
+++ b/.php_cs.dist
@@ -8,9 +8,10 @@ return PhpCsFixer\Config::create()
     ->setRules(array(
         '@Symfony' => true,
         '@Symfony:risky' => true,
+        '@PHPUnit48Migration:risky' => true,
+        'php_unit_no_expectation_annotation' => false, // part of `PHPUnitXYMigration:risky` ruleset, to be enabled when PHPUnit 4.x support will be dropped, as we don't want to rewrite exceptions handling twice
         'array_syntax' => array('syntax' => 'long'),
         'protected_to_private' => false,
-        'php_unit_dedicate_assert' => array('target' => '3.5'),
     ))
     ->setRiskyAllowed(true)
     ->setFinder(
diff --git a/src/Symfony/Bridge/PhpUnit/composer.json b/src/Symfony/Bridge/PhpUnit/composer.json
index 47f6d7b5e8..24a48b600d 100644
--- a/src/Symfony/Bridge/PhpUnit/composer.json
+++ b/src/Symfony/Bridge/PhpUnit/composer.json
@@ -41,6 +41,10 @@
     "extra": {
         "branch-alias": {
             "dev-master": "3.4-dev"
+        },
+        "thanks": {
+            "name": "phpunit/phpunit",
+            "url": "https://github.com/sebastianbergmann/phpunit"
         }
     }
 }
diff --git a/src/Symfony/Bundle/WebServerBundle/Resources/router.php b/src/Symfony/Bundle/WebServerBundle/Resources/router.php
index 187be0b836..a366b381aa 100644
--- a/src/Symfony/Bundle/WebServerBundle/Resources/router.php
+++ b/src/Symfony/Bundle/WebServerBundle/Resources/router.php
@@ -30,7 +30,7 @@ if (is_file($_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.$_SERVER['SCRIPT_NAME'
     return false;
 }
 
-$script = getenv('APP_FRONT_CONTROLLER') ?: 'index.php';
+$script = isset($_ENV['APP_FRONT_CONTROLLER']) ? $_ENV['APP_FRONT_CONTROLLER'] : 'index.php';
 
 $_SERVER = array_merge($_SERVER, $_ENV);
 $_SERVER['SCRIPT_FILENAME'] = $_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.$script;
diff --git a/src/Symfony/Bundle/WebServerBundle/WebServer.php b/src/Symfony/Bundle/WebServerBundle/WebServer.php
index e3425ec8bb..beb5190b72 100644
--- a/src/Symfony/Bundle/WebServerBundle/WebServer.php
+++ b/src/Symfony/Bundle/WebServerBundle/WebServer.php
@@ -146,11 +146,11 @@ class WebServer
     private function createServerProcess(WebServerConfig $config)
     {
         $finder = new PhpExecutableFinder();
-        if (false === $binary = $finder->find()) {
+        if (false === $binary = $finder->find(false)) {
             throw new \RuntimeException('Unable to find the PHP binary.');
         }
 
-        $process = new Process(array($binary, '-S', $config->getAddress(), $config->getRouter()));
+        $process = new Process(array_merge(array($binary), $finder->findArguments(), array('-dvariables_order=EGPCS', '-S', $config->getAddress(), $config->getRouter())));
         $process->setWorkingDirectory($config->getDocumentRoot());
         $process->setTimeout(null);
 
diff --git a/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php b/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php
index 6c17d110fe..8b88eaecad 100644
--- a/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php
+++ b/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php
@@ -32,7 +32,7 @@ class WebServerConfig
             throw new \InvalidArgumentException(sprintf('Unable to find the front controller under "%s" (none of these files exist: %s).', $documentRoot, implode(', ', $this->getFrontControllerFileNames($env))));
         }
 
-        putenv('APP_FRONT_CONTROLLER='.$file);
+        $_ENV['APP_FRONT_CONTROLLER'] = $file;
 
         $this->documentRoot = $documentRoot;
         $this->env = $env;
diff --git a/src/Symfony/Bundle/WebServerBundle/composer.json b/src/Symfony/Bundle/WebServerBundle/composer.json
index f51be62350..87272bba7b 100644
--- a/src/Symfony/Bundle/WebServerBundle/composer.json
+++ b/src/Symfony/Bundle/WebServerBundle/composer.json
@@ -21,7 +21,7 @@
         "symfony/console": "~3.4|~4.0",
         "symfony/dependency-injection": "~3.4|~4.0",
         "symfony/http-kernel": "~3.3|~4.0",
-        "symfony/process": "~3.3|~4.0"
+        "symfony/process": "~3.3.14|^3.4.2|^4.0.2"
     },
     "autoload": {
         "psr-4": { "Symfony\\Bundle\\WebServerBundle\\": "" },
diff --git a/src/Symfony/Component/Cache/Traits/MemcachedTrait.php b/src/Symfony/Component/Cache/Traits/MemcachedTrait.php
index 82344fceae..9b877efb08 100644
--- a/src/Symfony/Component/Cache/Traits/MemcachedTrait.php
+++ b/src/Symfony/Component/Cache/Traits/MemcachedTrait.php
@@ -71,7 +71,7 @@ trait MemcachedTrait
      *
      * @return \Memcached
      *
-     * @throws \ErrorEception When invalid options or servers are provided
+     * @throws \ErrorException When invalid options or servers are provided
      */
     public static function createConnection($servers, array $options = array())
     {
diff --git a/src/Symfony/Component/Config/Definition/Builder/ExprBuilder.php b/src/Symfony/Component/Config/Definition/Builder/ExprBuilder.php
index 3ea97802dc..64c0f5578a 100644
--- a/src/Symfony/Component/Config/Definition/Builder/ExprBuilder.php
+++ b/src/Symfony/Component/Config/Definition/Builder/ExprBuilder.php
@@ -186,7 +186,7 @@ class ExprBuilder
      */
     public function thenInvalid($message)
     {
-        $this->thenPart = function ($v) use ($message) {throw new \InvalidArgumentException(sprintf($message, json_encode($v))); };
+        $this->thenPart = function ($v) use ($message) { throw new \InvalidArgumentException(sprintf($message, json_encode($v))); };
 
         return $this;
     }
diff --git a/src/Symfony/Component/Config/ResourceCheckerConfigCache.php b/src/Symfony/Component/Config/ResourceCheckerConfigCache.php
index 10257d5dd4..0a79b84c1c 100644
--- a/src/Symfony/Component/Config/ResourceCheckerConfigCache.php
+++ b/src/Symfony/Component/Config/ResourceCheckerConfigCache.php
@@ -158,7 +158,7 @@ class ResourceCheckerConfigCache implements ConfigCacheInterface
         $meta = false;
         $signalingException = new \UnexpectedValueException();
         $prevUnserializeHandler = ini_set('unserialize_callback_func', '');
-        $prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context) use (&$prevErrorHandler, $signalingException) {
+        $prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context = array()) use (&$prevErrorHandler, $signalingException) {
             if (E_WARNING === $type && 'Class __PHP_Incomplete_Class has no unserializer' === $msg) {
                 throw $signalingException;
             }
diff --git a/src/Symfony/Component/Console/Application.php b/src/Symfony/Component/Console/Application.php
index f3bc0d5964..be283aad16 100644
--- a/src/Symfony/Component/Console/Application.php
+++ b/src/Symfony/Component/Console/Application.php
@@ -580,6 +580,7 @@ class Application
     {
         $this->init();
 
+        $aliases = array();
         $allCommands = $this->commandLoader ? array_merge($this->commandLoader->getNames(), array_keys($this->commands)) : array_keys($this->commands);
         $expr = preg_replace_callback('{([^:]+|)}', function ($matches) { return preg_quote($matches[1]).'[^:]*'; }, $name);
         $commands = preg_grep('{^'.$expr.'}', $allCommands);
@@ -612,14 +613,15 @@ class Application
         // filter out aliases for commands which are already on the list
         if (count($commands) > 1) {
             $commandList = $this->commandLoader ? array_merge(array_flip($this->commandLoader->getNames()), $this->commands) : $this->commands;
-            $commands = array_unique(array_filter($commands, function ($nameOrAlias) use ($commandList, $commands) {
+            $commands = array_unique(array_filter($commands, function ($nameOrAlias) use ($commandList, $commands, &$aliases) {
                 $commandName = $commandList[$nameOrAlias] instanceof Command ? $commandList[$nameOrAlias]->getName() : $nameOrAlias;
+                $aliases[$nameOrAlias] = $commandName;
 
                 return $commandName === $nameOrAlias || !in_array($commandName, $commands);
             }));
         }
 
-        $exact = in_array($name, $commands, true);
+        $exact = in_array($name, $commands, true) || isset($aliases[$name]);
         if (count($commands) > 1 && !$exact) {
             $usableWidth = $this->terminal->getWidth() - 10;
             $abbrevs = array_values($commands);
diff --git a/src/Symfony/Component/Console/Tests/ApplicationTest.php b/src/Symfony/Component/Console/Tests/ApplicationTest.php
index 4e1f8811b2..f207ce0d4f 100644
--- a/src/Symfony/Component/Console/Tests/ApplicationTest.php
+++ b/src/Symfony/Component/Console/Tests/ApplicationTest.php
@@ -57,6 +57,8 @@ class ApplicationTest extends TestCase
         require_once self::$fixturesPath.'/BarBucCommand.php';
         require_once self::$fixturesPath.'/FooSubnamespaced1Command.php';
         require_once self::$fixturesPath.'/FooSubnamespaced2Command.php';
+        require_once self::$fixturesPath.'/TestTiti.php';
+        require_once self::$fixturesPath.'/TestToto.php';
     }
 
     protected function normalizeLineBreaks($text)
@@ -283,6 +285,14 @@ class ApplicationTest extends TestCase
         $application->findNamespace('f');
     }
 
+    public function testFindNonAmbiguous()
+    {
+        $application = new Application();
+        $application->add(new \TestTiti());
+        $application->add(new \TestToto());
+        $this->assertEquals('test-toto', $application->find('test')->getName());
+    }
+
     /**
      * @expectedException        \Symfony\Component\Console\Exception\CommandNotFoundException
      * @expectedExceptionMessage There are no commands defined in the "bar" namespace.
diff --git a/src/Symfony/Component/Console/Tests/Fixtures/TestTiti.php b/src/Symfony/Component/Console/Tests/Fixtures/TestTiti.php
new file mode 100644
index 0000000000..72e29d2a0a
--- /dev/null
+++ b/src/Symfony/Component/Console/Tests/Fixtures/TestTiti.php
@@ -0,0 +1,21 @@
+<?php
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class TestTiti extends Command
+{
+    protected function configure()
+    {
+        $this
+            ->setName('test-titi')
+            ->setDescription('The test:titi command')
+        ;
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output)
+    {
+        $output->write('test-titi');
+    }
+}
diff --git a/src/Symfony/Component/Console/Tests/Fixtures/TestToto.php b/src/Symfony/Component/Console/Tests/Fixtures/TestToto.php
new file mode 100644
index 0000000000..f14805db68
--- /dev/null
+++ b/src/Symfony/Component/Console/Tests/Fixtures/TestToto.php
@@ -0,0 +1,22 @@
+<?php
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class TestToto extends Command
+{
+    protected function configure()
+    {
+        $this
+            ->setName('test-toto')
+            ->setDescription('The test-toto command')
+            ->setAliases(array('test'))
+        ;
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output)
+    {
+        $output->write('test-toto');
+    }
+}
diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index 98f414783f..b8ac23bc84 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -1990,6 +1990,7 @@ class Request
             'js' => array('application/javascript', 'application/x-javascript', 'text/javascript'),
             'css' => array('text/css'),
             'json' => array('application/json', 'application/x-json'),
+            'jsonld' => array('application/ld+json'),
             'xml' => array('text/xml', 'application/xml', 'application/x-xml'),
             'rdf' => array('application/rdf+xml'),
             'atom' => array('application/atom+xml'),
diff --git a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
index 3c4a13acf4..178c729001 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
@@ -372,6 +372,7 @@ class RequestTest extends TestCase
             array('js', array('application/javascript', 'application/x-javascript', 'text/javascript')),
             array('css', array('text/css')),
             array('json', array('application/json', 'application/x-json')),
+            array('jsonld', array('application/ld+json')),
             array('xml', array('text/xml', 'application/xml', 'application/x-xml')),
             array('rdf', array('application/rdf+xml')),
             array('atom', array('application/atom+xml')),
@@ -968,6 +969,26 @@ class RequestTest extends TestCase
         $request->getClientIps();
     }
 
+    /**
+     * @dataProvider getClientIpsWithConflictingHeadersProvider
+     */
+    public function testGetClientIpsOnlyXHttpForwardedForTrusted($httpForwarded, $httpXForwardedFor)
+    {
+        $request = new Request();
+
+        $server = array(
+            'REMOTE_ADDR' => '88.88.88.88',
+            'HTTP_FORWARDED' => $httpForwarded,
+            'HTTP_X_FORWARDED_FOR' => $httpXForwardedFor,
+        );
+
+        Request::setTrustedProxies(array('88.88.88.88'), Request::HEADER_X_FORWARDED_FOR);
+
+        $request->initialize(array(), array(), array(), array(), array(), $server);
+
+        $this->assertSame(array_reverse(explode(',', $httpXForwardedFor)), $request->getClientIps());
+    }
+
     public function getClientIpsWithConflictingHeadersProvider()
     {
         //        $httpForwarded                   $httpXForwardedFor
diff --git a/src/Symfony/Component/Process/Process.php b/src/Symfony/Component/Process/Process.php
index 22af36e7c4..08963bcbaa 100644
--- a/src/Symfony/Component/Process/Process.php
+++ b/src/Symfony/Component/Process/Process.php
@@ -326,12 +326,20 @@ class Process implements \IteratorAggregate
             // @see : https://bugs.php.net/69442
             $ptsWorkaround = fopen(__FILE__, 'r');
         }
+        if (defined('HHVM_VERSION')) {
+            $envPairs = $env;
+        } else {
+            $envPairs = array();
+            foreach ($env as $k => $v) {
+                $envPairs[] = $k.'='.$v;
+            }
+        }
 
         if (!is_dir($this->cwd)) {
             @trigger_error('The provided cwd does not exist. Command is currently ran against getcwd(). This behavior is deprecated since version 3.4 and will be removed in 4.0.', E_USER_DEPRECATED);
         }
 
-        $this->process = proc_open($commandline, $descriptors, $this->processPipes->pipes, $this->cwd, $env, $this->options);
+        $this->process = proc_open($commandline, $descriptors, $this->processPipes->pipes, $this->cwd, $envPairs, $this->options);
 
         if (!is_resource($this->process)) {
             throw new RuntimeException('Unable to launch a new process.');
@@ -1722,15 +1730,11 @@ class Process implements \IteratorAggregate
 
     private function getDefaultEnv()
     {
-        if (\PHP_VERSION_ID >= 70100) {
-            $env = getenv();
-        } else {
-            $env = array();
+        $env = array();
 
-            foreach ($_SERVER as $k => $v) {
-                if (is_string($v) && false !== $v = getenv($k)) {
-                    $env[$k] = $v;
-                }
+        foreach ($_SERVER as $k => $v) {
+            if (is_string($v) && false !== $v = getenv($k)) {
+                $env[$k] = $v;
             }
         }
 
diff --git a/src/Symfony/Component/Process/Tests/ProcessTest.php b/src/Symfony/Component/Process/Tests/ProcessTest.php
index 914959b58c..fccf0dc0f3 100644
--- a/src/Symfony/Component/Process/Tests/ProcessTest.php
+++ b/src/Symfony/Component/Process/Tests/ProcessTest.php
@@ -1441,14 +1441,14 @@ class ProcessTest extends TestCase
 
     public function testEnvIsInherited()
     {
-        $process = $this->getProcessForCode('echo serialize($_SERVER);', null, array('BAR' => 'BAZ'));
+        $process = $this->getProcessForCode('echo serialize($_SERVER);', null, array('BAR' => 'BAZ', 'EMPTY' => ''));
 
         putenv('FOO=BAR');
         $_ENV['FOO'] = 'BAR';
 
         $process->run();
 
-        $expected = array('BAR' => 'BAZ', 'FOO' => 'BAR');
+        $expected = array('BAR' => 'BAZ', 'EMPTY' => '', 'FOO' => 'BAR');
         $env = array_intersect_key(unserialize($process->getOutput()), $expected);
 
         $this->assertEquals($expected, $env);
diff --git a/src/Symfony/Component/PropertyAccess/PropertyAccessor.php b/src/Symfony/Component/PropertyAccess/PropertyAccessor.php
index c23229dd86..d0db3946e4 100644
--- a/src/Symfony/Component/PropertyAccess/PropertyAccessor.php
+++ b/src/Symfony/Component/PropertyAccess/PropertyAccessor.php
@@ -245,7 +245,7 @@ class PropertyAccessor implements PropertyAccessorInterface
     /**
      * @internal
      */
-    public static function handleError($type, $message, $file, $line, $context)
+    public static function handleError($type, $message, $file, $line, $context = array())
     {
         if (E_RECOVERABLE_ERROR === $type) {
             self::throwInvalidArgumentException($message, debug_backtrace(false), 1);
diff --git a/src/Symfony/Component/Serializer/Normalizer/CustomNormalizer.php b/src/Symfony/Component/Serializer/Normalizer/CustomNormalizer.php
index b56b10f2dc..6a15d8da90 100644
--- a/src/Symfony/Component/Serializer/Normalizer/CustomNormalizer.php
+++ b/src/Symfony/Component/Serializer/Normalizer/CustomNormalizer.php
@@ -57,7 +57,7 @@ class CustomNormalizer implements NormalizerInterface, DenormalizerInterface, Se
     }
 
     /**
-     * Checks if the given class implements the NormalizableInterface.
+     * Checks if the given class implements the DenormalizableInterface.
      *
      * @param mixed  $data   Data to denormalize from
      * @param string $type   The class to which the data should be denormalized
diff --git a/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php b/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php
index 5e0a0b1531..e324692700 100644
--- a/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php
+++ b/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php
@@ -212,7 +212,7 @@ abstract class AbstractCloner implements ClonerInterface
      */
     public function cloneVar($var, $filter = 0)
     {
-        $this->prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context) {
+        $this->prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context = array()) {
             if (E_RECOVERABLE_ERROR === $type || E_USER_ERROR === $type) {
                 // Cloner never dies
                 throw new \ErrorException($msg, 0, $type, $file, $line);