diff --git a/CHANGELOG-2.7.md b/CHANGELOG-2.7.md
index cf90bc2e50f34..f5471bf653f4b 100644
--- a/CHANGELOG-2.7.md
+++ b/CHANGELOG-2.7.md
@@ -7,6 +7,10 @@ in 2.7 minor versions.
 To get the diff for a specific change, go to https://github.com/symfony/symfony/commit/XXX where XXX is the change hash
 To get the diff between two versions, go to https://github.com/symfony/symfony/compare/v2.7.0...v2.7.1
 
+* 2.7.31 (2017-07-05)
+
+ * bug #23378 [FrameworkBundle] Do not remove files from assets dir (1ed)
+
 * 2.7.30 (2017-07-03)
 
  * bug #23341 [DoctrineBridge][Security][Validator] do not validate empty values (xabbuh)
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index 0b695308c528f..3e670f8d67e90 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -70,9 +70,9 @@ Symfony is the result of the work of many people who made the code better
  - Deni
  - Henrik Westphal (snc)
  - Dariusz Górecki (canni)
+ - Jáchym Toušek (enumag)
  - Titouan Galopin (tgalopin)
  - Douglas Greenshields (shieldo)
- - Jáchym Toušek (enumag)
  - Konstantin Myakshin (koc)
  - Lee McDermott
  - Brandon Turner
@@ -99,11 +99,12 @@ Symfony is the result of the work of many people who made the code better
  - Baptiste Clavié (talus)
  - Vladimir Reznichenko (kalessil)
  - marc.weistroff
+ - Yonel Ceruto González (yonelceruto)
  - lenar
  - Włodzimierz Gajda (gajdaw)
- - Yonel Ceruto González (yonelceruto)
  - Alexander Schwenn (xelaris)
  - Jacob Dreesen (jdreesen)
+ - Tobias Nyholm (tobias)
  - Florian Voutzinos (florianv)
  - Colin Frei
  - Adrien Brault (adrienbrault)
@@ -111,7 +112,6 @@ Symfony is the result of the work of many people who made the code better
  - Peter Kokot (maastermedia)
  - David Buchmann (dbu)
  - excelwebzone
- - Tobias Nyholm (tobias)
  - Tomáš Votruba (tomas_votruba)
  - Fabien Pennequin (fabienpennequin)
  - Gordon Franke (gimler)
@@ -133,12 +133,15 @@ Symfony is the result of the work of many people who made the code better
  - Guilherme Blanco (guilhermeblanco)
  - Pablo Godel (pgodel)
  - Jérémie Augustin (jaugustin)
+ - Dany Maillard (maidmaid)
  - Andréia Bohner (andreia)
  - Rafael Dohms (rdohms)
  - Arnaud Kleinpeter (nanocom)
  - jwdeitch
+ - David Maicher (dmaicher)
  - Mikael Pajunen
  - Joel Wurtz (brouznouf)
+ - Grégoire Paris (greg0ire)
  - Philipp Wahala (hifi)
  - Vyacheslav Pavlov
  - Richard van Laak (rvanlaak)
@@ -147,11 +150,9 @@ Symfony is the result of the work of many people who made the code better
  - Thomas Rabaix (rande)
  - Rouven Weßling (realityking)
  - Teoh Han Hui (teohhanhui)
- - David Maicher (dmaicher)
  - Jérôme Vasseur (jvasseur)
  - Clemens Tolboom
  - Helmer Aaviksoo
- - Grégoire Paris (greg0ire)
  - Hiromi Hishida (77web)
  - Matthieu Ouellette-Vachon (maoueh)
  - Michał Pipa (michal.pipa)
@@ -234,7 +235,6 @@ Symfony is the result of the work of many people who made the code better
  - Arjen Brouwer (arjenjb)
  - Katsuhiro OGAWA
  - Patrick McDougle (patrick-mcdougle)
- - Dany Maillard (maidmaid)
  - Alif Rachmawadi
  - Kristen Gilden (kgilden)
  - Pierre-Yves LEBECQ (pylebecq)
@@ -620,6 +620,7 @@ Symfony is the result of the work of many people who made the code better
  - develop
  - ReenExe
  - Mark Sonnabaum
+ - Maxime Veber (nek-)
  - Richard Quadling
  - jochenvdv
  - Arturas Smorgun (asarturas)
@@ -642,6 +643,7 @@ Symfony is the result of the work of many people who made the code better
  - Trent Steel (trsteel88)
  - Yuen-Chi Lian
  - Besnik Br
+ - Jose Gonzalez
  - Dariusz Ruminski
  - Joshua Nye
  - Claudio Zizza
@@ -1081,7 +1083,6 @@ Symfony is the result of the work of many people who made the code better
  - Max Summe
  - WedgeSama
  - Felds Liscia
- - Maxime Veber (nek-)
  - Sullivan SENECHAL
  - Tadcka
  - Beth Binkovitz
@@ -1092,12 +1093,12 @@ Symfony is the result of the work of many people who made the code better
  - Tomaz Ahlin
  - Marcus Stöhr (dafish)
  - Emmanuel Vella (emmanuel.vella)
+ - Adam Szaraniec (mimol)
  - Carsten Nielsen (phreaknerd)
  - Mathieu Rochette
  - Jay Severson
  - René Kerner
  - Nathaniel Catchpole
- - Jose Gonzalez
  - Adrien Samson (adriensamson)
  - Samuel Gordalina (gordalina)
  - Max Romanovsky (maxromanovsky)
@@ -1258,6 +1259,7 @@ Symfony is the result of the work of many people who made the code better
  - Aarón Nieves Fernández
  - Mike Meier
  - Kirill Saksin
+ - Julien Pauli
  - Koalabaerchen
  - michalmarcinkowski
  - Warwick
@@ -1305,6 +1307,7 @@ Symfony is the result of the work of many people who made the code better
  - klemens
  - dened
  - Dmitry Korotovsky
+ - mcorteel
  - Michael van Tricht
  - Sam Ward
  - Walther Lalk
@@ -1335,6 +1338,7 @@ Symfony is the result of the work of many people who made the code better
  - Jan Marek (janmarek)
  - Mark de Haan (markdehaan)
  - Dan Patrick (mdpatrick)
+ - Pedro Magalhães (pmmaga)
  - Rares Vlaseanu (raresvla)
  - tante kinast (tante)
  - Vincent LEFORT (vlefort)
@@ -1542,6 +1546,7 @@ Symfony is the result of the work of many people who made the code better
  - Abdulkadir N. A.
  - Yevgen Kovalienia
  - Lebnik
+ - Shude
  - Ondřej Führer
  - Sema
  - Elan Ruusamäe
diff --git a/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php b/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php
index 0a3ea2871deb3..27cccd869e9a0 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php
@@ -92,7 +92,9 @@ protected function execute(InputInterface $input, OutputInterface $output)
         $validAssetDirs = array();
         foreach ($this->getContainer()->get('kernel')->getBundles() as $bundle) {
             if (is_dir($originDir = $bundle->getPath().'/Resources/public')) {
-                $targetDir = $bundlesDir.preg_replace('/bundle$/', '', strtolower($bundle->getName()));
+                $assetDir = preg_replace('/bundle$/', '', strtolower($bundle->getName()));
+                $targetDir = $bundlesDir.$assetDir;
+                $validAssetDirs[] = $assetDir;
 
                 $output->writeln(sprintf('Installing assets for <comment>%s</comment> into <comment>%s</comment>', $bundle->getNamespace(), $targetDir));
 
@@ -132,15 +134,12 @@ protected function execute(InputInterface $input, OutputInterface $output)
                 } else {
                     $this->hardCopy($originDir, $targetDir);
                 }
-                $validAssetDirs[] = $targetDir;
             }
         }
+
         // remove the assets of the bundles that no longer exist
-        foreach (new \FilesystemIterator($bundlesDir) as $dir) {
-            if (!in_array($dir, $validAssetDirs)) {
-                $filesystem->remove($dir);
-            }
-        }
+        $dirsToRemove = Finder::create()->depth(0)->directories()->exclude($validAssetDirs)->in($bundlesDir);
+        $filesystem->remove($dirsToRemove);
     }
 
     /**
diff --git a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/SecurityRoutingIntegrationTest.php b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/SecurityRoutingIntegrationTest.php
index 3abfd9585f159..5996415e10a64 100644
--- a/src/Symfony/Bundle/SecurityBundle/Tests/Functional/SecurityRoutingIntegrationTest.php
+++ b/src/Symfony/Bundle/SecurityBundle/Tests/Functional/SecurityRoutingIntegrationTest.php
@@ -78,27 +78,27 @@ public function testSecurityConfigurationForMultipleIPAddresses($config)
         $this->assertRestricted($barredClient, '/secured-by-two-ips');
     }
 
-   /**
-    * @dataProvider getConfigs
-    */
-   public function testSecurityConfigurationForExpression($config)
-   {
-       $allowedClient = $this->createClient(array('test_case' => 'StandardFormLogin', 'root_config' => $config), array('HTTP_USER_AGENT' => 'Firefox 1.0'));
-       $this->assertAllowed($allowedClient, '/protected-via-expression');
-
-       $barredClient = $this->createClient(array('test_case' => 'StandardFormLogin', 'root_config' => $config), array());
-       $this->assertRestricted($barredClient, '/protected-via-expression');
-
-       $allowedClient = $this->createClient(array('test_case' => 'StandardFormLogin', 'root_config' => $config), array());
-
-       $allowedClient->request('GET', '/protected-via-expression');
-       $form = $allowedClient->followRedirect()->selectButton('login')->form();
-       $form['_username'] = 'johannes';
-       $form['_password'] = 'test';
-       $allowedClient->submit($form);
-       $this->assertRedirect($allowedClient->getResponse(), '/protected-via-expression');
-       $this->assertAllowed($allowedClient, '/protected-via-expression');
-   }
+    /**
+     * @dataProvider getConfigs
+     */
+    public function testSecurityConfigurationForExpression($config)
+    {
+        $allowedClient = $this->createClient(array('test_case' => 'StandardFormLogin', 'root_config' => $config), array('HTTP_USER_AGENT' => 'Firefox 1.0'));
+        $this->assertAllowed($allowedClient, '/protected-via-expression');
+
+        $barredClient = $this->createClient(array('test_case' => 'StandardFormLogin', 'root_config' => $config), array());
+        $this->assertRestricted($barredClient, '/protected-via-expression');
+
+        $allowedClient = $this->createClient(array('test_case' => 'StandardFormLogin', 'root_config' => $config), array());
+
+        $allowedClient->request('GET', '/protected-via-expression');
+        $form = $allowedClient->followRedirect()->selectButton('login')->form();
+        $form['_username'] = 'johannes';
+        $form['_password'] = 'test';
+        $allowedClient->submit($form);
+        $this->assertRedirect($allowedClient->getResponse(), '/protected-via-expression');
+        $this->assertAllowed($allowedClient, '/protected-via-expression');
+    }
 
     private function assertAllowed($client, $path)
     {
diff --git a/src/Symfony/Component/ClassLoader/Tests/LegacyApcUniversalClassLoaderTest.php b/src/Symfony/Component/ClassLoader/Tests/LegacyApcUniversalClassLoaderTest.php
index 6d4e57e984504..8ef97bfd58822 100644
--- a/src/Symfony/Component/ClassLoader/Tests/LegacyApcUniversalClassLoaderTest.php
+++ b/src/Symfony/Component/ClassLoader/Tests/LegacyApcUniversalClassLoaderTest.php
@@ -43,17 +43,17 @@ public function testConstructor()
         $this->assertEquals($loader->findFile('\LegacyApc\Namespaced\FooBar'), apcu_fetch('test.prefix.\LegacyApc\Namespaced\FooBar'), '__construct() takes a prefix as its first argument');
     }
 
-   /**
-    * @dataProvider getLoadClassTests
-    */
-   public function testLoadClass($className, $testClassName, $message)
-   {
-       $loader = new ApcUniversalClassLoader('test.prefix.');
-       $loader->registerNamespace('LegacyApc\Namespaced', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
-       $loader->registerPrefix('LegacyApc_Pearlike_', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
-       $loader->loadClass($testClassName);
-       $this->assertTrue(class_exists($className), $message);
-   }
+    /**
+     * @dataProvider getLoadClassTests
+     */
+    public function testLoadClass($className, $testClassName, $message)
+    {
+        $loader = new ApcUniversalClassLoader('test.prefix.');
+        $loader->registerNamespace('LegacyApc\Namespaced', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->registerPrefix('LegacyApc_Pearlike_', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->loadClass($testClassName);
+        $this->assertTrue(class_exists($className), $message);
+    }
 
     public function getLoadClassTests()
     {
@@ -63,19 +63,19 @@ public function getLoadClassTests()
        );
     }
 
-   /**
-    * @dataProvider getLoadClassFromFallbackTests
-    */
-   public function testLoadClassFromFallback($className, $testClassName, $message)
-   {
-       $loader = new ApcUniversalClassLoader('test.prefix.fallback');
-       $loader->registerNamespace('LegacyApc\Namespaced', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
-       $loader->registerPrefix('LegacyApc_Pearlike_', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
-       $loader->registerNamespaceFallbacks(array(__DIR__.DIRECTORY_SEPARATOR.'Fixtures/LegacyApc/fallback'));
-       $loader->registerPrefixFallbacks(array(__DIR__.DIRECTORY_SEPARATOR.'Fixtures/LegacyApc/fallback'));
-       $loader->loadClass($testClassName);
-       $this->assertTrue(class_exists($className), $message);
-   }
+    /**
+     * @dataProvider getLoadClassFromFallbackTests
+     */
+    public function testLoadClassFromFallback($className, $testClassName, $message)
+    {
+        $loader = new ApcUniversalClassLoader('test.prefix.fallback');
+        $loader->registerNamespace('LegacyApc\Namespaced', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->registerPrefix('LegacyApc_Pearlike_', __DIR__.DIRECTORY_SEPARATOR.'Fixtures');
+        $loader->registerNamespaceFallbacks(array(__DIR__.DIRECTORY_SEPARATOR.'Fixtures/LegacyApc/fallback'));
+        $loader->registerPrefixFallbacks(array(__DIR__.DIRECTORY_SEPARATOR.'Fixtures/LegacyApc/fallback'));
+        $loader->loadClass($testClassName);
+        $this->assertTrue(class_exists($className), $message);
+    }
 
     public function getLoadClassFromFallbackTests()
     {
@@ -87,18 +87,18 @@ public function getLoadClassFromFallbackTests()
        );
     }
 
-   /**
-    * @dataProvider getLoadClassNamespaceCollisionTests
-    */
-   public function testLoadClassNamespaceCollision($namespaces, $className, $message)
-   {
-       $loader = new ApcUniversalClassLoader('test.prefix.collision.');
-       $loader->registerNamespaces($namespaces);
+    /**
+     * @dataProvider getLoadClassNamespaceCollisionTests
+     */
+    public function testLoadClassNamespaceCollision($namespaces, $className, $message)
+    {
+        $loader = new ApcUniversalClassLoader('test.prefix.collision.');
+        $loader->registerNamespaces($namespaces);
 
-       $loader->loadClass($className);
+        $loader->loadClass($className);
 
-       $this->assertTrue(class_exists($className), $message);
-   }
+        $this->assertTrue(class_exists($className), $message);
+    }
 
     public function getLoadClassNamespaceCollisionTests()
     {
@@ -138,17 +138,17 @@ public function getLoadClassNamespaceCollisionTests()
        );
     }
 
-   /**
-    * @dataProvider getLoadClassPrefixCollisionTests
-    */
-   public function testLoadClassPrefixCollision($prefixes, $className, $message)
-   {
-       $loader = new ApcUniversalClassLoader('test.prefix.collision.');
-       $loader->registerPrefixes($prefixes);
-
-       $loader->loadClass($className);
-       $this->assertTrue(class_exists($className), $message);
-   }
+    /**
+     * @dataProvider getLoadClassPrefixCollisionTests
+     */
+    public function testLoadClassPrefixCollision($prefixes, $className, $message)
+    {
+        $loader = new ApcUniversalClassLoader('test.prefix.collision.');
+        $loader->registerPrefixes($prefixes);
+
+        $loader->loadClass($className);
+        $this->assertTrue(class_exists($className), $message);
+    }
 
     public function getLoadClassPrefixCollisionTests()
     {
diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index 93be7003c1b37..6233186a48e22 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -58,11 +58,11 @@ abstract class Kernel implements KernelInterface, TerminableInterface
     protected $startTime;
     protected $loadClassCache;
 
-    const VERSION = '2.7.30';
-    const VERSION_ID = 20730;
+    const VERSION = '2.7.31';
+    const VERSION_ID = 20731;
     const MAJOR_VERSION = 2;
     const MINOR_VERSION = 7;
-    const RELEASE_VERSION = 30;
+    const RELEASE_VERSION = 31;
     const EXTRA_VERSION = '';
 
     const END_OF_MAINTENANCE = '05/2018';