diff --git a/src/Symfony/Bridge/Twig/README.md b/src/Symfony/Bridge/Twig/README.md
index eb084147c3..602f5a54c3 100644
--- a/src/Symfony/Bridge/Twig/README.md
+++ b/src/Symfony/Bridge/Twig/README.md
@@ -1,7 +1,7 @@
 Twig Bridge
 ===========
 
-Provides integration for [Twig](http://twig.sensiolabs.org/) with various
+Provides integration for [Twig](https://twig.symfony.com/) with various
 Symfony components.
 
 Resources
diff --git a/src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php b/src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php
index 5e06d54a0a..92a0c075af 100644
--- a/src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php
+++ b/src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php
@@ -421,6 +421,7 @@ class ChoiceType extends AbstractType
             // See https://github.com/symfony/symfony/pull/5582
             'data_class' => null,
             'choice_translation_domain' => true,
+            'trim' => false,
         ));
 
         $resolver->setNormalizer('choices', $choicesNormalizer);
diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php
index cca7397250..2c4c15f410 100644
--- a/src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php
+++ b/src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php
@@ -2567,4 +2567,59 @@ class ChoiceTypeTest extends BaseTypeTest
         $this->assertEquals('_09name', $view->vars['name']);
         $this->assertEquals('_09name', $view->vars['full_name']);
     }
+
+        /**
+     * @dataProvider provideTrimCases
+     */
+    public function testTrimIsDisabled($multiple, $expanded)
+    {
+        $form = $this->factory->create(static::TESTED_TYPE, null, array(
+            'multiple' => $multiple,
+            'expanded' => $expanded,
+            'choices' => array(
+                'a' => '1',
+            ),
+            'choices_as_values' => true,
+        ));
+
+        $submittedData = ' 1';
+
+        $form->submit($multiple ? (array) $submittedData : $submittedData);
+
+        // When the choice does not exist the transformation fails
+        $this->assertFalse($form->isSynchronized());
+        $this->assertNull($form->getData());
+    }
+
+    /**
+     * @dataProvider provideTrimCases
+     */
+    public function testSubmitValueWithWhiteSpace($multiple, $expanded)
+    {
+        $valueWhitWhiteSpace = '1 ';
+
+        $form = $this->factory->create(static::TESTED_TYPE, null, array(
+            'multiple' => $multiple,
+            'expanded' => $expanded,
+            'choices' => array(
+                'a' => $valueWhitWhiteSpace,
+            ),
+            'choices_as_values' => true,
+        ));
+
+        $form->submit($multiple ? (array) $valueWhitWhiteSpace : $valueWhitWhiteSpace);
+
+        $this->assertTrue($form->isSynchronized());
+        $this->assertSame($multiple ? (array) $valueWhitWhiteSpace : $valueWhitWhiteSpace, $form->getData());
+    }
+
+    public function provideTrimCases()
+    {
+        return array(
+            'Simple' => array(false, false),
+            'Multiple' => array(true, false),
+            'Simple expanded' => array(false, true),
+            'Multiple expanded' => array(true, true),
+        );
+    }
 }
diff --git a/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php b/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php
index c2ac6768c3..3c35810465 100644
--- a/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php
+++ b/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php
@@ -43,7 +43,21 @@ class FileBinaryMimeTypeGuesser implements MimeTypeGuesserInterface
      */
     public static function isSupported()
     {
-        return '\\' !== DIRECTORY_SEPARATOR && function_exists('passthru') && function_exists('escapeshellarg');
+        static $supported = null;
+
+        if (null !== $supported) {
+            return $supported;
+        }
+
+        if ('\\' === DIRECTORY_SEPARATOR || !function_exists('passthru') || !function_exists('escapeshellarg')) {
+            return $supported = false;
+        }
+
+        ob_start();
+        passthru('command -v file', $exitStatus);
+        $binPath = trim(ob_get_clean());
+
+        return $supported = 0 === $exitStatus && '' !== $binPath;
     }
 
     /**
diff --git a/src/Symfony/Component/HttpFoundation/Response.php b/src/Symfony/Component/HttpFoundation/Response.php
index 331aad2610..abf8011794 100644
--- a/src/Symfony/Component/HttpFoundation/Response.php
+++ b/src/Symfony/Component/HttpFoundation/Response.php
@@ -513,13 +513,19 @@ class Response
     }
 
     /**
-     * Returns true if the response is worth caching under any circumstance.
+     * Returns true if the response may safely be kept in a shared (surrogate) cache.
      *
      * Responses marked "private" with an explicit Cache-Control directive are
      * considered uncacheable.
      *
      * Responses with neither a freshness lifetime (Expires, max-age) nor cache
-     * validator (Last-Modified, ETag) are considered uncacheable.
+     * validator (Last-Modified, ETag) are considered uncacheable because there is
+     * no way to tell when or how to remove them from the cache.
+     *
+     * Note that RFC 7231 and RFC 7234 possibly allow for a more permissive implementation,
+     * for example "status codes that are defined as cacheable by default [...]
+     * can be reused by a cache with heuristic expiration unless otherwise indicated"
+     * (https://tools.ietf.org/html/rfc7231#section-6.1)
      *
      * @return bool true if the response is worth caching, false otherwise
      */
diff --git a/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php b/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php
index 027b2b1761..672cc893fe 100644
--- a/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php
+++ b/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php
@@ -72,7 +72,7 @@ class ResponseCacheStrategy implements ResponseCacheStrategyInterface
             $response->setLastModified(null);
         }
 
-        if (!$response->isFresh()) {
+        if (!$response->isFresh() || !$response->isCacheable()) {
             $this->cacheable = false;
         }
 
diff --git a/src/Symfony/Component/HttpKernel/Tests/HttpCache/ResponseCacheStrategyTest.php b/src/Symfony/Component/HttpKernel/Tests/HttpCache/ResponseCacheStrategyTest.php
index 5e4c322223..6d67a17739 100644
--- a/src/Symfony/Component/HttpKernel/Tests/HttpCache/ResponseCacheStrategyTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/HttpCache/ResponseCacheStrategyTest.php
@@ -175,8 +175,26 @@ class ResponseCacheStrategyTest extends TestCase
         $cacheStrategy->update($masterResponse);
 
         $this->assertTrue($masterResponse->headers->hasCacheControlDirective('private'));
-        // Not sure if we should pass "max-age: 60" in this case, as long as the response is private and
-        // that's the more conservative of both the master and embedded response...?
+        $this->assertFalse($masterResponse->headers->hasCacheControlDirective('public'));
+    }
+
+    public function testEmbeddingPublicResponseDoesNotMakeMainResponsePublic()
+    {
+        $cacheStrategy = new ResponseCacheStrategy();
+
+        $masterResponse = new Response();
+        $masterResponse->setPrivate(); // this is the default, but let's be explicit
+        $masterResponse->setMaxAge(100);
+
+        $embeddedResponse = new Response();
+        $embeddedResponse->setPublic();
+        $embeddedResponse->setSharedMaxAge(100);
+
+        $cacheStrategy->add($embeddedResponse);
+        $cacheStrategy->update($masterResponse);
+
+        $this->assertTrue($masterResponse->headers->hasCacheControlDirective('private'));
+        $this->assertFalse($masterResponse->headers->hasCacheControlDirective('public'));
     }
 
     public function testResponseIsExiprableWhenEmbeddedResponseCombinesExpiryAndValidation()