diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_dev.php b/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_dev.php
index 64c90b4bd2..9e70bf7acd 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_dev.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_dev.php
@@ -25,6 +25,7 @@ if (is_file($_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.$_SERVER['SCRIPT_NAME'
     return false;
 }
 
+$_SERVER = array_merge($_SERVER, $_ENV);
 $_SERVER['SCRIPT_FILENAME'] = $_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.'app_dev.php';
 
 require 'app_dev.php';
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_prod.php b/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_prod.php
index 4278b4bba1..a3ef29d8db 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_prod.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/router_prod.php
@@ -25,6 +25,7 @@ if (is_file($_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.$_SERVER['SCRIPT_NAME'
     return false;
 }
 
+$_SERVER = array_merge($_SERVER, $_ENV);
 $_SERVER['SCRIPT_FILENAME'] = $_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.'app.php';
 
 require 'app.php';
diff --git a/src/Symfony/Component/Finder/Shell/Shell.php b/src/Symfony/Component/Finder/Shell/Shell.php
index 8586cbc3e5..d17f2fac35 100644
--- a/src/Symfony/Component/Finder/Shell/Shell.php
+++ b/src/Symfony/Component/Finder/Shell/Shell.php
@@ -50,17 +50,19 @@ class Shell
      */
     public function testCommand($command)
     {
-        if (self::TYPE_WINDOWS === $this->type) {
-            // todo: find a way to test if Windows command exists
-            return false;
-        }
-
         if (!function_exists('exec')) {
             return false;
         }
 
         // todo: find a better way (command could not be available)
-        exec('command -v '.$command, $output, $code);
+        $testCommand = 'which ';
+        if (self::TYPE_WINDOWS === $this->type) {
+            $testCommand = 'where ';
+        }
+
+        $command = escapeshellcmd($command);
+
+        exec($testCommand.$command, $output, $code);
 
         return 0 === $code && count($output) > 0;
     }
diff --git a/src/Symfony/Component/Form/CallbackTransformer.php b/src/Symfony/Component/Form/CallbackTransformer.php
index c53c6df788..03459d4e8a 100644
--- a/src/Symfony/Component/Form/CallbackTransformer.php
+++ b/src/Symfony/Component/Form/CallbackTransformer.php
@@ -18,24 +18,33 @@ class CallbackTransformer implements DataTransformerInterface
 {
     /**
      * The callback used for forward transform
-     * @var \Closure
+     * @var callable
      */
     private $transform;
 
     /**
      * The callback used for reverse transform
-     * @var \Closure
+     * @var callable
      */
     private $reverseTransform;
 
     /**
      * Constructor.
      *
-     * @param \Closure $transform        The forward transform callback
-     * @param \Closure $reverseTransform The reverse transform callback
+     * @param callable $transform        The forward transform callback
+     * @param callable $reverseTransform The reverse transform callback
+     *
+     * @throws \InvalidArgumentException when the given callbacks is invalid
      */
-    public function __construct(\Closure $transform, \Closure $reverseTransform)
+    public function __construct($transform, $reverseTransform)
     {
+        if (!is_callable($transform)) {
+            throw new \InvalidArgumentException('Argument 1 should be a callable');
+        }
+        if (!is_callable($reverseTransform)) {
+            throw new \InvalidArgumentException('Argument 2 should be a callable');
+        }
+
         $this->transform = $transform;
         $this->reverseTransform = $reverseTransform;
     }
@@ -47,7 +56,7 @@ class CallbackTransformer implements DataTransformerInterface
      *
      * @return mixed The value in the transformed representation
      *
-     * @throws UnexpectedTypeException       when the argument is not a string
+     * @throws UnexpectedTypeException       when the argument is not of the expected type
      * @throws TransformationFailedException when the transformation fails
      */
     public function transform($data)
diff --git a/src/Symfony/Component/Form/Tests/CallbackTransformerTest.php b/src/Symfony/Component/Form/Tests/CallbackTransformerTest.php
new file mode 100644
index 0000000000..706bc076ec
--- /dev/null
+++ b/src/Symfony/Component/Form/Tests/CallbackTransformerTest.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Symfony\Component\Form\Tests;
+
+use Symfony\Component\Form\CallbackTransformer;
+
+class CallbackTransformerTest extends \PHPUnit_Framework_TestCase
+{
+    public function testTransform()
+    {
+        $transformer = new CallbackTransformer(
+            function($value) { return $value.' has been transformed'; },
+            function($value) { return $value.' has reversely been transformed'; }
+        );
+
+        $this->assertEquals('foo has been transformed', $transformer->transform('foo'));
+        $this->assertEquals('bar has reversely been transformed', $transformer->reverseTransform('bar'));
+    }
+
+    /**
+     * @dataProvider invalidCallbacksProvider
+     *
+     * @expectedException \InvalidArgumentException
+     */
+    public function testConstructorWithInvalidCallbacks($transformCallback, $reverseTransformCallback)
+    {
+        new CallbackTransformer($transformCallback, $reverseTransformCallback);
+    }
+
+    public function invalidCallbacksProvider()
+    {
+        return array(
+            array( null, function(){} ),
+            array( function(){}, null ),
+        );
+    }
+}
diff --git a/src/Symfony/Component/Process/Tests/AbstractProcessTest.php b/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
index 762651465f..03d602476d 100644
--- a/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
+++ b/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
@@ -260,13 +260,23 @@ abstract class AbstractProcessTest extends \PHPUnit_Framework_TestCase
 
     public function testGetIncrementalErrorOutput()
     {
-        $p = $this->getProcess(sprintf('php -r %s', escapeshellarg('$n = 0; while ($n < 3) { usleep(100000); file_put_contents(\'php://stderr\', \'ERROR\'); $n++; }')));
+        // use a lock file to toggle between writing ("W") and reading ("R") the
+        // error stream
+        $lock = tempnam(sys_get_temp_dir(), get_class($this).'Lock');
+        file_put_contents($lock, 'W');
+
+        $p = $this->getProcess(sprintf('php -r %s', escapeshellarg('$n = 0; while ($n < 3) { if (\'W\' === file_get_contents('.var_export($lock, true).')) { file_put_contents(\'php://stderr\', \'ERROR\'); $n++; file_put_contents('.var_export($lock, true).', \'R\'); } usleep(100); }')));
 
         $p->start();
         while ($p->isRunning()) {
-            $this->assertLessThanOrEqual(1, preg_match_all('/ERROR/', $p->getIncrementalErrorOutput(), $matches));
-            usleep(20000);
+            if ('R' === file_get_contents($lock)) {
+                $this->assertLessThanOrEqual(1, preg_match_all('/ERROR/', $p->getIncrementalErrorOutput(), $matches));
+                file_put_contents($lock, 'W');
+            }
+            usleep(100);
         }
+
+        unlink($lock);
     }
 
     public function testFlushErrorOutput()
@@ -280,7 +290,7 @@ abstract class AbstractProcessTest extends \PHPUnit_Framework_TestCase
 
     public function testGetOutput()
     {
-        $p = $this->getProcess(sprintf('php -r %s', escapeshellarg('$n=0;while ($n<3) {echo \' foo \';$n++; usleep(500); }')));
+        $p = $this->getProcess(sprintf('php -r %s', escapeshellarg('$n = 0; while ($n < 3) { echo \' foo \'; $n++; }')));
 
         $p->run();
         $this->assertEquals(3, preg_match_all('/foo/', $p->getOutput(), $matches));
@@ -288,13 +298,23 @@ abstract class AbstractProcessTest extends \PHPUnit_Framework_TestCase
 
     public function testGetIncrementalOutput()
     {
-        $p = $this->getProcess(sprintf('php -r %s', escapeshellarg('$n=0;while ($n<3) { echo \' foo \'; usleep(50000); $n++; }')));
+        // use a lock file to toggle between writing ("W") and reading ("R") the
+        // output stream
+        $lock = tempnam(sys_get_temp_dir(), get_class($this).'Lock');
+        file_put_contents($lock, 'W');
+
+        $p = $this->getProcess(sprintf('php -r %s', escapeshellarg('$n = 0; while ($n < 3) { if (\'W\' === file_get_contents('.var_export($lock, true).')) { echo \' foo \'; $n++; file_put_contents('.var_export($lock, true).', \'R\'); } usleep(100); }')));
 
         $p->start();
         while ($p->isRunning()) {
-            $this->assertLessThanOrEqual(1, preg_match_all('/foo/', $p->getIncrementalOutput(), $matches));
-            usleep(20000);
+            if ('R' === file_get_contents($lock)) {
+                $this->assertLessThanOrEqual(1, preg_match_all('/foo/', $p->getIncrementalOutput(), $matches));
+                file_put_contents($lock, 'W');
+            }
+            usleep(100);
         }
+
+        unlink($lock);
     }
 
     public function testFlushOutput()