diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index 655e95cf93..c14399c0c6 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -423,7 +423,7 @@ class Configuration implements ConfigurationInterface
                                     ->addDefaultChildrenIfNoneSet()
                                     ->prototype('scalar')->defaultValue('FrameworkBundle:Form')->end()
                                     ->validate()
-                                        ->ifNotInArray(array('FrameworkBundle:Form'))
+                                        ->ifTrue(function ($v) {return !in_array('FrameworkBundle:Form', $v); })
                                         ->then(function ($v) {
                                             return array_merge(array('FrameworkBundle:Form'), $v);
                                         })
diff --git a/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateFilenameParser.php b/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateFilenameParser.php
index a4a5e92cf3..df3ab19c4d 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateFilenameParser.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateFilenameParser.php
@@ -31,7 +31,7 @@ class TemplateFilenameParser implements TemplateNameParserInterface
             return $name;
         }
 
-        $parts = explode('/', strtr($name, '\\', '/'));
+        $parts = explode('/', str_replace('\\', '/', $name));
 
         $elements = explode('.', array_pop($parts));
         if (3 > count($elements)) {
diff --git a/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateNameParser.php b/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateNameParser.php
index 5730807fac..e4a7053d25 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateNameParser.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Templating/TemplateNameParser.php
@@ -49,7 +49,7 @@ class TemplateNameParser extends BaseTemplateNameParser
         }
 
         // normalize name
-        $name = str_replace(':/', ':', preg_replace('#/{2,}#', '/', strtr($name, '\\', '/')));
+        $name = str_replace(':/', ':', preg_replace('#/{2,}#', '/', str_replace('\\', '/', $name)));
 
         if (false !== strpos($name, '..')) {
             throw new \RuntimeException(sprintf('Template name "%s" contains invalid characters.', $name));
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
index 47482433a9..89777ac44f 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
@@ -27,6 +27,19 @@ class ConfigurationTest extends \PHPUnit_Framework_TestCase
         );
     }
 
+    public function testDoNoDuplicateDefaultFormResources()
+    {
+        $input = array('templating' => array(
+            'form' => array('resources' => array('FrameworkBundle:Form')),
+            'engines' => array('php'),
+        ));
+
+        $processor = new Processor();
+        $config = $processor->processConfiguration(new Configuration(), array($input));
+
+        $this->assertEquals(array('FrameworkBundle:Form'), $config['templating']['form']['resources']);
+    }
+
     /**
      * @dataProvider getTestValidTrustedProxiesData
      */
diff --git a/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
index 9056ea299e..52c70f3318 100644
--- a/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
@@ -81,7 +81,7 @@ class Configuration implements ConfigurationInterface
                             ->prototype('scalar')->defaultValue('form_div_layout.html.twig')->end()
                             ->example(array('MyBundle::form.html.twig'))
                             ->validate()
-                                ->ifNotInArray(array('form_div_layout.html.twig'))
+                                ->ifTrue(function ($v) {return !in_array('form_div_layout.html.twig', $v); })
                                 ->then(function ($v) {
                                     return array_merge(array('form_div_layout.html.twig'), $v);
                                 })
diff --git a/src/Symfony/Bundle/TwigBundle/Tests/DependencyInjection/ConfigurationTest.php b/src/Symfony/Bundle/TwigBundle/Tests/DependencyInjection/ConfigurationTest.php
new file mode 100644
index 0000000000..7160345fd3
--- /dev/null
+++ b/src/Symfony/Bundle/TwigBundle/Tests/DependencyInjection/ConfigurationTest.php
@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bundle\TwigBundle\Tests\DependencyInjection;
+
+use Symfony\Bundle\TwigBundle\DependencyInjection\Configuration;
+use Symfony\Component\Config\Definition\Processor;
+
+class ConfigurationTest extends \PHPUnit_Framework_TestCase
+{
+    public function testDoNoDuplicateDefaultFormResources()
+    {
+        $input = array(
+            'form' => array('resources' => array('form_div_layout.html.twig')),
+        );
+
+        $processor = new Processor();
+        $config = $processor->processConfiguration(new Configuration(), array($input));
+
+        $this->assertEquals(array('form_div_layout.html.twig'), $config['form']['resources']);
+    }
+}
diff --git a/src/Symfony/Component/ClassLoader/Tests/ClassMapGeneratorTest.php b/src/Symfony/Component/ClassLoader/Tests/ClassMapGeneratorTest.php
index e6756f1898..7bdf5aa0dc 100644
--- a/src/Symfony/Component/ClassLoader/Tests/ClassMapGeneratorTest.php
+++ b/src/Symfony/Component/ClassLoader/Tests/ClassMapGeneratorTest.php
@@ -140,10 +140,10 @@ class ClassMapGeneratorTest extends \PHPUnit_Framework_TestCase
     protected function assertEqualsNormalized($expected, $actual, $message = null)
     {
         foreach ($expected as $ns => $path) {
-            $expected[$ns] = strtr($path, '\\', '/');
+            $expected[$ns] = str_replace('\\', '/', $path);
         }
         foreach ($actual as $ns => $path) {
-            $actual[$ns] = strtr($path, '\\', '/');
+            $actual[$ns] = str_replace('\\', '/', $path);
         }
         $this->assertEquals($expected, $actual, $message);
     }
diff --git a/src/Symfony/Component/Filesystem/Filesystem.php b/src/Symfony/Component/Filesystem/Filesystem.php
index 4a77f939ad..1e62b4d05d 100644
--- a/src/Symfony/Component/Filesystem/Filesystem.php
+++ b/src/Symfony/Component/Filesystem/Filesystem.php
@@ -329,8 +329,8 @@ class Filesystem
     {
         // Normalize separators on Windows
         if ('\\' === DIRECTORY_SEPARATOR) {
-            $endPath = strtr($endPath, '\\', '/');
-            $startPath = strtr($startPath, '\\', '/');
+            $endPath = str_replace('\\', '/', $endPath);
+            $startPath = str_replace('\\', '/', $startPath);
         }
 
         // Split the paths into arrays
diff --git a/src/Symfony/Component/Finder/Iterator/ExcludeDirectoryFilterIterator.php b/src/Symfony/Component/Finder/Iterator/ExcludeDirectoryFilterIterator.php
index 1ddde851b9..f15d953e4d 100644
--- a/src/Symfony/Component/Finder/Iterator/ExcludeDirectoryFilterIterator.php
+++ b/src/Symfony/Component/Finder/Iterator/ExcludeDirectoryFilterIterator.php
@@ -43,7 +43,7 @@ class ExcludeDirectoryFilterIterator extends FilterIterator
     public function accept()
     {
         $path = $this->isDir() ? $this->current()->getRelativePathname() : $this->current()->getRelativePath();
-        $path = strtr($path, '\\', '/');
+        $path = str_replace('\\', '/', $path);
         foreach ($this->patterns as $pattern) {
             if (preg_match($pattern, $path)) {
                 return false;
diff --git a/src/Symfony/Component/Finder/Iterator/PathFilterIterator.php b/src/Symfony/Component/Finder/Iterator/PathFilterIterator.php
index 2bb8ebd223..4971692c69 100644
--- a/src/Symfony/Component/Finder/Iterator/PathFilterIterator.php
+++ b/src/Symfony/Component/Finder/Iterator/PathFilterIterator.php
@@ -29,7 +29,7 @@ class PathFilterIterator extends MultiplePcreFilterIterator
         $filename = $this->current()->getRelativePathname();
 
         if ('\\' === DIRECTORY_SEPARATOR) {
-            $filename = strtr($filename, '\\', '/');
+            $filename = str_replace('\\', '/', $filename);
         }
 
         // should at least not match one rule to exclude