Merge branch '2.8' into 3.0

* 2.8:
  fixed test
  [Request] Ignore invalid IP addresses sent by proxies
  [EventDispatcher] TraceableEventDispatcher resets listener priorities
  Throw for missing container extensions
  [TwigBridge] add missing unit tests (AppVariable)
  Able to load big xml files with DomCrawler
  fixed typo
  [Form] Fix constraints could be null if not set
  [Finder] Check PHP version before applying a workaround for a PHP bug
  fixed CS
  add defaultNull to version
  sort bundles in config:dump-reference command
  Fixer findings.
  Profiler CSS position conflicts with JS detection
  [Translation][Writer] avoid calling setBackup if the dumper is not an instance of FileDumper.
  [FrameworkBundle] Compute the kernel root hash only one time

Author: fabpot

Tests/Writer/TranslationWriterTest.php

@@ -0,0 +1,47 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Translation\Tests\Writer;
+
+use Symfony\Component\Translation\MessageCatalogue;
+use Symfony\Component\Translation\Writer\TranslationWriter;
+
+class TranslationWriterTest extends \PHPUnit_Framework_TestCase
+{
+    public function testWriteTranslations()
+    {
+        $dumper = $this->getMock('Symfony\Component\Translation\Dumper\DumperInterface');
+        $dumper
+            ->expects($this->once())
+            ->method('dump');
+
+        $writer = new TranslationWriter();
+        $writer->addDumper('test', $dumper);
+        $writer->writeTranslations(new MessageCatalogue(array()), 'test');
+    }
+
+    public function testDisableBackup()
+    {
+        $dumper = $this->getMock('Symfony\Component\Translation\Dumper\DumperInterface');
+        $dumper
+            ->expects($this->never())
+            ->method('setBackup');
+        $phpDumper = $this->getMock('Symfony\Component\Translation\Dumper\PhpFileDumper');
+        $phpDumper
+            ->expects($this->once())
+            ->method('setBackup');
+
+        $writer = new TranslationWriter();
+        $writer->addDumper('test', $dumper);
+        $writer->addDumper('php', $phpDumper);
+        $writer->disableBackup();
+    }
+}

Writer/TranslationWriter.php

@@ -45,7 +45,9 @@ public function addDumper($format, DumperInterface $dumper)
     public function disableBackup()
     {
         foreach ($this->dumpers as $dumper) {
-            $dumper->setBackup(false);
+            if (method_exists($dumper, 'setBackup')) {
+                $dumper->setBackup(false);
+            }
         }
     }