Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/translation/Dumper/PoFileDumper.php

@@ -0,0 +1,61 @@
+<?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\Component\Translation\Dumper;
+
+use Symfony\Component\Translation\MessageCatalogue;
+
+/**
+ * PoFileDumper generates a gettext formatted string representation of a message catalogue.
+ *
+ * @author Stealth35
+ */
+class PoFileDumper extends FileDumper
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function format(MessageCatalogue $messages, $domain = 'messages')
+    {
+        $output = 'msgid ""'."\n";
+        $output .= 'msgstr ""'."\n";
+        $output .= '"Content-Type: text/plain; charset=UTF-8\n"'."\n";
+        $output .= '"Content-Transfer-Encoding: 8bit\n"'."\n";
+        $output .= '"Language: '.$messages->getLocale().'\n"'."\n";
+        $output .= "\n";
+
+        $newLine = false;
+        foreach ($messages->all($domain) as $source => $target) {
+            if ($newLine) {
+                $output .= "\n";
+            } else {
+                $newLine = true;
+            }
+            $output .= sprintf('msgid "%s"'."\n", $this->escape($source));
+            $output .= sprintf('msgstr "%s"', $this->escape($target));
+        }
+
+        return $output;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function getExtension()
+    {
+        return 'po';
+    }
+
+    private function escape($str)
+    {
+        return addcslashes($str, "\0..\37\42\134");
+    }
+}