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

vendor/symfony/css-selector/Parser/Handler/IdentifierHandler.php

@@ -0,0 +1,67 @@
+<?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\CssSelector\Parser\Handler;
+
+use Symfony\Component\CssSelector\Parser\Reader;
+use Symfony\Component\CssSelector\Parser\Token;
+use Symfony\Component\CssSelector\Parser\TokenStream;
+use Symfony\Component\CssSelector\Parser\Tokenizer\TokenizerEscaping;
+use Symfony\Component\CssSelector\Parser\Tokenizer\TokenizerPatterns;
+
+/**
+ * CSS selector comment handler.
+ *
+ * This component is a port of the Python cssselect library,
+ * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
+ *
+ * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
+ */
+class IdentifierHandler implements HandlerInterface
+{
+    /**
+     * @var TokenizerPatterns
+     */
+    private $patterns;
+
+    /**
+     * @var TokenizerEscaping
+     */
+    private $escaping;
+
+    /**
+     * @param TokenizerPatterns $patterns
+     * @param TokenizerEscaping $escaping
+     */
+    public function __construct(TokenizerPatterns $patterns, TokenizerEscaping $escaping)
+    {
+        $this->patterns = $patterns;
+        $this->escaping = $escaping;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function handle(Reader $reader, TokenStream $stream)
+    {
+        $match = $reader->findPattern($this->patterns->getIdentifierPattern());
+
+        if (!$match) {
+            return false;
+        }
+
+        $value = $this->escaping->escapeUnicode($match[0]);
+        $stream->push(new Token(Token::TYPE_IDENTIFIER, $value, $reader->getPosition()));
+        $reader->moveForward(strlen($match[0]));
+
+        return true;
+    }
+}