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

vendor/masterminds/html5/src/HTML5/Serializer/Traverser.php

@@ -0,0 +1,150 @@
+<?php
+namespace Masterminds\HTML5\Serializer;
+
+/**
+ * Traverser for walking a DOM tree.
+ *
+ * This is a concrete traverser designed to convert a DOM tree into an
+ * HTML5 document. It is not intended to be a generic DOMTreeWalker
+ * implementation.
+ *
+ * @see http://www.w3.org/TR/2012/CR-html5-20121217/syntax.html#serializing-html-fragments
+ */
+class Traverser
+{
+
+    /**
+     * Namespaces that should be treated as "local" to HTML5.
+     */
+    static $local_ns = array(
+        'http://www.w3.org/1999/xhtml' => 'html',
+        'http://www.w3.org/1998/Math/MathML' => 'math',
+        'http://www.w3.org/2000/svg' => 'svg'
+    );
+
+    protected $dom;
+
+    protected $options;
+
+    protected $encode = false;
+
+    protected $rules;
+
+    protected $out;
+
+    /**
+     * Create a traverser.
+     *
+     * @param DOMNode|DOMNodeList $dom
+     *            The document or node to traverse.
+     * @param resource $out
+     *            A stream that allows writing. The traverser will output into this
+     *            stream.
+     * @param array $options
+     *            An array or options for the traverser as key/value pairs. These include:
+     *            - encode_entities: A bool to specify if full encding should happen for all named
+     *            charachter references. Defaults to false which escapes &'<>".
+     *            - output_rules: The path to the class handling the output rules.
+     */
+    public function __construct($dom, $out, RulesInterface $rules, $options = array())
+    {
+        $this->dom = $dom;
+        $this->out = $out;
+        $this->rules = $rules;
+        $this->options = $options;
+
+        $this->rules->setTraverser($this);
+    }
+
+    /**
+     * Tell the traverser to walk the DOM.
+     *
+     * @return resource $out
+     *         Returns the output stream.
+     */
+    public function walk()
+    {
+        if ($this->dom instanceof \DOMDocument) {
+            $this->rules->document($this->dom);
+        } elseif ($this->dom instanceof \DOMDocumentFragment) {
+            // Document fragments are a special case. Only the children need to
+            // be serialized.
+            if ($this->dom->hasChildNodes()) {
+                $this->children($this->dom->childNodes);
+            }
+        }        // If NodeList, loop
+        elseif ($this->dom instanceof \DOMNodeList) {
+            // If this is a NodeList of DOMDocuments this will not work.
+            $this->children($this->dom);
+        }         // Else assume this is a DOMNode-like datastructure.
+        else {
+            $this->node($this->dom);
+        }
+
+        return $this->out;
+    }
+
+    /**
+     * Process a node in the DOM.
+     *
+     * @param mixed $node
+     *            A node implementing \DOMNode.
+     */
+    public function node($node)
+    {
+        // A listing of types is at http://php.net/manual/en/dom.constants.php
+        switch ($node->nodeType) {
+            case XML_ELEMENT_NODE:
+                $this->rules->element($node);
+                break;
+            case XML_TEXT_NODE:
+                $this->rules->text($node);
+                break;
+            case XML_CDATA_SECTION_NODE:
+                $this->rules->cdata($node);
+                break;
+            // FIXME: It appears that the parser doesn't do PI's.
+            case XML_PI_NODE:
+                $this->rules->processorInstruction($node);
+                break;
+            case XML_COMMENT_NODE:
+                $this->rules->comment($node);
+                break;
+            // Currently we don't support embedding DTDs.
+            default:
+                //print '<!-- Skipped -->';
+                break;
+        }
+    }
+
+    /**
+     * Walk through all the nodes on a node list.
+     *
+     * @param \DOMNodeList $nl
+     *            A list of child elements to walk through.
+     */
+    public function children($nl)
+    {
+        foreach ($nl as $node) {
+            $this->node($node);
+        }
+    }
+
+    /**
+     * Is an element local?
+     *
+     * @param mixed $ele
+     *            An element that implement \DOMNode.
+     *
+     * @return bool True if local and false otherwise.
+     */
+    public function isLocalElement($ele)
+    {
+        $uri = $ele->namespaceURI;
+        if (empty($uri)) {
+            return false;
+        }
+
+        return isset(static::$local_ns[$uri]);
+    }
+}