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

vendor/zendframework/zend-feed/src/Writer/ExtensionPluginManager.php

@@ -0,0 +1,80 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link      http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   http://framework.zend.com/license/new-bsd New BSD License
+ */
+
+namespace Zend\Feed\Writer;
+
+use Zend\ServiceManager\AbstractPluginManager;
+
+/**
+ * Plugin manager implementation for feed writer extensions
+ *
+ * Validation checks that we have an Entry, Feed, or Extension\AbstractRenderer.
+ */
+class ExtensionPluginManager extends AbstractPluginManager
+{
+    /**
+     * Default set of extension classes
+     *
+     * @var array
+     */
+    protected $invokableClasses = [
+        'atomrendererfeed'           => 'Zend\Feed\Writer\Extension\Atom\Renderer\Feed',
+        'contentrendererentry'       => 'Zend\Feed\Writer\Extension\Content\Renderer\Entry',
+        'dublincorerendererentry'    => 'Zend\Feed\Writer\Extension\DublinCore\Renderer\Entry',
+        'dublincorerendererfeed'     => 'Zend\Feed\Writer\Extension\DublinCore\Renderer\Feed',
+        'itunesentry'                => 'Zend\Feed\Writer\Extension\ITunes\Entry',
+        'itunesfeed'                 => 'Zend\Feed\Writer\Extension\ITunes\Feed',
+        'itunesrendererentry'        => 'Zend\Feed\Writer\Extension\ITunes\Renderer\Entry',
+        'itunesrendererfeed'         => 'Zend\Feed\Writer\Extension\ITunes\Renderer\Feed',
+        'slashrendererentry'         => 'Zend\Feed\Writer\Extension\Slash\Renderer\Entry',
+        'threadingrendererentry'     => 'Zend\Feed\Writer\Extension\Threading\Renderer\Entry',
+        'wellformedwebrendererentry' => 'Zend\Feed\Writer\Extension\WellFormedWeb\Renderer\Entry',
+    ];
+
+    /**
+     * Do not share instances
+     *
+     * @var bool
+     */
+    protected $shareByDefault = false;
+
+    /**
+     * Validate the plugin
+     *
+     * Checks that the extension loaded is of a valid type.
+     *
+     * @param  mixed $plugin
+     * @return void
+     * @throws Exception\InvalidArgumentException if invalid
+     */
+    public function validatePlugin($plugin)
+    {
+        if ($plugin instanceof Extension\AbstractRenderer) {
+            // we're okay
+            return;
+        }
+
+        if ('Feed' == substr(get_class($plugin), -4)) {
+            // we're okay
+            return;
+        }
+
+        if ('Entry' == substr(get_class($plugin), -5)) {
+            // we're okay
+            return;
+        }
+
+        throw new Exception\InvalidArgumentException(sprintf(
+            'Plugin of type %s is invalid; must implement %s\Extension\RendererInterface '
+            . 'or the classname must end in "Feed" or "Entry"',
+            (is_object($plugin) ? get_class($plugin) : gettype($plugin)),
+            __NAMESPACE__
+        ));
+    }
+}