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

vendor/symfony/validator/Util/PropertyPath.php

@@ -0,0 +1,58 @@
+<?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\Validator\Util;
+
+/**
+ * Contains utility methods for dealing with property paths.
+ *
+ * For more extensive functionality, use Symfony's PropertyAccess component.
+ *
+ * @since  2.5
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class PropertyPath
+{
+    /**
+     * Appends a path to a given property path.
+     *
+     * If the base path is empty, the appended path will be returned unchanged.
+     * If the base path is not empty, and the appended path starts with a
+     * squared opening bracket ("["), the concatenation of the two paths is
+     * returned. Otherwise, the concatenation of the two paths is returned,
+     * separated by a dot (".").
+     *
+     * @param string $basePath The base path
+     * @param string $subPath  The path to append
+     *
+     * @return string The concatenation of the two property paths
+     */
+    public static function append($basePath, $subPath)
+    {
+        if ('' !== (string) $subPath) {
+            if ('[' === $subPath{0}) {
+                return $basePath.$subPath;
+            }
+
+            return '' !== (string) $basePath ? $basePath.'.'.$subPath : $subPath;
+        }
+
+        return $basePath;
+    }
+
+    /**
+     * Not instantiable.
+     */
+    private function __construct()
+    {
+    }
+}