add recursive copy polyfill for storage backends

lib/private/files/storage/polyfill/copydirectory.php

@@ -0,0 +1,61 @@
+<?php
+/**
+ * Copyright (c) 2015 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Files\Storage\PolyFill;
+
+trait CopyDirectory {
+	abstract public function is_dir($path);
+
+	abstract public function file_exists($path);
+
+	abstract public function buildPath($path);
+
+	abstract public function unlink($path);
+
+	abstract public function opendir($path);
+
+	abstract public function mkdir($path);
+
+	public function copy($source, $target) {
+		if ($this->is_dir($source)) {
+			if ($this->file_exists($target)) {
+				$this->unlink($target);
+			}
+			parent::copy($source, $target);
+			return $this->copyRecursive($source, $target);
+		} else {
+			return parent::copy($source, $target);
+		}
+	}
+
+	/**
+	 * For adapters that dont support copying folders natively
+	 *
+	 * @param $source
+	 * @param $target
+	 * @return bool
+	 */
+	protected function copyRecursive($source, $target) {
+		$dh = $this->opendir($source);
+		$result = true;
+		while ($file = readdir($dh)) {
+			if ($file !== '.' and $file !== '..') {
+				if ($this->is_dir($source . '/' . $file)) {
+					$this->mkdir($target . '/' . $file);
+					$result = $this->copyRecursive($source . '/' . $file, $target . '/' . $file);
+				} else {
+					$result = parent::copy($source . '/' . $file, $target . '/' . $file);
+				}
+				if (!$result) {
+					break;
+				}
+			}
+		}
+		return $result;
+	}
+}