Sharing: only determine path root if owner is available

lib/public/share.php

@@ -209,7 +209,7 @@ class Share {
 					}
 				}
 			}
-			
+
 			// let's get the parent for the next round
 			$meta = $cache->get((int)$source);
 			if($meta !== false) {
@@ -840,7 +840,11 @@ class Share {
 		// Get filesystem root to add it to the file target and remove from the
 		// file source, match file_source with the file cache
 		if ($itemType == 'file' || $itemType == 'folder') {
-			$root = \OC\Files\Filesystem::getRoot();
+			if(!is_null($uidOwner)) {
+				$root = \OC\Files\Filesystem::getRoot();
+			} else {
+				$root = '';
+			}
 			$where = 'INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid`';
 			if (!isset($item)) {
 				$where .= ' WHERE `file_target` IS NOT NULL';
@@ -1303,11 +1307,11 @@ class Share {
 				'run' => &$run,
 				'error' => &$error
 			));
-			
+
 			if ($run === false) {
 				throw new \Exception($error);
 			}
-			
+
 			if (isset($fileSource)) {
 				if ($parentFolder) {
 					if ($parentFolder === true) {
@@ -1398,11 +1402,11 @@ class Share {
 				'run' => &$run,
 				'error' => &$error
 			));
-			
+
 			if ($run === false) {
 				throw new \Exception($error);
 			}
-			
+
 			if (isset($fileSource)) {
 				if ($parentFolder) {
 					if ($parentFolder === true) {