check item id is set

diff --git a/lib/public/share.php b/lib/public/share.php
index 122ab3fa03019717d15af5a199de0c493d2eaf48..d1000e7bb9f47e1925874e03826d92d95de31d1f 100644 (file)
--- a/lib/public/share.php
+++ b/lib/public/share.php
@@ -978,7 +978,7 @@ class Share {
                                        // Check if the same owner shared with the user twice
                                        // through a group and user share - this is allowed
                                        $id = $targets[$row[$column]];
-                                       if ($items[$id]['uid_owner'] == $row['uid_owner']) {
+                                       if (isset($items[$id]) && $items[$id]['uid_owner'] == $row['uid_owner']) {
                                                // Switch to group share type to ensure resharing conditions aren't bypassed
                                                if ($items[$id]['share_type'] != self::SHARE_TYPE_GROUP) {
                                                        $items[$id]['share_type'] = self::SHARE_TYPE_GROUP;