Use user mount with matching shared storage only

Signed-off-by: Julius Härtl <jus@bitgrid.net>

diff --git a/lib/private/Share20/Manager.php b/lib/private/Share20/Manager.php
index 3b022f5951c13dfd7604cca0d0f6652ba7b5ffcd..216f93c778cd2ac1f6633f64e9240c63829e33c9 100644 (file)
--- a/lib/private/Share20/Manager.php
+++ b/lib/private/Share20/Manager.php
@@ -43,6 +43,7 @@ use OC\Cache\CappedMemoryCache;
 use OC\Files\Mount\MoveableMount;
 use OC\HintException;
 use OC\Share20\Exception\ProviderException;
+use OCA\Files_Sharing\ISharedStorage;
 use OCP\EventDispatcher\IEventDispatcher;
 use OCP\Files\File;
 use OCP\Files\Folder;
@@ -299,10 +300,17 @@ class Manager implements IManager {
                $isFederatedShare = $share->getNode()->getStorage()->instanceOfStorage('\OCA\Files_Sharing\External\Storage');
                $permissions = 0;
 
-               $userMounts = $userFolder->getById($share->getNode()->getId());
-               $userMount = array_shift($userMounts);
-               $mount = $userMount->getMountPoint();
                if (!$isFederatedShare && $share->getNode()->getOwner() && $share->getNode()->getOwner()->getUID() !== $share->getSharedBy()) {
+                       $userMounts = array_filter($userFolder->getById($share->getNode()->getId()), function ($mount) {
+                               // We need to filter since there might be other mountpoints that contain the file
+                               // e.g. if the user has access to the same external storage that the file is originating from
+                               return $mount->getStorage()->instanceOfStorage(ISharedStorage::class);
+                       });
+                       $userMount = array_shift($userMounts);
+                       if ($userMount === null) {
+                               throw new GenericShareException('Could not get proper share mount for ' . $share->getNode()->getId() . '. Failing since else the next calls are called with null');
+                       }
+                       $mount = $userMount->getMountPoint();
                        // When it's a reshare use the parent share permissions as maximum
                        $userMountPointId = $mount->getStorageRootId();
                        $userMountPoints = $userFolder->getById($userMountPointId);
@@ -331,7 +339,7 @@ class Manager implements IManager {
                         * while we 'most likely' do have that on the storage.
                         */
                        $permissions = $share->getNode()->getPermissions();
-                       if (!($mount instanceof MoveableMount)) {
+                       if (!($share->getNode()->getMountPoint() instanceof MoveableMount)) {
                                $permissions |= \OCP\Constants::PERMISSION_DELETE | \OCP\Constants::PERMISSION_UPDATE;
                        }
                }