Share owner has no possibility to list all existing derived shares

How it was found

Hi,

I found a bug where a shared link of particular file can disclose all files of that folder.

Steps to reproduce

• Make a group( http://*/nextcloud/index.php/settings/users) and a standard user in it.

• Now goto any folder and change it to gallery view {F99993}

• Invite that group which u made in step 1 with share privilege .

• From standard user account, goto that shared folder and make a shared link of any file. E.g:

{F99992}

• Untick the can share privilege from that group using folder owner account. Eg:

{F99994}

Now the shared link which was created by standard user will work as folder shared link. And when folder untick the can share privilege public is automatically created without asking folder owner.

Thanks