Identical file ids on public link uploads

[JammingBen]

Steps to reproduce

1. Create a public link
2. Upload a file to this public link
3. Do a PROPFIND request on the newly uploaded file (e.g. https://localhost:9200/remote.php/dav/public-files/PPqEGcHJCRrjAwn/file.pdf) and note the fileId from the response somewhere
4. Upload another file to this public link
5. Do a PROPFIND request on the second uploaded file (e.g. https://localhost:9200/remote.php/dav/public-files/PPqEGcHJCRrjAwn/another_file.pdf) and note the fileId from the response as well

Expected behavior

Those two ids should differ as we have two different files.

Actual behavior

Those two ids are identical. It's probably the id of the shared resource, not of the uploaded file.

[micbar]

Fix is available.