Copying zero byte file returns 201 status code but is not successful

[pascalwengerter]

Steps to reproduce

Steps to reproduce the behavior:

1. Go to https://ocis.ocis-web.latest.owncloud.works
2. Create folder in root, upload zero byte file to root
3. Try to copy zero byte file to folder

Expected behavior

Copy of zero byte file exists inside folder

Actual behavior

No file in copy target folder (yet the copy request has a status code of 201)

Note

This was discovered by an acceptance test in web. My workaround for the acceptance test suite was to upload a file with >0 byte content 🤷🏽 debatable whether we should test both scenarios, but at least discovered this bug...

[wkloucek]

Will be fixed by cs3org/reva#2374