albums: check copy source owner is the current user and throw

[pulsejet]

The current behavior when trying to copy a shared file to an album is meaningless. Since the copyInto call returns false, DAV falls back to trying to create the file again with the same content (see this fallback). As a result,

1. The shared file gets copied over to the current user.
2. It gets added to the album.
3. The call fails anyway because the name of the destination node (that is copied inside the album) has changed, so the subsequent call to get the node from the album fails.

If we throw while copying, the user can't add shared files to albums anymore with a proper error message, and files don't get copied unnecessarily.

One thing to note here, I do think ideally there should be some way to add shared files to albums, as long as the file as resharing permissions. Of course then we might need to check later if the file is unshared and remove it from the album. Thoughts?

[artonge]

Indeed, much cleaner.
One small nitpick though

[artonge]

One thing to note here, I do think ideally there should be some way to add shared files to albums, as long as the file as resharing permissions. Of course then we might need to check later if the file is unshared and remove it from the album. Thoughts?

I don't remember why the limitation exists, but it was probably to reduce the complexity of the first version.
Could be a nice addition to support shared files 👍

[artonge]

/backport to stable26

[artonge]

/backport to stable25

[artonge]

/rebase