Use display name instead of id for shared albums

[artonge]

Fix #1714

Before	After

[artonge]

/backport to stable26

[artonge]

/backport to stable25

[backportbot-nextcloud]

The backport to stable26 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable26
git pull origin/stable26

# Create the new backport branch
git checkout -b fix/foo-stable26

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable26

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport

[backportbot-nextcloud]

The backport to stable25 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable25
git pull origin/stable25

# Create the new backport branch
git checkout -b fix/foo-stable25

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable25

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport

[pulsejet]

I just want to point out that this potentially makes the name of the album ambiguous. For example, if two users with the same display name share an album with the same name to a user, then there's a conflict, and moving files to the album is ambiguous.

Notably, this could be an attack vector, since both the album name and display name can be changed by the user sharing the album. Of course there are non-malicious cases too, for example, two users named "Alice" sharing an album named "Christmas 2022" with Bob. The earlier behavior of using the username, on the other hand, was completely unambiguous.

@artonge @skjnldsv

[artonge]

Ah yes indeed, that might have been why I used user ID back then. We could revert, but as userid is not really made for display, then we end up with potentially weird titles.

Other options could be to add both, display name then userid. Userid would be less visible. Or to add a title saying something like "Shared by userid".

We could also rethink how we list shared albums. Maybe having a section per users:

Display name 1 (userid1):
Album name 1 Album name 2 ....

Display name 2 (userid2):
....

@nextcloud/designers an opinion ?

[nimishavijay]

Interesting problem! We generally don't use user IDs for display anywhere. There are cases even in other apps where this could happen, for example an event in a calendar with another person, or a file shared. So I think we can stick with showing just the display name :) We can always show the full name, which would help to differentiate to a certain extent.

[pulsejet]

I'm not talking about UX. I think the UX is fine, but there is a correctness problem that stems from the lexical DAV API (i.e. we can no longer uniquely identify the two albums).

If we just (for example) used IDs to identify albums, then this issue would never arise. It would then even be perfectly valid to have two albums with the same name for one user, which we can't have right now because of the artificial limitation that the DAV API adds.

[artonge]

Revert and improvement of the UI here: #1786