This change makes sure that each Nextcloud plugin installed provides a
`meta` section with proper license information.
Unfortunately, the metadata from the appstore is useless for this
purpose since it doesn't differentiate between e.g. AGPL 3.x and AGPL
3.x or any later version. In fact, this isn't consistent between their
software, e.g. `bookmarks` has `agpl3Plus` according to the files'
headers[1] whereas `twofactor_nextcloud_notification` is AGPL 3 only[2].
I don't think there's any trivial and reasonable way to retrieve this
information programatically, so I decided to change the format of
`nextcloud-apps.json`[3] to also contain the license in the form of the
license attribute we have in `lib/licenses.nix`, i.e. GNU AGPL 3 or
later is `agpl3Plus`.
I retrieved the information using the following approach:
* go to the source code of $app at the revision we currently have
packaged
* check for a license identifier (does it specify the license only or
the license "or any later version")?
* first in `src/main.js` because most apps from Nextcloud itself used
actual spdx identifiers in the frontend's source-code.
* then in `lib/AppInfo/Application.php` which each Nextcloud app has.
License changes should be updated accordingly when updating the apps. As
with any other package in nixpkgs as well, this currently needs to be
done manually (or as part of the review process)[4].
Also, I decided to change the `name` of the `applyPatches` derivation
from `source-patched` to `nextcloud-app-${appName}-${appVersion}`. When
deploying a lot of apps (and probably displaying the diff using
`nix store diff-closures` on deploy), the current output isn't very
helpful. This is purely optional because I didn't want to break the
interface of `fetchNextcloudApp` again.
[1] https://github.com/nextcloud/bookmarks/blob/v13.1.0/lib/AppInfo/Application.php#L6
[2] https://github.com/nextcloud/twofactor_nextcloud_notification/blob/v3.7.0/lib/AppInfo/Application.php
[3] This isn't really well-defined since it's preprocessed with `jq(1)`
before passing the apps to nc4nix.
[4] Though notable license changes (e.g. agpl -> gpl) would also pop up
in the diff of <nextcloudversion>.json, so this is pretty easy to
catch.
Robert Schützandgador