Comment 8 for bug 1797860

Hey Gunnar,

After reorganizing the seeds for ubuntu desktop and see which strategy we are going to take for the new installer (negative layered langpacks, I can expand on this a little bit later), I think we have a robust story to avoid the unsync we have between language-selector and the installer/live image default list.

In disco (note: not available in the daily image which isn't including the langpacks until our livecd-rootfs MP is in production: https://code.launchpad.net/~jibel/livecd-rootfs/add_multi_layered_squashfses_support/+merge/358490)
* Basically, default language selection are now for the ubuntu desktop flavor seed:
https://git.launchpad.net/~ubuntu-core-dev/ubuntu-seeds/+git/ubuntu/tree/languages. There are 2 seeds for each language:
- the minimal one, corresponding to the new ubuntu-desktop-minimal package: https://git.launchpad.net/~ubuntu-core-dev/ubuntu-seeds/+git/ubuntu/tree/languages/desktop-minimal-de
- the "full" one, which, in addition to the desktop-minimal one has the dictionaries, libreoffice, thunderbird and mozilla translations: https://git.launchpad.net/~ubuntu-core-dev/ubuntu-seeds/+git/ubuntu/tree/languages/desktop-de

You can see that input methods are included in some, like the chinese one: https://git.launchpad.net/~ubuntu-core-dev/ubuntu-seeds/+git/ubuntu/tree/languages/desktop-minimal-zh (we may have some wrong assignement, if you spot anything, feel free!)

So, the idea would be:
- have, for the default languages, language-selector on ubuntu-desktop using those seeds (probably picking the list at package build time?). It needs to adapt depending on the installed metapackage (ubuntu-desktop-minimal or ubuntu-desktop). Note that ubuntu-desktop installs ubuntu-desktop-minimal.
- expand the heuristic for other languages for ubuntu-desktop-minimal/ubuntu-desktop. We can maybe include the regexp in the seed if that helps? That way, we have a single place where we define all languages support.

In addition to this:
- we remove the magic for "en" (enforcing too many time to install them). It isn't required if installing an other language
- installing one language, do, as of today, install all "deviations", like fr installs fr_FR, fr_CA, fr_BE, even if those are part of other binary packages. The default languages seed should already cover that.

The installer would then only rely on language-support to ensure everything installed is correctly there.

What do you think? Do you have some time to work on this for this cycle?