Delta language pack exports are not message sharing aware

[David Planella]

As part of the Ubuntu language pack infrastructure, Launchpad produces two types of regular translations exports:

* Delta exports
* Full exports

They are basically tarballs containing exported PO files that contain all translations done in Launchpad [1], to be used as the source to feed to langpack-o-matic [2], which will ultimately produce the .deb language packs which deliver translations to users.

Delta exports exist in order to periodically release only translations that have changed since the last language pack release. This implies a lot less to build, upload, and download for users.

However, we are not using the full potential of delta exports: the code that generates the delta exports ignores message sharing. This means that translations completed through message sharing are not considered as a change and are thus not exported.

In short, the delta export machinery in Launchpad should be message sharing aware.

[1] https://translations.launchpad.net/ubuntu/maverick/+language-packs
[2] https://launchpad.net/langpack-o-matic

[Данило Шеган (danilo)]

This is a regression compared to the previous functionality: it's been around for a while though.

[Данило Шеган (danilo)]

Btw, functionality used in pofile-stats-daily might come in handy here: there's already (tested) logic to figure out all related POFiles that have been changed.