.po file export doesn't update cached files

As confirmed in bug #68014, this happens to others too

Happen to me too, as I've described here: https://launchpad.net/products/rosetta/+bug/68014

Danilo tells me that he has debugged this and it seems to be caused by the fact that translation approvals don't update the latest submission flag; this particular bug could cause the workflow:

- add good, approved translation
- add poor, approved translation
- revert to old and good translation

to not trigger an update. We're still investigating.

It seems not to be as simple as that.

The problem seems to happen with https://translations.launchpad.net/wengophone/trunk/+pots/qtwengophone/es/2/+translate
where:

Current Spanish:
Contraseña:
Translated by: GuS on 2006-09-08 16:20:14 CEST
Reviewed by: GuS on 2006-11-25 20:00:04 CET

But exported value is one of the suggestions instead:

Contraseña:
Coming from: qtwengophone in WengoPhone trunk by GuS on 2006-11-07 14:24:30 CET

I'll probably have to look into poexport cache tables (which I currently don't have privileges to).

Ok, the above scenario seems to be required, but not enough. One should also export the file in between 2 and 3, which causes the following logic in database/pofile.py to fail:

    def validExportCache(self):
        ...
        change_time = self.latestsubmission.datecreated
        return change_time < self.exporttime

(in case of qtwengophone/es, self.exporttime is '2006-11-24 19:18:05.808967', i.e. a day before self.latestsubmission.active_selections[x].date_reviewed)

Now I need to create a testcase in sampledata for this.

There's another corner-case to be careful about: if translation is deactivated, there won't be any active_selections, so we should treat cache as invalid in that case.

Another corner case for your list:

A .pot file update that doesn't update the .po files. We should invalidate any cached .po file for that template so translators have a chance to get new untranslated strings.

Ok, I've confirmed this is fixed on edge, and since this is stopping translators from doing their work (i.e. exporting incorrect data), I'd like this cherry-picked.

Should be fixed now on production.