Initially filed by adamwill at https://fedorahosted.org/autoqa/ticket/382

An idea for a new test just came up in the release readiness meeting - an rpmdiff-style check for whether translatable strings have changed in a new package build, which we could use to enforce the string freeze (flag up packages with changed strings after the string freeze).

In vague hand-wavy theory this should just come down to diffing the files flagged with %lang in the package list, I guess?