Taxonomy archives return in default language

For example: http://freespeechdebate.com/de/tag/christianity/

All posts returned are in English, the default language. The posts should be in the current language, in this case German. (Note that the permalinks appear to be in the correct language.)

Start by reproducing the German taxonomy archive at http://freespeechdebate.com/de/tag/christianity/ and trace how the archive selects posts and the current language. Done means the archive returns German posts while retaining the existing localized permalink behavior; no source files or tests are named in the report.

Written by the indexing model from the issue text.