\input regression-test.tex
\documentclass{article}
% "bcp47=false" turns off babel's tag mapping; selection then relies on a
% "map" entry giving the babel language name.  This must keep working.
\usepackage[ngerman,english]{babel}
\usepackage[
  languages={en,de},
  targetlang=de,
  map={de=ngerman,en=english},
  bcp47=false
]{langselect}
\begin{document}
\START
\TYPE{target=\olsTargetLanguage}
\TYPE{active=\languagename}
\lende{English}{Deutsch}
\END
\end{document}