\DocumentMetadata{}
\input regression-test.tex
\documentclass{ltx-talk}
\usepackage{ltxtalk-theme-magpie}
\usepackage{ltxtalk-theme-minimal}

\title[T]{Titled block wrapper}
\author[A]{A}
\date{}

\begin{document}
\useltxtalktheme{magpie}

\begin{frame}
  \frametitle{Titled}
  \begin{block}{Bar title}
    Titled body.
  \end{block}
  \begin{block}<2->{Hidden on slide 1}
    Overlay-gated body.
  \end{block}
\end{frame}

% Switching themes resets the block to the lttheme default (the framed
% "card" look), not to magpie's title bar.
\useltxtalktheme{minimal}
\begin{frame}
  \frametitle{Card again}
  \begin{block}{Card title}
    Card body.
  \end{block}
\end{frame}

\START
\ExplSyntaxOn
% The default "card" uses the plain layout, so the block is not titled
% in the \OsgIfBlockTitledTF sense; the clear undid magpie's title bar.
\OsgIfBlockTitledTF { block }
  { \TYPE { block-titled-after-minimal:FAILED } }
  { \TYPE { block-titled-after-minimal:passed } }

% Re-activate magpie: still titled.
\useltxtalktheme { magpie }
\OsgIfBlockTitledTF { block }
  { \TYPE { block-titled-after-magpie:passed } }
  { \TYPE { block-titled-after-magpie:FAILED } }
\ExplSyntaxOff
\END
\end{document}