Beamer handout mode and againframe bug?

Question

So here is some puzzling behaviour.

\documentclass[
handout
]{beamer}

\begin{document}
\begin{frame}<1>[label=foo]
  \begin{itemize}[<+->]
  \item One
  \item Two
  \end{itemize}
\end{frame}

\frame{Aside}

\againframe{foo}
\end{document}

As you can see, the first handout page is the second slide of the first frame, whereas I'd like it to be the first slide (i.e. the slide without the "two").

To be clear, the expected (and desired) behaviour for the handout is that there are three pages: One, then Aside, then One/Two.

Putting handout:1 in the slide specification of the frame doesn't help.

Is this a bug? Or is the beamer slide specification more mysterious than I think?

Answer 1

Your code is equivalent to the following

\documentclass[handout]{beamer}
\begin{document}
\begin{frame}<beamer:1>[label=foo]
  \begin{itemize}[<beamer:+->]
  \item One
  \item Two
  \end{itemize}
\end{frame}
\frame{Aside}
\againframe{foo}
\end{document}

That is, all overlay specifications are only meaningful in beamer mode.

When you pass handout to be the current mode, Beamer only recognizes the specifications begun with handout:. As a result, all specification in your code, those begun with beamer:, are ignored. That is, everything happens like there are no < and > at all.

Therefore it is not a issue that Beamer should insert which slide into handout. In fact, there is one and only one slide for each frame.

To make it possible to control overlay specification in handout mode, you need to pass specifications begun with handout:. Well... there is an easier way: begin all specification with all:.

\documentclass[handout]{beamer}
\begin{document}
\begin{frame}<handout:1>[label=foo]
  \begin{itemize}[<all:+->]
  \item One
  \item Two
  \end{itemize}
\end{frame}
\frame{Aside}
\againframe<all:2>{foo}
\end{document}