Onslide on a frame with itemize in notes produces too many slides

[Delzye]

Minimal Example:

\begin{frame}
    \onslide*<1>{1}
    \onslide*<2>{2}
    \note{
        \begin{itemize}
            \item<1> 1
            \item<2> 2
        \end{itemize}
    }
\end{frame}

Problem: I would expect this code to produce two slides, the first has a "1" on the slide and an item in the notes with a "1" and the same with a "2" for the second slide. But it produces three slides where the third has no content, but the note has an item with a "2" on it.

My result:

The workaround is quite easy with a <1-2> after \begin{frame}, but it still should not be happening.

Or am I missing something/doing something wrong?

[samcarter]

As a workaround, you could use

\documentclass{beamer}

\setbeameroption{show notes on second screen}

\makeatletter
\patchcmd{\beamer@setupnote}{\begin{enumerate}}{\begin{itemize}}{}{}
\patchcmd{\beamer@setupnote}{\end{enumerate}}{\end{itemize}}{}{}
\makeatother

\begin{document}
	
\begin{frame}
    \only<1>{1}
    \only<2>{2}
    \note[item]<1>{1}
    \note[item]<2>{2}
\end{frame}

\end{document}

[samcarter]

Note to self:

Minimal reproducible example

\documentclass{beamer}

\setbeameroption{show notes on second screen}

\begin{document}
	
\begin{frame}
    \only<2>{2}
    \note{
      \only<2>{2}
    }
\end{frame}

\end{document}

[samcarter]

This problem started somewhere between TL17 and TL18

[samcarter]

The problem seems to have started in a5b601498b51f2a17b327e230e928293349ebf7d

[samcarter]

This seems to work, but I don't know why this decreasing/increasing of the counter was added in the first place

\documentclass{beamer}

%\setbeameroption{show notes}
\setbeameroption{show notes on second screen=right}
%\setbeameroption{show only notes} 

\makeatletter
\def\beamer@setupnote{%
  \gdef\beamer@notesactions{%
    \beamer@outsideframenote{%
      % Notice that the note page is typeset at the beginning of the next slide
%      \advance\beamer@slideinframe by-1\relax
      \beamer@atbeginnote%
      \beamer@notes%
      \ifx\beamer@noteitems\@empty\else
      \begin{enumerate}\itemsep=0pt\parskip=0pt%
        \beamer@noteitems%
      \end{enumerate}%
      \fi%
      \beamer@atendnote%
%      \advance\beamer@slideinframe by 1\relax%
    }%
    \gdef\beamer@notesactions{}%
  }
}
\makeatother

\begin{document}
	
\begin{frame}
    \only<2>{2}
    \note{
      \only<2>{2}
    }
\end{frame}

\end{document}

[josephwright]

@samcarter It was to fix https://github.com/josephwright/beamer/issues/324, which I vaguely remember and I am reasonably sure was an issue at the time

[samcarter]

@josephwright so we probably have to distinguish between the cases where only notes are shown and where notes are shown together with the slides