[Tex/LaTex] Beamer footcite citation appears twice if used in long caption

beamercaptionscitingfootnotes

I noticed strange behaviour of the \footcite command when used in captions within beamer. In the working example provided the first frame has a \footcite on an itemize item, this works as expected. The second frame has a \footcite in a caption within a table, again this works as expected. The third frame is identical to the second, except it has a caption that spans two lines (a long caption). When the caption is pushed to the next line, as in the case of the third frame, two citations appear at the bottom of the frame when only once is expected. Both these citations are identical, but the footmark increased (in this case #3 is no where to be found, but #4 was present in the caption).

Is there some way around this strange behaviour? I don't really want to cut my citations down so they fit on one line. I am not sure if this is some weird bug or that I am using \footcite inappropriately.

\documentclass{beamer}

\begin{filecontents*}{mybibfile.bib}
@ARTICLE{authora,
  author = {A. Aaaaa},
  title = {Some article},
  journal = {Journal of Dummy Article Names},
  year = {2012},
  volume = {99},
  pages = {1-5}
}

@ARTICLE{authorb,
  author = {B. Baaaa},
  title = {Another article},
  journal = {Journal of Dummy Article Names},
  year = {2012},
  volume = {99},
  pages = {6-10}
}

@ARTICLE{authorbb,
  author = {B. Baaaa},
  title = {Another dup article},
  journal = {Journal of Dummy Article Names},
  year = {2012},
  volume = {99},
  pages = {6-10}
}
\end{filecontents*}

\usepackage[style=verbose-note,autocite=footnote,abbreviate=true,backend=bibtex]{biblatex} 
\addbibresource{mybibfile.bib}

\usetheme{CambridgeUS}

\title{Beamer}
\author{Anyone}

\begin{document}

\begin{frame}
\frametitle{Introduction}
  \begin{itemize}
    \item ItemA~\footcite{authora} %This works
    \item ItemB
  \end{itemize}
\end{frame}

\begin{frame}
\frametitle{Introduction}
  \scriptsize
  \begin{table}[!tb]
    \centering
    \begin{tabular}{|l|l|}
      \hline 1 & 2 \\
      \hline a & b \\
      \hline
    \end{tabular}
    \caption{This only appears once~\footcite{authorb}.}
  \end{table}
\end{frame}

\begin{frame}
\frametitle{Introduction}
  \scriptsize
  \begin{table}[!tb]
    \centering
    \begin{tabular}{|l|l|}
      \hline 1 & 2 \\
      \hline a & b \\
      \hline
    \end{tabular}
    \caption{This only appears twice because the caption spans two lines blah blah blah blah?~\footcite{authorbb}.}
  \end{table}
\end{frame}

\end{document}

Best Answer

Footnotes and footnote citations are problematic inside captions; as a workaround, you can use \footnotemark inside the \caption and \footcitetext{<text>} outside the caption:

\documentclass{beamer}

\begin{filecontents*}{mybibfile.bib}
@ARTICLE{authora,
  author = {A. Aaaaa},
  title = {Some article},
  journal = {Journal of Dummy Article Names},
  year = {2012},
  volume = {99},
  pages = {1-5}
}

@ARTICLE{authorb,
  author = {B. Baaaa},
  title = {Another article},
  journal = {Journal of Dummy Article Names},
  year = {2012},
  volume = {99},
  pages = {6-10}
}

@ARTICLE{authorbb,
  author = {B. Baaaa},
  title = {Another dup article},
  journal = {Journal of Dummy Article Names},
  year = {2012},
  volume = {99},
  pages = {6-10}
}
\end{filecontents*}

\usepackage[style=verbose-note,autocite=footnote,abbreviate=true,backend=bibtex]{biblatex} 
\addbibresource{mybibfile.bib}

\usetheme{CambridgeUS}

\title{Beamer}
\author{Anyone}

\begin{document}

\begin{frame}
\frametitle{Introduction}
  \begin{itemize}
    \item ItemA~\footcite{authora} %This works
    \item ItemB
  \end{itemize}
\end{frame}

\begin{frame}
\frametitle{Introduction}
  \scriptsize
  \begin{table}
    \centering
    \begin{tabular}{|l|l|}
      \hline 1 & 2 \\
      \hline a & b \\
      \hline
    \end{tabular}
    \caption{This only appears once~\footnotemark.}
  \end{table}
\footcitetext{authorb}
\end{frame}

\begin{frame}
\frametitle{Introduction}
  \scriptsize
  \begin{table}
    \centering
    \begin{tabular}{|l|l|}
      \hline 1 & 2 \\
      \hline a & b \\
      \hline
    \end{tabular}
    \caption{This appears once~\footnotemark.}
  \end{table}
\footcitetext{authorbb}
\end{frame}

\end{document}

As a side note, in beamer there's no need to use placement specifiers for floats since beamer internally deactivates the floating mechanism.

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