Problem when using \nocite together with the standalone package

Question

Given:

\documentclass{minimal}
\usepackage{standalone}
\begin{document}
\input{inclusion}
\nocite{*}
\bibliographystyle{plain}
\bibliography{test}
\end{document}

With:

\documentclass{minimal}
\begin{document}
Hello World!
\end{document}

And:

@book{Bateman.1906,
 author = {Bateman, Newton and Selby, Paul and Short, William F.},
 year = {1906},
 title = {Historical encyclopedia of Illinois},
 address = {Chicago},
 publisher = {Munsell Pub. Co.}
}


@book{Beckett.1966,
 author = {Beckett, J. C.},
 year = {1966},
 title = {The making of modern Ireland, 1603-1623},
 address = {London},
 publisher = {Faber}
}

I get the following error:

! LaTeX Error: Cannot be used in preamble.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...

l.5 \nocite{*}
?

Yet if I comment out either \input{inclusion} or \nocite{*} the test compiles without error. I'm running a command line of latexmk -xelatex test on Win7 Ultimate. TeX courtesy of MikTeX.

So either I'm doing something egregious or there is something wrong with standalone? Suggestions and brickbats welcome.

Answer 1

This is due to how \nocite is defined:

% latex.ltx, line 6146:
\def\nocite#1{\@bsphack
  \ifx\@onlypreamble\document
    \@for\@citeb:=#1\do{%
      \edef\@citeb{\expandafter\@firstofone\@citeb}%
      \if@filesw\immediate\write\@auxout{\string\citation{\@citeb}}\fi
      \@ifundefined{b@\@citeb}{\G@refundefinedtrue
          \@latex@warning{Citation `\@citeb' undefined}}{}}%
  \else
    \@latex@error{Cannot be used in preamble}\@eha
    % \AtBeginDocument{\nocite{#1}}
  \fi
  \@esphack}

and the fact that standalone redefines \document to be the same as \sa@document, which is reasonable from the point of view of this package, but has the effect of breaking \nocite because the

\ifx\@onlypreamble\document

test will return false.

You can fix the problem by providing a test free version of \nocite at begin document:

\documentclass{article}
\usepackage{standalone}

\makeatletter
\def\@documentnocite#1{\@bsphack
  \@for\@citeb:=#1\do{%
    \edef\@citeb{\expandafter\@firstofone\@citeb}%
    \if@filesw\immediate\write\@auxout{\string\citation{\@citeb}}\fi
    \@ifundefined{b@\@citeb}{\G@refundefinedtrue
      \@latex@warning{Citation `\@citeb' undefined}}{}}%
  \@esphack}
\AtBeginDocument{\let\nocite\@documentnocite}
\makeatother

\begin{document}
\nocite{*}
\input{myersinput}
\nocite{*}
\bibliographystyle{plain}
\bibliography{myersbib}
\end{document}

A simpler code uses etoolbox:

\documentclass{article}
\usepackage{standalone}

\usepackage{etoolbox}
\makeatletter
\AtBeginDocument{
  \patchcmd{\nocite}
    {\ifx\@onlypreamble\document}
    {\iftrue}
    {}
    {\@latex@warning@no@line{\string\nocite\space changed, no patch possible}}
}
\makeatother

\begin{document}
\input{myersinput}
\nocite{*}
\bibliographystyle{plain}
\bibliography{myersbib}
\end{document}