preview patch in pgfutil-latex.def breaks with the next latex

[u-fischer]

Brief outline of the bug

pgf patches preview in pgfutil-latex.def. The patch uses everyshi commands which are no longer present in the next latex, which emulates everyshi.

Minimal working example (MWE)

\documentclass{article}
\RequirePackage[active]{preview}
\usepackage{pgf}
\begin{document}
abc
\end{document}

errors with

! Undefined control sequence.
\@outputpage ...istfalse \@parboxrestore \shipout 
                                                  \vbox {\set@typeset@protec...
l.23 \end{document}

Using the preview environment gives similar errors.

Disabling this patch in pgfutil-latex-def avoids the errors:

% Preview hack: preview.sty hacks into \shipout (which is ok), but
% does not honour everyshi.sty (which is not ok). This causes everyshi
% material to get lost.
\AtBeginDocument{
    \@ifpackageloaded{preview}{%
        % Ok, package loaded. Swap definitions of everyshi.sty's shipout
        % and preview.sty's shipout:
        \ifPreview
            \let\shipout\@EveryShipout@Org@Shipout%This is the null version of \shipout, created by preview and saved by everyshi
            \let\@EveryShipout@Org@Shipout\pr@shipout% This is the original shipout
            \let\pr@shipout\@EveryShipout@Shipout%
        \fi
        }{}%
}

But I don't know what the patch tried to do, and have no means to check if a replacement is needed or if it can simply be dropped in a new latex.