1 files changed, 65 insertions, 26 deletions
diff --git a/Master/texmf-dist/source/latex/extract/extract.dtx b/Master/texmf-dist/source/latex/extract/extract.dtx
index 42aa96f4c5b..801a9834338 100644
--- a/Master/texmf-dist/source/latex/extract/extract.dtx
+++ b/Master/texmf-dist/source/latex/extract/extract.dtx
@@ -16,7 +16,7 @@
 %    extract.sty
 %
 %% ---------------------------------------
-%% Copyright (C) 2004-2005 Hendri Adriaens
+%% Copyright (C) 2004-2019 Hendri Adriaens
 %% ---------------------------------------
 %%
 %% This work may be distributed and/or modified under the
@@ -109,7 +109,7 @@ of the package.
 %
 % \GetFileInfo{extract.sty}
 %
-% \CheckSum{1011}
+% \CheckSum{1069}
 %
 % \DoNotIndex{\@backslashchar,\@bsphack,\@checkend,\@currenvir,
 % \@currenvline,\@doendpe,\@eha,\@ehc,\@empty,\@endpefalse,\@esphack,
@@ -920,7 +920,7 @@ of the package.
 %<*extract>
 \NeedsTeXFormat{LaTeX2e}[1995/12/01]
 \ProvidesPackage{extract}
-  [2019/09/17 v1.9 extract content from document (HA)]
+  [2019/09/18 v1.9a extract content from document (HA)]
 \RequirePackage{verbatim}
 \RequirePackage{xkeyval}
 \newwrite\XTR@out
@@ -1086,47 +1086,50 @@ of the package.
 % \end{macro}
 % \begin{macro}{\begin}
 % \marg{environment}\\
-% \changes{v1.9}{2019/09/17}{Changed definition to robust version}
+% \changes{v1.9a}{2019/09/18}{Added definitions for robust versions of \cs{begin} and \cs{end}}
 % Modify the macro |\begin| to allow adding code to a level specific
 % hook which can be executed after |\endgroup| in |\end|. See for
-% more info on this macro the \LaTeX\ source~\cite{LaTeXbase}.
-%    \begin{macrocode}
-\@namedef{begin}#1{%
-  \@ifundefined{#1}%
-    {\def\reserved@a{\@latex@error{Environment #1 undefined}\@eha}}%
-    {\def\reserved@a{\def\@currenvir{#1}%
-     \edef\@currenvline{\on@line}%
-     \csname #1\endcsname}}%
-  \@ignorefalse
-  \begingroup\@endpefalse
+% more info on this macro the \LaTeX\ source~\cite{LaTeXbase}. We first do this
+% for the new \LaTeX\ format, which defines robust versions of |\begin| and |\end|.
+%    \begin{macrocode}
+\@ifl@t@r\fmtversion{2019/10/01}%
+{% new format
+  \@namedef{begin }#1{%
+    \@ifundefined{#1}%
+      {\def\reserved@a{\@latex@error{Environment #1 undefined}\@eha}}%
+      {\def\reserved@a{\def\@currenvir{#1}%
+       \edef\@currenvline{\on@line}%
+       \csname #1\endcsname}}%
+    \@ignorefalse
+    \begingroup\@endpefalse
 %    \end{macrocode}
 % Advance depth level.
 %    \begin{macrocode}
-  \global\advance\@envdepth\@ne
+    \global\advance\@envdepth\@ne
 %    \end{macrocode}
 % Initialize the hook for this level.
 %    \begin{macrocode}
-  \global\@namedef{@afterendenvhook@\romannumeral\@envdepth}{}%
-  \reserved@a}
+    \global\@namedef{@afterendenvhook@\romannumeral\@envdepth}{}%
+    \reserved@a
+  }%
 %    \end{macrocode}
 % \end{macro}
 % \begin{macro}{\end}
 % \marg{environment}\\
-% \changes{v1.9}{2019/09/17}{Changed definition to robust version}
 % Modify |\end| to execute the code collected in the hook.
 %    \begin{macrocode}
-\@namedef{end}#1{%
-  \csname end#1\endcsname\@checkend{#1}%
-  \expandafter\endgroup\if@endpe\@doendpe\fi
+  \@namedef{end }#1{%
+    \csname end#1\endcsname\@checkend{#1}%
+    \expandafter\endgroup\if@endpe\@doendpe\fi
 %    \end{macrocode}
 % Copy current hook code to a temporary macro.
 %    \begin{macrocode}
-  \expandafter\let\expandafter\reserved@a
-    \csname @afterendenvhook@\romannumeral\@envdepth\endcsname
+    \expandafter\let\expandafter\reserved@a
+      \csname @afterendenvhook@\romannumeral\@envdepth\endcsname
 %    \end{macrocode}
 % Decrease the depth.
 %    \begin{macrocode}
-  \global\advance\@envdepth\m@ne
+    \global\advance\@envdepth\m@ne
 %    \end{macrocode}
 % Execute the hook of the current environment. This is done after
 % decreasing the depth as to avoid level mixing problems when the
@@ -1135,8 +1138,44 @@ of the package.
 % defined since it is executed after the group and does not belong
 % anymore to the environment in which the hook was defined.
 %    \begin{macrocode}
-  \reserved@a\relax
-  \if@ignore\@ignorefalse\ignorespaces\fi}
+    \reserved@a\relax
+    \if@ignore\@ignorefalse\ignorespaces\fi
+  }%
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\begin}
+% \marg{environment}\\
+% This is the code for the old format of \LaTeX.
+%    \begin{macrocode}
+}{% old format
+  \def\begin#1{%
+    \@ifundefined{#1}%
+      {\def\reserved@a{\@latex@error{Environment #1 undefined}\@eha}}%
+      {\def\reserved@a{\def\@currenvir{#1}%
+       \edef\@currenvline{\on@line}%
+       \csname #1\endcsname}}%
+    \@ignorefalse
+    \begingroup\@endpefalse
+    \global\advance\@envdepth\@ne
+    \global\@namedef{@afterendenvhook@\romannumeral\@envdepth}{}%
+    \reserved@a
+  }%
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\end}
+% \marg{environment}
+% This is the code for the old format of \LaTeX.
+%    \begin{macrocode}
+  \def\end#1{%
+    \csname end#1\endcsname\@checkend{#1}%
+    \expandafter\endgroup\if@endpe\@doendpe\fi
+    \expandafter\let\expandafter\reserved@a
+      \csname @afterendenvhook@\romannumeral\@envdepth\endcsname
+    \global\advance\@envdepth\m@ne
+    \reserved@a\relax
+    \if@ignore\@ignorefalse\ignorespaces\fi
+  }%
+}
 %    \end{macrocode}
 % \end{macro}
 % \begin{macro}{\AfterEndEnv}