CTAN sync 202106020304

1 files changed, 122 insertions, 57 deletions

diff --git a/macros/latex/base/ltfiles.dtx b/macros/latex/base/ltfiles.dtx
index 99be77c844..bcaac58220 100644
--- a/macros/latex/base/ltfiles.dtx
+++ b/macros/latex/base/ltfiles.dtx
@@ -1,7 +1,7 @@
 % \iffalse meta-comment
 %
-% Copyright (C) 1993-2020
-% The LaTeX3 Project and any individual authors listed elsewhere
+% Copyright (C) 1993-2021
+% The LaTeX Project and any individual authors listed elsewhere
 % in this file.
 %
 % This file is part of the LaTeX base system.
@@ -32,7 +32,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltfiles.dtx}
-             [2020/10/04 v1.2j LaTeX Kernel (File Handling)]
+             [2021/04/17 v1.2m LaTeX Kernel (File Handling)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltfiles.dtx}
@@ -49,6 +49,9 @@
 
 \providecommand\pkg[1]{\texttt{#1}}
 
+\providecommand\InternalDetectionOff{}
+\providecommand\InternalDetectionOn{}
+
 \begin{document}
  \MaintainedByLaTeXTeam{latex}
  \maketitle
@@ -192,19 +195,6 @@
 % \end{oldcomments}
 %
 %
-% \task{???}{Do we use @unused or mainaux?}
-%  \begin{macro}{\@inputcheck}
-%  \begin{macro}{\@unused}
-%    Allocate read stream for testing and output stream.
-% \changes{v1.0l}{1994/11/07}
-%      {move here from ltdefns, remove duplicate \cs{@mainaux}}
-%    \begin{macrocode}
-\newread\@inputcheck
-\newwrite\@unused
-%    \end{macrocode}
-%  \end{macro}
-%  \end{macro}
-%
 % \begin{macro}{\@mainaux}
 % \begin{macro}{\@partaux}
 %    \begin{macrocode}
@@ -334,7 +324,7 @@
 % locally in the output routine. In particular it allows hyphenation
 % in the page head even if the page break happens in verbatim.
 % If this has already been set by a package, set to the value of |\language|
-% at this spoint.
+% at this point.
 % \changes{v1.1n}{2017/03/10}{Save language default}
 %    \begin{macrocode}
   \ifx\document@default@language\m@ne
@@ -456,18 +446,25 @@
 %    harmless), however, in more complicated scenarios where several
 %    full documents are combined to a single document it might get
 %    applied several times with harmful effects. We therefore
-%    explicitly drop it at this point. the coing is somewhat obscure
+%    explicitly drop it at this point. the coding is somewhat obscure
 %    due to the name of the macro which requires constructing.
+% \InternalDetectionOff
 %    \begin{macrocode}
 \edef \@kernel@after@begindocument@before {%
   \let\expandafter\noexpand\csname
        __hook env/document/begin\endcsname
   \noexpand\@empty}
 %    \end{macrocode}
+% \InternalDetectionOn
 %
+%    These internal hooks are already declared earlier (in
+%    \texttt{ltexpl}) so that other modules could write to them.
+% \changes{v1.2m}{2021/04/17}{Move \cs{@kernel@before@begindocument} and
+%  \cs{@kernel@after@begindocument} init earlier so that other modules can
+%    write to the hooks}
 %    \begin{macrocode}
-\let \@kernel@before@begindocument \@empty
-\let \@kernel@after@begindocument \@empty
+%\let \@kernel@before@begindocument \@empty
+%\let \@kernel@after@begindocument  \@empty
 %    \end{macrocode}
 %    
 %  \end{macro}
@@ -710,15 +707,15 @@
     \@latex@error{\string\include\space cannot be nested}\@eha
   \else
 %    \end{macrocode}
-%    Here the normalisation will add |.tex| for all files, (it uses the
-%    the same normalisation as the hooks), so we need to remove that
+%    Here the normalization will add |.tex| for all files, (it uses
+%    the same normalization as the hooks), so we need to remove that
 %    manually.  \cs{@strip@tex@ext} does that.
 %    \begin{macrocode}
     \set@curr@file{#1}%
     \edef\@curr@file{\@strip@tex@ext\@curr@file}%
 %    \end{macrocode}
 %    For historical reasons \cs{@include} expects an argument
-%    delimited by a space. This is kept (though uncessary now) to avoid
+%    delimited by a space. This is kept (though unnecessary now) to avoid
 %    errors in other packages that use \cs{@include} directly.
 %    \begin{macrocode}
     \expandafter\@include\expandafter{\@curr@file} % deliberate space
@@ -726,13 +723,13 @@
 %    \end{macrocode}
 %
 %    Here in \cs{includeonly} we also need to strip |.tex| after
-%    normalisation:
+%    normalization:
 %    \begin{macrocode}
 \def\includeonly#1{%
   \@partswtrue
 %    \end{macrocode}
 %    Because the argument to |\includeonly| is a comma-separated list
-%    of filenames where there may be comma's precedeing some of the
+%    of filenames where there may be comma's preceding some of the
 %    filenames or trailing them. Therefore we need to take the list
 %    apart, remove the unwanted spaces while leaving the spaces
 %    \emph{in} the filenames intact.
@@ -996,10 +993,11 @@
 %   A side effect of the new code is that we will see quotes around
 %   file name displays where there haven't been any before.
 %
-%   For compatibilty with existing code using |{abc}.tex| or |{one.two}.png|
-%   an initial brace group is discarded before expansion and |\string| is applied
-%   The content of the brace group is discarded. This means that a leading space
-%   will be lost unless protected (by |{ }| or |" "| or |\space|) but filenames
+%   For compatibility with existing code using |{abc}.tex| or
+%   |{one.two}.png|, an initial brace group is discarded before
+%   expansion and |\string| is applied.  The content of the brace
+%   group is discarded. This means that a leading space will be lost
+%   unless protected (by |{ }| or |" "| or |\space|) but filenames
 %   with a space are hopefully rare.
 %
 %  \changes{v1.2a}{2019/07/01}{Support UTF-8}
@@ -1058,7 +1056,7 @@
 %
 % \changes{v1.2a}{2019/07/01}{Support UTF-8}
 % \changes{v1.2b}{2019/08/27}{Make command robust}
-% \changes{v1.2d}{2019/10/26}{dont quote name}
+% \changes{v1.2d}{2019/10/26}{don't quote name}
 %    \begin{macrocode}
 \DeclareRobustCommand\IfFileExists[1]{%
   \set@curr@file{#1}%
@@ -1066,30 +1064,114 @@
 %    \end{macrocode}
 %  \end{macro}
 %
+%    \begin{macrocode}
+%</2ekernel|latexrelease>
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{0000/00/00}%
+%<latexrelease>                 {\quote@name}{Quote file names}%
+%<latexrelease>
+%<latexrelease>\let\quote@name\@undefined
+%<latexrelease>\let\quote@@name\@undefined
+%<latexrelease>\let\unquote@name\@undefined
+%<latexrelease>
+%<latexrelease>\long\def \IfFileExists#1#2#3{%
+%<latexrelease>  \openin\@inputcheck#1 %
+%<latexrelease>  \ifeof\@inputcheck
+%<latexrelease>    \ifx\input@path\@undefined
+%<latexrelease>      \def\reserved@a{#3}%
+%<latexrelease>    \else
+%<latexrelease>      \def\reserved@a{\@iffileonpath{#1}{#2}{#3}}%
+%<latexrelease>    \fi
+%<latexrelease>  \else
+%<latexrelease>    \closein\@inputcheck
+%<latexrelease>    \edef\@filef@und{#1 }%
+%<latexrelease>    \def\reserved@a{#2}%
+%<latexrelease>  \fi
+%<latexrelease>  \reserved@a}
+%<latexrelease>
+%<latexrelease>\EndIncludeInRelease
+%<*2ekernel>
+%    \end{macrocode}
+%
+%
+%
 % \begin{macro}{\IfFileExists@}
 % \changes{v0.9b}{1993/12/04}{Macro added}
 % \changes{v0.9p}{1994/01/18}{New Definition}
 % \changes{v1.0t}{1995/05/25}{(CAR) added \cs{long}}
-% \changes{v1.2d}{2019/10/26}{quote on openin}%
+% \changes{v1.2d}{2019/10/26}{quote on openin}
+% \changes{v1.2k}{2021/03/12}{Allow unbalanced conditionals (gh/530)}
 % Argument |#1| is |\@curr@file| so catcode 12 string with no quotes.
+%
+%    The original definition picked up arguments |#2| and |#3| in a
+%    way that they couldn't contain unbalanced conditionals. A better
+%    implementation would have been not to pick up the arguments at
+%    all but instead use the usual \cs{@firstoftwo} and
+%    \cs{secondoftwo}. However, that changes how |#| is interpreted
+%    and so we can't do that nowaways without invalidating a lot of
+%    code. Therefore the somewhat curious construction near the end.
 %    \begin{macrocode}
+%</2ekernel>
+%<*2ekernel|latexrelease>
+%<latexrelease>\IncludeInRelease{2021/06/01}%
+%<latexrelease>                 {\IfFileExists@}{manage unbalanced conditionals}
 \long\def \IfFileExists@#1#2#3{%
   \openin\@inputcheck"#1" %
   \ifeof\@inputcheck
     \ifx\input@path\@undefined
-      \def\reserved@a{#3}%
+      \let\reserved@a\@secondoftwo
     \else
-      \def\reserved@a{\@iffileonpath{#1}{#2}{#3}}%
+      \def\reserved@a{\@iffileonpath{#1}}%
     \fi
   \else
     \closein\@inputcheck
     \edef\@filef@und{"#1" }%
-    \def\reserved@a{#2}%
+    \let\reserved@a\@firstoftwo
   \fi
-  \reserved@a}
+%    \end{macrocode}
+%    This is just there so that any |#| inside |#2| or |#3| needs
+%    doubling (as that was the case in the past).
+%    \begin{macrocode}
+  \expandafter\def\expandafter\reserved@a
+    \expandafter{\reserved@a{#2}{#3}}%
+\reserved@a}
+%</2ekernel|latexrelease>
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{2019/10/01}%
+%<latexrelease>                 {\IfFileExists@}{manage unbalanced conditionals}
+%<latexrelease>
+%<latexrelease>\long\def \IfFileExists@#1#2#3{%
+%<latexrelease>  \openin\@inputcheck"#1" %
+%<latexrelease>  \ifeof\@inputcheck
+%<latexrelease>    \ifx\input@path\@undefined
+%<latexrelease>      \def\reserved@a{#3}%
+%<latexrelease>    \else
+%<latexrelease>      \def\reserved@a{\@iffileonpath{#1}{#2}{#3}}%
+%<latexrelease>    \fi
+%<latexrelease>  \else
+%<latexrelease>    \closein\@inputcheck
+%<latexrelease>    \edef\@filef@und{"#1" }%
+%<latexrelease>    \def\reserved@a{#2}%
+%<latexrelease>  \fi
+%<latexrelease>  \reserved@a}
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{0000/00/00}%
+%<latexrelease>                 {\IfFileExists@}{manage unbalanced conditionals}
+%<latexrelease>
+%<latexrelease>\let\IfFileExists@\@undefined
+%<latexrelease>
+%<latexrelease>
+%<latexrelease>\EndIncludeInRelease
+%<*2ekernel>
 %    \end{macrocode}
 %  \end{macro}
 %
+%
+%
+%
+%
+%
+%
 % \begin{macro}{\@iffileonpath}
 % If the file is not found by |\openin|, and |\input@path| is defined,
 % look in all the directories specified in |\input@path|.
@@ -1103,6 +1185,10 @@
 % \changes{v1.2d}{2019/10/26}{quote on openin}%
 % \changes{v1.2f}{2019/11/11}{make \cs{@filef@und} match quoting used on \cs{openin}}%
 %    \begin{macrocode}
+%</2ekernel>
+%<*2ekernel|latexrelease>
+%<latexrelease>\IncludeInRelease{2019/10/01}%
+%<latexrelease>                 {\@iffileonpath}{Quote file names}
 \long\def\@iffileonpath#1{%
   \let\reserved@a\@secondoftwo
   \expandafter\@tfor\expandafter\reserved@b\expandafter
@@ -1122,28 +1208,7 @@
 %</2ekernel|latexrelease>
 %<latexrelease>\EndIncludeInRelease
 %<latexrelease>\IncludeInRelease{0000/00/00}%
-%<latexrelease>                 {\quote@name}{Quote file names}%
-%<latexrelease>
-%<latexrelease>\let\quote@name\@undefined
-%<latexrelease>\let\quote@@name\@undefined
-%<latexrelease>\let\unquote@name\@undefined
-%<latexrelease>
-%<latexrelease>\let\IfFileExists@\@undefined
-%<latexrelease>
-%<latexrelease>\long\def \IfFileExists#1#2#3{%
-%<latexrelease>  \openin\@inputcheck#1 %
-%<latexrelease>  \ifeof\@inputcheck
-%<latexrelease>    \ifx\input@path\@undefined
-%<latexrelease>      \def\reserved@a{#3}%
-%<latexrelease>    \else
-%<latexrelease>      \def\reserved@a{\@iffileonpath{#1}{#2}{#3}}%
-%<latexrelease>    \fi
-%<latexrelease>  \else
-%<latexrelease>    \closein\@inputcheck
-%<latexrelease>    \edef\@filef@und{#1 }%
-%<latexrelease>    \def\reserved@a{#2}%
-%<latexrelease>  \fi
-%<latexrelease>  \reserved@a}
+%<latexrelease>                 {\quote@name}{Quote file names}
 %<latexrelease>
 %<latexrelease>\long\def\@iffileonpath#1{%
 %<latexrelease>  \let\reserved@a\@secondoftwo