[latex3-commits] [latex3/latex2e] gh823: possible fix for #823 (56982ed0)

[github at latex-project.org]

Repository : https://github.com/latex3/latex2e
On branch  : gh823
Link       : https://github.com/latex3/latex2e/commit/56982ed0a6172518e1d8002aa03b7ddff22fc66c

>---------------------------------------------------------------

commit 56982ed0a6172518e1d8002aa03b7ddff22fc66c
Author: Frank Mittelbach <frank.mittelbach at latex-project.org>
Date:   Tue Nov 7 18:23:24 2023 +0100

    possible fix for #823


>---------------------------------------------------------------

56982ed0a6172518e1d8002aa03b7ddff22fc66c
 base/changes.txt               |  4 ++++
 base/ltcounts.dtx              | 14 ++++++++++----
 base/testfiles/github-0823.lvt | 32 ++++++++++++++++++++++++++++++++
 base/testfiles/github-0823.tlg |  9 +++++++++
 4 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/base/changes.txt b/base/changes.txt
index 812143d3..e1e3e904 100644
--- a/base/changes.txt
+++ b/base/changes.txt
@@ -6,6 +6,10 @@ to completeness or accuracy and it contains some references to files that are
 not part of the distribution.
 ================================================================================
 
+2023-11-07  Frank Mittelbach  <Frank.Mittelbach at latex-project.org>
+	* ltcounts.dtx (subsection{Environment Counter Macros}):
+	In \newcounter do not change \the... if already defined (gh/823)
+
 ================================================================================
 All changes above are only part of the development branch for the next release.
 ================================================================================
diff --git a/base/ltcounts.dtx b/base/ltcounts.dtx
index 69025fa4..c9dd05c5 100644
--- a/base/ltcounts.dtx
+++ b/base/ltcounts.dtx
@@ -33,7 +33,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltcounts.dtx}
-             [2021/07/08 v1.1m LaTeX Kernel (Counters)]
+             [2021/11/07 v1.1n LaTeX Kernel (Counters)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltcounts.dtx}
@@ -305,6 +305,7 @@
 %  \begin{macro}{\@definecounter}
 %  \changes{v1.1b}{1995/05/20}{Streamlined code}
 %  \changes{v1.1c}{1995/05/20}{And do it right}
+%  \changes{v1.1n}{2023/11/07}{Do not change \cs{the...} if already defined (gh/823)}
 %
 %    \begin{macrocode}
 \def\@definecounter#1{\expandafter\newcount\csname c@#1\endcsname
@@ -312,9 +313,14 @@
      \global\expandafter\let\csname cl@#1\endcsname\@empty
      \@addtoreset{#1}{@ckpt}%
      \global\expandafter\let\csname p@#1\endcsname\@empty
-     \expandafter
-     \gdef\csname the#1\expandafter\endcsname\expandafter
-          {\expandafter\@arabic\csname c@#1\endcsname}}
+     \ifcsname the#1\endcsname
+     \@latex at warning{Command `\string\the#1' already
+                     defined -- not changed}%
+     \else
+       \expandafter
+       \gdef\csname the#1\expandafter\endcsname\expandafter
+              {\expandafter\@arabic\csname c@#1\endcsname}%
+     \fi}
 %    \end{macrocode}
 %  \end{macro}
 %
diff --git a/base/testfiles/github-0823.lvt b/base/testfiles/github-0823.lvt
new file mode 100644
index 00000000..01a4806a
--- /dev/null
+++ b/base/testfiles/github-0823.lvt
@@ -0,0 +1,32 @@
+\documentclass{article}
+
+\input{test2e}
+
+\usepackage{makeidx}
+\makeindex
+
+\START
+
+% bad, but user is not warned
+\newcounter{index}
+\newcounter{bibliography}
+
+\OMIT
+\begin{document}
+\TIMO
+
+test % btw without it nothing goes to idx...
+\index{foobar}
+
+\cite{qqq}
+
+\begin{thebibliography}{99}
+\bibitem{qqq}hmm
+\end{thebibliography}
+
+% lonely \item error
+\printindex
+
+\newpage
+\OMIT
+\end{document}
diff --git a/base/testfiles/github-0823.tlg b/base/testfiles/github-0823.tlg
new file mode 100644
index 00000000..353b7cab
--- /dev/null
+++ b/base/testfiles/github-0823.tlg
@@ -0,0 +1,9 @@
+This is a generated file for the LaTeX2e validation system.
+Don't change this file in any respect.
+\c at index=\count...
+LaTeX Warning: Command `\theindex' already defined -- not changed on input line ....
+\c at bibliography=\count...
+LaTeX Warning: Command `\thebibliography' already defined -- not changed on input line ....
+No file github-0823.ind.
+[1
+]