guard star in counterwithin/out, from review #1632

base/ltcounts.dtx

@@ -116,7 +116,8 @@
 % |\the|\meta{within-counter}.\meta{format}\marg{counter} with \cs{arabic} as
 % the default for \meta{format}.
 % Star form omits redefining the print representation.
-
+%
+% The |*| alias for the current counter may not be used in either argument.
 %
 % \DescribeMacro\counterwithout
 % |\counterwithout|\oarg{format}\marg{counter}\marg{within-counter}:
@@ -127,6 +128,8 @@
 % the default for \meta{format}.
 % Star form omits redefining the print representation.
 %
+% The |*| alias for the current counter may not be used in either argument.
+%
 % \MaybeStop{}
 %
 %    \begin{macrocode}
@@ -260,7 +263,7 @@
   \def\csname c@*\endcsname{\value\@currentcounter}
 %    \end{macrocode}
 % \end{macro}
-
+%
 %\begin{macro}{\@newctr}
 % \changes{v1.0d}{1994/04/09}
 %     {\cs{@nocnterr} now has counter name argument}
@@ -437,19 +440,27 @@
     \endgroup}}
 %    \end{macrocode}
 %  \end{macro}
-
-
-
+%
 %  \begin{macro}{\@ifbothcounters}
 %    \changes{v1.1k}{2018/03/08}{Interface added}
+%    \changes{v1.2a}{2025/01/22}{Guard against star alias.}
 %    Test if arg |#1| and |#2| are counters and if so execute |#3|.
 %    \begin{macrocode}
+\begingroup\catcode`\*=11 \lowercase{\endgroup
 \def\@ifbothcounters#1#2#3{%
+%    \end{macrocode}
+%    \begin{macrocode}
+  \begingroup\let\c@*\@undefined
+%    \end{macrocode}
+%    \begin{macrocode}
   \@ifundefined{c@#1}{\@nocounterr{#1}}%
     {% else counter is defined
      \@ifundefined{c@#2}{\@nocounterr{#2}}%
        {% else both counter and within  are defined
-        #3}}}
+         #3}}%
+%    \end{macrocode}
+%    \begin{macrocode}
+   \endgroup}}
 %    \end{macrocode}
 %  \end{macro}
 %
@@ -636,7 +647,7 @@
 %     |\@Roman\FOOcounter|
 %     Representation of |\FOOcounter| as upper-case
 %                    Roman numerals.
-
+%
 % \changes{v1.1f}{1997/10/06}{Change \cs{@Roman} to be fully
 %    expandable, so that the result is written properly to files.}
 %    \begin{macrocode}