Strip trailing newline from macro expansion in @example

[Gavin Smith]

Below is the change I plan on making to fix a bug. It manages to strip
the final newline from the macro's body when expanded, regardless if
it's being expanded in a context where CR has the usual meaning (a
space, and multiple blank lines break a paragraph), and a context
where it always ends the line, as in an @example environment. It does
this by testing the catcode of CR with an \ifnum conditional. It
appears to produce good results with the test file I've attached.

Index: texinfo.tex
===================================================================
--- texinfo.tex (revision 6518)
+++ texinfo.tex (working copy)
@@ -7343,6 +7343,11 @@
   }
 \fi

+% Used to remove a category 13 newline, added to the end of the last
+% line read in by \scantokens.
+{\catcode`\^^M=13 \gdef\gobblecr^^M{}}
+
+% Argument is macro body with arguments substituted
 \def\scanmacro#1{\begingroup
   \newlinechar`\^^M
   \let\xeatspaces\eatspaces
@@ -7357,15 +7362,14 @@
   % ... and for \example:
   \spaceisspace
   %
-  % The \empty here causes a following catcode 5 newline to be eaten as
-  % part of reading whitespace after a control sequence.  It does not
-  % eat a catcode 13 newline.  There's no good way to handle the two
-  % cases (untried: maybe e-TeX's \everyeof could help, though plain TeX
-  % would then have different behavior).  See the Macro Details node in
-  % the manual for the workaround we recommend for macros and
-  % line-oriented commands.
-  %
-  \scantokens{#1\empty}%
+  \ifnum\catcode`\^^M=5
+    % The \empty here causes a following catcode 5 newline to be eaten as
+    % part of reading whitespace after a control sequence.
+    \scantokens{#1\empty}%
+  \else
+    \catcode`\^^M=13
+    \scantokens{#1\gobblecr}%
+  \fi
 \endgroup}

stripmacrocr.texi
Description: TeXInfo document