[latex3-commits] [latex3/latex2e] gh1460: bit more code documentation (7dc1e471)

[github at latex-project.org]

Repository : https://github.com/latex3/latex2e
On branch  : gh1460
Link       : https://github.com/latex3/latex2e/commit/7dc1e471f5f66752c8fd99d4d03df2ea7ed51dc8

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

commit 7dc1e471f5f66752c8fd99d4d03df2ea7ed51dc8
Author: Frank Mittelbach <frank.mittelbach at latex-project.org>
Date:   Tue Sep 10 23:11:31 2024 +0200

    bit more code documentation


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

7dc1e471f5f66752c8fd99d4d03df2ea7ed51dc8
 base/changes.txt |  1 +
 base/ltspace.dtx | 30 +++++++++++-------------------
 2 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/base/changes.txt b/base/changes.txt
index 30e6d2d0..46cc6f9a 100644
--- a/base/changes.txt
+++ b/base/changes.txt
@@ -11,6 +11,7 @@ not part of the distribution.
 	* ltspace.dtx (subsection{Vertical spacing}):
 	Drop unnecessary \@noitemerr in \addvspace and \addpenalty and
 	instead generate \@parmodeerr if we are in restricted hmode (gh/1460)
+	Also use \protected definitions for them.
 
 2024-09-03 Ulrike Fischer <Ulrike.Fischer at latex-project.org>
 	* fontdef.dtx: preload t1cmss.fd and t1cmtt.fd
diff --git a/base/ltspace.dtx b/base/ltspace.dtx
index d55b36db..774357e4 100644
--- a/base/ltspace.dtx
+++ b/base/ltspace.dtx
@@ -833,25 +833,6 @@
 % heading commands to inhibit page breaking after a heading.)
 %
 %
-%\begin{verbatim}
-% \addvspace{SKIP} ==
-%  BEGIN
-%   if vmode
-%     then if @minipage
-%            else if \lastskip =0
-%                    then  \vskip SKIP
-%                    else  if \lastskip < SKIP
-%                             then  \vskip -\lastskip
-%                                   \vskip SKIP
-%                             else if SKIP < 0 and \lastskip >= 0
-%                                    then \vskip -\lastskip
-%                                         \vskip \lastskip + SKIP
-%          fi      fi       fi      fi
-%     else useful error message (CAR).
-%   fi
-%  END
-%\end{verbatim}
-%
 % \begin{macro}{\@xaddvskip}
 % Internal macro for |\vspace| handling the case that space has
 % previously been added.
@@ -888,6 +869,13 @@
 %<latexrelease>\IncludeInRelease{2024/11/01}%
 %<latexrelease>                 {\addvspace}{drop unnecessary no-item error}%
 \protected\def\addvspace#1{%
+%    \end{macrocode}
+%    If encounter in hmode we check if we are in an hbox and if so
+%    generate a \LaTeX{} error, as otherwise this would cause a bunch
+%    of low-level errors. In unrestricted hmode we simply switch to vmode by
+%    issuing a \cs{par}.
+%    would 
+%    \begin{macrocode}
   \ifhmode \ifinner \@parmoderr \else \par \fi \fi
 %    \end{macrocode}
 %    
@@ -960,6 +948,10 @@
 %    \end{macrocode}
 %    \begin{macrocode}
 \protected\def\addpenalty#1{%
+%    \end{macrocode}
+%    See documentation of \cs{addvspace} for documentation of the next
+%    line of code.
+%    \begin{macrocode}
   \ifhmode \ifinner \@parmoderr \else \par \fi \fi
 %    \end{macrocode}
 %   Fix provided by Donald (though the original fix was not good