1 files changed, 42 insertions, 5 deletions
diff --git a/macros/latex/base/ltboxes.dtx b/macros/latex/base/ltboxes.dtx
index 61ea87235a..39c134b3bf 100644
--- a/macros/latex/base/ltboxes.dtx
+++ b/macros/latex/base/ltboxes.dtx
@@ -33,7 +33,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltboxes.dtx}
-             [2019/08/27 v1.3b LaTeX Kernel (Box Commands)]
+             [2020/09/27 v1.4a LaTeX Kernel (Box Commands)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltboxes.dtx}
@@ -365,8 +365,13 @@
 % \begin{macro}{\@imakepicbox}
 % picture mode version
 %    \begin{macrocode}
+%</2ekernel>
+%<*2ekernel|latexrelease>
+%<latexrelease>\IncludeInRelease{2020/10/01}%
+%<latexrelease>                 {\@imakepicbox}{default units}%
 \long\def\@imakepicbox(#1,#2)[#3]#4{%
-  \vbox to#2\unitlength
+  \@defaultunitsset\@tempdimc{#2}\unitlength
+  \vbox to\@tempdimc
    {\let\mb@b\vss \let\mb@l\hss\let\mb@r\hss
     \let\mb@t\vss
     \@tfor\reserved@a :=#3\do{%
@@ -376,14 +381,38 @@
         \expandafter\let\csname mb@\reserved@a\endcsname\relax
       \fi}%
     \mb@t
-    \hb@xt@ #1\unitlength{\mb@l #4\mb@r}%
+    \@defaultunitsset\@tempdimc{#1}\unitlength
+    \hb@xt@\@tempdimc{\mb@l #4\mb@r}%
     \mb@b
 %    \end{macrocode}
 % This kern ensures that a |b| option aligns on the bottom of the
 % text rather than the baseline. this is the documented behaviour in
-% the \LaTeX Book. The kern is removed in compatibility mode.
+% the \LaTeX\ Book. The kern is removed in compatibility mode.
 %    \begin{macrocode}
     \kern\z@}}
+%</2ekernel|latexrelease>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{0000/00/00}%
+%<latexrelease>                 {\@imakepicbox}{default units}%
+%<latexrelease>\long\def\@imakepicbox(#1,#2)[#3]#4{%
+%<latexrelease>  \vbox to#2\unitlength
+%<latexrelease>   {\let\mb@b\vss \let\mb@l\hss\let\mb@r\hss
+%<latexrelease>    \let\mb@t\vss
+%<latexrelease>    \@tfor\reserved@a :=#3\do{%
+%<latexrelease>      \if s\reserved@a
+%<latexrelease>        \let\mb@l\relax\let\mb@r\relax
+%<latexrelease>      \else
+%<latexrelease>        \expandafter\let\csname mb@\reserved@a\endcsname\relax
+%<latexrelease>      \fi}%
+%<latexrelease>    \mb@t
+%<latexrelease>    \hb@xt@ #1\unitlength{\mb@l #4\mb@r}%
+%<latexrelease>    \mb@b
+%<latexrelease>    \kern\z@}}
+%<latexrelease>\EndIncludeInRelease
+%<*2ekernel>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1290,13 +1319,21 @@
 %
 %  \begin{macro}{\rlap}
 %  \begin{macro}{\llap}
+%  \begin{macro}{\clap}
 %    These macros place text to the left or right of the current
 %    reference point without taking up space.
-%  \end{macro}
 %    \begin{macrocode}
 \DeclareRobustCommand\rlap[1]{\hb@xt@\z@{#1\hss}}
 \DeclareRobustCommand\llap[1]{\hb@xt@\z@{\hss#1}}
 %    \end{macrocode}
+%    And here is the version that centers, it was initially introduced by
+%    \texttt{mathtools}.
+% \changes{v1.3c}{2020/03/06}{Macro \cs{clap} added}
+%    \begin{macrocode}
+\DeclareRobustCommand\clap[1]{\hb@xt@\z@{\hss#1\hss}}
+%    \end{macrocode}
+%  \end{macro}
+%  \end{macro}
 %  \end{macro}
 %
 %    \begin{macrocode}