CTAN sync 202106300303

4 files changed, 212 insertions, 85 deletions

diff --git a/macros/latex/contrib/lwarp/README.txt b/macros/latex/contrib/lwarp/README.txt
index 3c6e60f99a..f89d6b4dd8 100644
--- a/macros/latex/contrib/lwarp/README.txt
+++ b/macros/latex/contrib/lwarp/README.txt
@@ -1,5 +1,5 @@
 
-LaTeX lwarp package v0.898   README.txt
+LaTeX lwarp package v0.899   README.txt
 
 Files included are:
 
diff --git a/macros/latex/contrib/lwarp/lwarp.dtx b/macros/latex/contrib/lwarp/lwarp.dtx
index 0692faa1a3..54b4857907 100644
--- a/macros/latex/contrib/lwarp/lwarp.dtx
+++ b/macros/latex/contrib/lwarp/lwarp.dtx
@@ -16,7 +16,7 @@
 % \iffalse
 %<package>\NeedsTeXFormat{LaTeX2e}[1999/12/01]
 %<package>\ProvidesPackage{lwarp}
-%<package>    [2021/05/24 v0.898  Allows LaTeX to directly produce HTML5 output.]
+%<package>    [2021/06/29 v0.899  Allows LaTeX to directly produce HTML5 output.]
 %
 %<*driver>
 \documentclass{ltxdoc}
@@ -2828,6 +2828,8 @@ use an absolute width for
 \cs{keyfig}, instead of \optn{lw}-proportional widths.
 (The \optn{[H]} option forces the use of a minipage, which internally adjusts for
 a virtual 6-inch wide minipage, which then corrupts the \optn{lw} option.)
+
+For wrapped figures, overhang and number of lines are ignored.
 }
 
 \newcommand{\limitssiunitx}{%
@@ -3098,7 +3100,7 @@ This boolean may be tested by the user for later use.
 %<*package>
 % \fi
 %
-% \CheckSum{54272}
+% \CheckSum{54297}
 %
 % \CharacterTable
 % {Upper-case     \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
@@ -3238,6 +3240,7 @@ This boolean may be tested by the user for later use.
 % \changes{v0.896}{2021/04/08}{\ 2021/04/08}
 % \changes{v0.897}{2021/05/24}{\ 2021/05/24}
 % \changes{v0.898}{2021/05/29}{\ 2021/05/29}
+% \changes{v0.899}{2021/06/29}{\ 2021/06/29}
 
 
 
@@ -3341,6 +3344,8 @@ This boolean may be tested by the user for later use.
 % \begin{center}
 % \setlength{\parskip}{1ex}
 % \color{blue}
+% For a quick-start tutorial, see \cref{sec:tutorial}, \nameref{sec:tutorial}.
+%
 % For a list of supported features, see \cref{tab:supported}: \nameref{tab:supported}.
 %
 % To update existing projects, see \cref{sec:updates}: \nameref{sec:updates}.
@@ -3461,6 +3466,15 @@ This boolean may be tested by the user for later use.
 %
 % \begin{description}
 % \needspace{2\baselineskip}
+% \item[v0.899:] Minor updates.
+%   \begin{itemize}
+%       \item \prog{lwarpmk}: Warns if |\usepackage{lwarp}| is not detected.
+%       \item \pkg{graphics}: Added support for \optn{keepaspectratio}.
+%           \margintag{packages}
+%       \item \pkg{keyfloat}: Fix: \optn{lw} with \optn{h}.
+%       \item \pkg{multicol}: Improved \CSS.
+%   \end{itemize}
+% \needspace{2\baselineskip}
 % \item[v0.898:] Minor updates.
 %   \begin{itemize}
 %       \item Fewer underfull \cs{hbox} warnings.
@@ -6790,6 +6804,16 @@ This boolean may be tested by the user for later use.
 %
 % \subsection{Compiling the print version with \prog{lwarpmk}}
 %
+% \newcommand*{\LWRenablelwarpmk}{%
+%   If you have not yet done so,
+%   \trouble[Enable \prog{lwarpmk}]{lwarpmk=\filenm{lwarpmk.conf}}
+%   \trouble{lwarpmk=\prog{lwarpmk}}
+%   add \texttt{\cs{usepackage}\{lwarp\}} to the document,
+%   then compile the project a single time using \prog{pdflatex}, \prog{lualatex},
+%   or \prog{xelatex}.  This generates the file \filenm{lwarpmk.conf},
+%   which then allows the \prog{lwarpmk} program to be used.
+% }
+%
 % The \prog{lwarpmk} utility program is used to compile either the printed or
 % the \HTML\ version of the document.
 %
@@ -6797,6 +6821,8 @@ This boolean may be tested by the user for later use.
 %
 % \begin{enumerate}
 %
+% \item \LWRenablelwarpmk
+%
 % \item Re-compile the print version: \userentry{lwarpmk print}
 %
 %	\prog{lwarpmk} prints an introduction then checks to see if the document
@@ -6846,6 +6872,7 @@ This boolean may be tested by the user for later use.
 % |lwarpmk html| is used to recompile an \HTML\ version of the document.
 %
 % \begin{enumerate}
+% \item \LWRenablelwarpmk
 % \item Compile the \HTML\ version:
 %	\userentry{lwarpmk html}
 %
@@ -17720,6 +17747,7 @@ This boolean may be tested by the user for later use.
 % \changes{v0.893}{2020/10/18}{\filenm{lwarp.css}: Added \pkg{keystroke}.}
 % \changes{v0.894}{2020/12/15}{\filenm{lwarp.css}: \TeX\ logos no longer below baseline.}
 % \changes{v0.896}{2021/03/04}{\filenm{lwarp.css}: Added \element{main}, adjusted \element{sidetoccontainer} margin.}
+% \changes{v0.899}{2021/06/25}{\filenm{lwarp.css}: Improved \pkg{multicol}.}
 %
 % ^^A *lwarp.css
 %
@@ -19103,8 +19131,11 @@ section.textbody { margin: 0ex 1em 0ex 1em ;}
 
 div.multicolsheading { -webkit-column-span: all;
     -moz-column-span: all; column-span: all; }
-div.multicols { -webkit-columns: 3 380px ;
-    -moz-columns: 3 380px ; columns: 3 380px ; }
+div.multicols {
+    -webkit-columns: 3 auto ;
+    -moz-columns: 3 auto ;
+    columns: 3 auto ;
+}
 div.multicols p {margin-top: 0ex}
 
 
@@ -19412,6 +19443,14 @@ nav.botnavigation { display:none; }
 /* Only display the sidetoc's webpage title if a small screen */
 span.sidetocthetitle { display: none }
 
+@media screen and (max-width: 100em) {
+    div.multicols {
+        -webkit-columns: 2 auto ;
+        -moz-columns: 2 auto ;
+        columns: 2 auto ;
+    }
+}
+
 @media screen and (max-width: 50em) {
     div.sidetoccontainer {
         float: none ;
@@ -19432,6 +19471,11 @@ span.sidetocthetitle { display: none }
         display:block ;
         margin: 1ex 1em 1ex 1em ;
     }
+    div.multicols {
+        -webkit-columns: 1 auto ;
+        -moz-columns: 1 auto ;
+        columns: 1 auto ;
+    }
 }
 
 @media print {
@@ -20505,6 +20549,7 @@ MathJax = {
 % \changes{v0.81}{2020/03/04}{\prog{lwarpmk}: Improved error if in \pkg{lwarp} source directory.}
 % \changes{v0.84}{2020/03/30}{\prog{lwarpmk}: \optn{clean} also removes \filenm{comment_*.cut}}
 % \changes{v0.89}{2020/08/29}{\prog{lwarpmk}: \optn{clean} also removes \filenm{*.bbl}}
+% \changes{v0.899}{2021/05/30}{\prog{lwarpmk}: Warn if \pkg{lwarp} package not detected.}
 %
 % The following is only generated if the \optn{lwarpmk} option
 %   was given to \pkg{lwarp}.
@@ -20520,7 +20565,7 @@ MathJax = {
 -- Copyright 2016-2021 Brian Dunn
 
 
-printversion = "v0.898"
+printversion = "v0.899"
 requiredconfversion = "2" -- also at *lwarpmk.conf
 
 function printhelp ()
@@ -20587,7 +20632,9 @@ function splitfile (destfile,sourcefile)
 -- Split one large sourcefile into a number of files,
 -- starting with destfile.
 -- The file is split at each occurance of <!--|Start file|newfilename|*
+-- If lwarp is in use, sets usinglwarp.
 --
+usinglwarp = false ;
 print ("lwarpmk: Splitting " .. sourcefile .. " into " .. destfile) ;
 local sfile = io.open(sourcefile)
 io.output(destfile)
@@ -20597,11 +20644,23 @@ if ( (i~= nil) and (copen == "<!--") and (cstart == "Start file")) then
     -- split the file
     io.output(newfilename) ;
 else
+if ( (i~= nil) and (copen == "<!--") and (cstart == "Using lwarp")) then
+    -- verified the use of \usepackage{lwarp}
+    usinglwarp = true ;
+else
     -- not a splitpoint
     io.write (line .. "\n") ;
-end
+end end
 end -- do
 io.close(sfile)
+if ( usinglwarp == false ) then
+    print ("lwarpmk: ===")
+    print ("lwarpmk: \\usepackage{lwarp} was not detected.")
+    print ("lwarpmk: The HTML output will not be correct.")
+    print ("lwarpmk: Ensured that \\usepackage{lwarp} is enabled,")
+    print ("lwarpmk: then lwarpmk print and lwarpmk HTML again.")
+    print ("lwarpmk: ===")
+end
 end -- function
 
 
@@ -27173,10 +27232,23 @@ end -- not --version
 %    \begin{macrocode}
 \LWR@traceinfo{LWR@lwarpStart: Starting new file.}
 \LWR@filestart
-\LWR@traceinfo{LWR@lwarpStart: Generating first header.}
+%    \end{macrocode}
+% Tell \prog{lwarpmk} that the \pkg{lwarp} package is in use.
+% This allows \prog{lwarpmk} to warn if |usepackage{lwarp}| was somehow
+% disabled.
+% \changes{v0.899}{2021/05/30}{Warn if \pkg{lwarp} package not detected.}
+%    \begin{macrocode}
+\begingroup%
+\LWR@nullfonts%
+\LWR@htmlblockcomment{%
+|Using lwarp|%
+\LWR@htmlsectionfilename{\LWR@thisfilename}|%
+}
+\endgroup%
 %    \end{macrocode}
 % \changes{v0.73}{2019/06/23}{Fix: Empty header/footer.}
 %    \begin{macrocode}
+\LWR@traceinfo{LWR@lwarpStart: Generating first header.}
 \ifdefempty{\LWR@firstpagetop}{}{%
     \LWR@htmltag{header}\LWR@orignewline
     \LWR@startpars
@@ -39611,6 +39683,7 @@ end -- not --version
 \setcounter{LWR@virtualpagedepth}{0}
 %    \end{macrocode}
 %
+%
 % \begin{environment}{LWR@setvirtualpage} * \oarg{columns}
 %
 % If not nesting a minipage, adjust \cs{linewidth}, \cs{textwidth},
@@ -58518,6 +58591,10 @@ solid {\FancyVerbRuleColor{\LWR@origpound\LWR@tempcolor}} ; % space
 \newcommand*{\LWR@igangle}{}
 \newcommand*{\LWR@igxscale}{1}
 \newcommand*{\LWR@igyscale}{1}
+
+\newbool{LWR@igkeepaspectratio}
+\boolfalse{LWR@igkeepaspectratio}
+
 \newcommand*{\LWR@igclass}{inlineimage}
 %    \end{macrocode}
 % \changes{v0.65}{2018/12/19}{\pkg{graphics}: Added \cs{includegraphics} \attribute{alt} key.}
@@ -58589,6 +58666,14 @@ solid {\FancyVerbRuleColor{\LWR@origpound\LWR@tempcolor}} ; % space
 %    \end{macrocode}
 %
 %
+% Handle \optn{keepaspectratio} key:
+% \changes{v0.899}{2021/06/25}{\pkg{graphics}: Supports \optn{keepaspectratio}.}
+%    \begin{macrocode}
+\define@key{igraph}{keepaspectratio}[false]{%
+    \booltrue{LWR@igkeepaspectratio}%
+}
+%    \end{macrocode}
+%
 % Handle \optn{origin} key:
 % \changes{v0.52}{2018/03/27}{\pkg{graphics}: Added defaults.}
 %    \begin{macrocode}
@@ -58648,7 +58733,6 @@ solid {\FancyVerbRuleColor{\LWR@origpound\LWR@tempcolor}} ; % space
 \define@key{igraph}{viewport}{}
 \define@key{igraph}{trim}{}
 \define@key{igraph}{totalheight}{}
-\define@key{igraph}{keepaspectratio}[true]{}
 \define@key{igraph}{clip}[true]{}
 \define@key{igraph}{draft}[true]{}
 \define@key{igraph}{type}{}
@@ -58772,7 +58856,7 @@ solid {\FancyVerbRuleColor{\LWR@origpound\LWR@tempcolor}} ; % space
 % \end{noindmacro}
 
 
-% \begin{noindmacro}{\LWR@ig@wpimagesizes} * \oarg{2: options} \oarg{3: options} \marg{4: filename}
+% \begin{noindmacro}{\LWR@ig@useactualimagesize} * \oarg{2: options} \oarg{3: options} \marg{4: filename}
 %
 % If formatting for a word processor, find and set the actual image size,
 % without rotation, using \PDF\ instead of \SVG\ to find the original bounding box:
@@ -58781,83 +58865,86 @@ solid {\FancyVerbRuleColor{\LWR@origpound\LWR@tempcolor}} ; % space
 % \changes{v0.62}{2018/10/27}{\pkg{graphics}: Fix: \bool{FormatWP}.}
 % \changes{v0.79}{2019/12/09}{\pkg{graphics}: Factored from \cs{LWR@includegraphicsb}.}
 %    \begin{macrocode}
-\newcommand*{\LWR@ig@wpimagesizes}[4]{%
-    \ifbool{FormatWP}{%
-        \begingroup%
-        \LWR@restoreorigformatting%
-        \ifpdf%
-        \appto\LWR@restoreorigformatting{%
-            \DeclareGraphicsExtensions{%
-                .pdf,.PDF,.gif,.GIF,.png,.PNG,.jpg,.JPG,.jpeg,.JPEG%
-            }%
+\newcommand*{\LWR@ig@useactualimagesize}[4]{%
+    \begingroup%
+    \LWR@restoreorigformatting%
+    \ifpdf%
+    \appto\LWR@restoreorigformatting{%
+        \DeclareGraphicsExtensions{%
+            .pdf,.PDF,.gif,.GIF,.png,.PNG,.jpg,.JPG,.jpeg,.JPEG%
         }%
-        \else% \ifpdf
-                \ifXeTeX%
-        \appto\LWR@restoreorigformatting{%
-            \DeclareGraphicsExtensions{%
-                .pdf,.PDF,.gif,.GIF,.png,.PNG,.jpg,.JPG,.jpeg,.JPEG%
-            }%
+    }%
+    \else% \ifpdf
+            \ifXeTeX%
+    \appto\LWR@restoreorigformatting{%
+        \DeclareGraphicsExtensions{%
+            .pdf,.PDF,.gif,.GIF,.png,.PNG,.jpg,.JPG,.jpeg,.JPEG%
+        }%
+    }%
+            \else%
+    \appto\LWR@restoreorigformatting{%
+        \DeclareGraphicsExtensions{%
+            .eps,.EPS,.gif,.GIF,.png,.PNG,.jpg,.JPG,.jpeg,.JPEG%
         }%
-                \else%
-        \appto\LWR@restoreorigformatting{%
-            \DeclareGraphicsExtensions{%
-                .eps,.EPS,.gif,.GIF,.png,.PNG,.jpg,.JPG,.jpeg,.JPEG%
+    }%
+            \fi%
+    \fi% \ifpdf
+%    \end{macrocode}
+% For a word processor, do not use rotation:
+%    \begin{macrocode}
+    \ifbool{FormatWP}{\define@key{Gin}{angle}{}}{}%
+%    \end{macrocode}
+%    \begin{macrocode}
+    \IfBooleanTF{#1}%
+    {% starred
+        \IfValueTF{#3}%
+        {%
+            \global\sbox{\LWR@imagesizebox}{%
+                \LWR@origincludegraphics*[#2][#3]{#4}%
             }%
         }%
-                \fi%
-        \fi% \ifpdf
-        \define@key{Gin}{angle}{}%
-        \IfBooleanTF{#1}%
-        {% starred
-            \IfValueTF{#3}%
+        {%
+            \IfValueTF{#2}%
             {%
                 \global\sbox{\LWR@imagesizebox}{%
-                    \LWR@origincludegraphics*[#2][#3]{#4}%
+                    \LWR@origincludegraphics*[#2]{#4}%
                 }%
-            }%
-            {%
-                \IfValueTF{#2}%
-                {%
-                    \global\sbox{\LWR@imagesizebox}{%
-                        \LWR@origincludegraphics*[#2]{#4}%
-                    }%
-                }{%
-                    \global\sbox{\LWR@imagesizebox}{%
-                        \LWR@origincludegraphics*{#4}%
-                    }%
+            }{%
+                \global\sbox{\LWR@imagesizebox}{%
+                    \LWR@origincludegraphics*{#4}%
                 }%
             }%
-        }% starred
-        {% not starred
-            \IfValueTF{#3}%
+        }%
+    }% starred
+    {% not starred
+        \IfValueTF{#3}%
+        {%
+            \global\sbox{\LWR@imagesizebox}{%
+                \LWR@origincludegraphics[#2][#3]{#4}%
+            }%
+        }%
+        {%
+            \IfValueTF{#2}%
             {%
                 \global\sbox{\LWR@imagesizebox}{%
-                    \LWR@origincludegraphics[#2][#3]{#4}%
+                    \LWR@origincludegraphics[#2]{#4}%
                 }%
-            }%
-            {%
-                \IfValueTF{#2}%
-                {%
-                    \global\sbox{\LWR@imagesizebox}{%
-                        \LWR@origincludegraphics[#2]{#4}%
-                    }%
-                }{%
-                    \global\sbox{\LWR@imagesizebox}{%
-                        \LWR@origincludegraphics{#4}%
-                    }%
+            }{%
+                \global\sbox{\LWR@imagesizebox}{%
+                    \LWR@origincludegraphics{#4}%
                 }%
             }%
-        }% not starred
-        \endgroup%
-        \settowidth{\LWR@igwidth}{\usebox{\LWR@imagesizebox}}%
-        \global\renewcommand*{\LWR@igwidthstyle}{%
-            width:\LWR@printlength{\LWR@igwidth}%
-        }%
-        \settoheight{\LWR@igheight}{\usebox{\LWR@imagesizebox}}%
-        \global\renewcommand*{\LWR@igheightstyle}{%
-            height:\LWR@printlength{\LWR@igheight}%
         }%
-    }{}% FormatWP
+    }% not starred
+    \endgroup%
+    \settowidth{\LWR@igwidth}{\usebox{\LWR@imagesizebox}}%
+    \global\renewcommand*{\LWR@igwidthstyle}{%
+        width:\LWR@printlength{\LWR@igwidth}%
+    }%
+    \settoheight{\LWR@igheight}{\usebox{\LWR@imagesizebox}}%
+    \global\renewcommand*{\LWR@igheightstyle}{%
+        height:\LWR@printlength{\LWR@igheight}%
+    }%
 }
 %    \end{macrocode}
 % \end{noindmacro}
@@ -59002,6 +59089,7 @@ solid {\FancyVerbRuleColor{\LWR@origpound\LWR@tempcolor}} ; % space
     \renewcommand*{\LWR@igxscale}{1}%
     \renewcommand*{\LWR@igyscale}{1}%
     \renewcommand*{\LWR@igclass}{inlineimage}%
+    \boolfalse{LWR@igkeepaspectratio}%
 %    \end{macrocode}
 % \changes{v0.65}{2018/12/19}{\pkg{graphics}: Added \cs{includegraphics} \attribute{alt} key.}
 % \changes{v0.74}{2019/08/20}{\pkg{graphics}: Add \cs{ThisAltText}.}
@@ -59055,10 +59143,15 @@ solid {\FancyVerbRuleColor{\LWR@origpound\LWR@tempcolor}} ; % space
 %    \end{macrocode}
 % ^^A \LWR@sanitize{\LWR@parsedfilename}%
 %
-% If formatting for a word processor, find and set the actual image size,
+% If formatting for a word processor, or if using \optn{keepaspectratio},
+% find and set the actual image size,
 % without rotation, using \PDF\ instead of \SVG\ to find the original bounding box:
+% \changes{v0.899}{2021/06/25}{\pkg{graphics}: Supports \optn{keepaspectratio}.}
 %    \begin{macrocode}
-    \LWR@ig@wpimagesizes{#1}{#2}{#3}{#4}%
+    \ifboolexpr{
+        bool {FormatWP} or
+        bool {LWR@igkeepaspectratio}
+    }{\LWR@ig@useactualimagesize{#1}{#2}{#3}{#4}}{}%
 %    \end{macrocode}
 %
 % Create the \HTML\ reference with the graphicspath, filename, extension,
@@ -61926,10 +62019,10 @@ do not attempt to patch lwarp's version of `hyperref'.)\MessageBreak}
 
 \renewcommand*{\KFLT@maybeendfloatrow}{%
     \ifnumless{\value{KFLT@thiscol}}{\value{KFLT@numcols}}%
-    {}% thiscol < numcols
-    {% >=
-        \defcounter{KFLT@thiscol}{0}%
-    }%
+        {}% thiscol < numcols
+        {% >=
+            \defcounter{KFLT@thiscol}{0}%
+        }%
 }%
 
 \renewcommand{\KFLT@trackrows}%
@@ -61967,17 +62060,37 @@ do not attempt to patch lwarp's version of `hyperref'.)\MessageBreak}
 % \begin{lrbox}{\KFLT@envbox}%
 \ifthenelse{\NOT\equal{\KFLT@lw}{}}%
     {%
-        \KFLT@frame{\includegraphics%
-        [scale=\KFLT@s,width=\KFLT@imagewidth]{#1}}%
+%    \end{macrocode}
+% \changes{v0.899}{2021/06/25}{\pkg{keyfloat}: Fix: \optn{lw} w/ \optn{h}.}
+%    \begin{macrocode}
+        \ifdimgreater{\KFLT@h}{0pt}%
+        {%
+            \KFLT@frame{%
+                \includegraphics%
+                [%
+                    scale=\KFLT@s,%
+                    width=\KFLT@imagewidth,%
+                    height=\KFLT@h,%
+                    \KFLT@keepaspectratio,%
+                ]{#1}%
+            }%
+        }%
+        {%
+            \KFLT@frame{\includegraphics%
+            [scale=\KFLT@s,width=\KFLT@imagewidth]{#1}}%
+        }%
     }%
     {% not linewidth
         \ifthenelse{\dimtest{\KFLT@w}{>}{0pt}}%
         {% width is given
             \ifthenelse{\dimtest{\KFLT@h}{>}{0pt}}%
             {% w and h
-                \KFLT@frame{\includegraphics%
-                [scale=\KFLT@s,%
-                width=\KFLT@imagewidth,height=\KFLT@h]{#1}}%
+                \KFLT@frame{\includegraphics[%
+                    scale=\KFLT@s,%
+                    width=\KFLT@imagewidth,%
+                    height=\KFLT@h,%
+                    \KFLT@keepaspectratio,%
+                ]{#1}}%
             }% w and h
             {% only w
                 \KFLT@frame{\includegraphics%
diff --git a/macros/latex/contrib/lwarp/lwarp.pdf b/macros/latex/contrib/lwarp/lwarp.pdf
index 2a35f3ec74..387f0601f7 100644
--- a/macros/latex/contrib/lwarp/lwarp.pdf
+++ b/macros/latex/contrib/lwarp/lwarp.pdf
diff --git a/macros/latex/contrib/lwarp/lwarpmk.lua b/macros/latex/contrib/lwarp/lwarpmk.lua
index a34d61e216..cb684409a3 100755
--- a/macros/latex/contrib/lwarp/lwarpmk.lua
+++ b/macros/latex/contrib/lwarp/lwarpmk.lua
@@ -2,7 +2,7 @@
 
 -- Copyright 2016-2021 Brian Dunn
 
-printversion = "v0.898"
+printversion = "v0.899"
 requiredconfversion = "2" -- also at *lwarpmk.conf
 
 function printhelp ()
@@ -66,7 +66,9 @@ function splitfile (destfile,sourcefile)
 -- Split one large sourcefile into a number of files,
 -- starting with destfile.
 -- The file is split at each occurance of <!--|Start file|newfilename|*
+-- If lwarp is in use, sets usinglwarp.
 --
+usinglwarp = false ;
 print ("lwarpmk: Splitting " .. sourcefile .. " into " .. destfile) ;
 local sfile = io.open(sourcefile)
 io.output(destfile)
@@ -76,11 +78,23 @@ if ( (i~= nil) and (copen == "<!--") and (cstart == "Start file")) then
     -- split the file
     io.output(newfilename) ;
 else
+if ( (i~= nil) and (copen == "<!--") and (cstart == "Using lwarp")) then
+    -- verified the use of \usepackage{lwarp}
+    usinglwarp = true ;
+else
     -- not a splitpoint
     io.write (line .. "\n") ;
-end
+end end
 end -- do
 io.close(sfile)
+if ( usinglwarp == false ) then
+    print ("lwarpmk: ===")
+    print ("lwarpmk: \\usepackage{lwarp} was not detected.")
+    print ("lwarpmk: The HTML output will not be correct.")
+    print ("lwarpmk: Ensured that \\usepackage{lwarp} is enabled,")
+    print ("lwarpmk: then lwarpmk print and lwarpmk HTML again.")
+    print ("lwarpmk: ===")
+end
 end -- function
 
 function cvalueerror ( line, linenum , cvalue )