[TeX][FLOSS][publishing] multipagebox.sty
LaTeXで囲み記事用の環境を用意したのでバックアップ。
最新版は：
http://ideotype.svn.sourceforge.net/viewvc/ideotype/trunk/lib/multipagebox.sty

主な特徴：

* 複数ページにわたると分割される
* 入れ子可能
* 外側と内側のアキ・角の丸み・線の太さ・背景色を指定できる
* FLOSS

既知の問題点：

* 見出しを入れたときの内側の天地のアキがややおかしい
* 線を太くすると外側にも太る
* 角の線や塗りの合わせ目にわずかなずれがある（0.05mm程度）
* 目を覆いたくなる強引で冗長なコード
* その他多数

----

%% multipagebox.sty
%% Multi-page Spanning Box with Round Corners
%% 2008 Hisashi Morita
%%
%% How it works:
%%
%%   +--------+         +--------+          -----------
%%   |        |  loop   | first  |         /first slice\
%%   |        |         +--------+         +-----------+
%%   |        | vsplit  +--------+         +-----------+
%%   |  rest  | ------> |  gap   |   -->   | mid slice |
%%   |        |         +--------+         +-----------+
%%   |        |         +--------+              ...
%%   |        |         |  rest  |         +-----------+
%%   |        | < - - - |        |         \last slice /
%%   +--------+         +--------+          -----------
%%
%%   slice = picture + content (i.e. |foo| = |   | + foo)
%%
%% References:
%%   Hideki Isozaki, "LaTeX Jiyu Jizai" (Sciencesha, 1992)
%%   Tetsumi Yoshinaga, "LaTeX2e Macro & Class Programming Jissen Kaisetsu" (Gijutsu Hyoronsha, 2003)

%%
%% package declarations
%%

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{multipagebox}
\DeclareOption*{%  %% delegate options (mostly dviware names) to pict2e and color
  \PassOptionsToPackage{\CurrentOption}{pict2e}
  \PassOptionsToPackage{\CurrentOption}{color}
  \PassOptionsToPackage{usenames}{color}
}
\ProcessOptions
\RequirePackage{pict2e}%  %% required for smooth rounded corner
\RequirePackage{color}
\definecolor{gray10}{cmyk}{0.0, 0.0, 0.0, 0.1}
\definecolor{gray20}{cmyk}{0.0, 0.0, 0.0, 0.2}
\definecolor{gray30}{cmyk}{0.0, 0.0, 0.0, 0.3}
\definecolor{gray40}{cmyk}{0.0, 0.0, 0.0, 0.4}
\definecolor{gray50}{cmyk}{0.0, 0.0, 0.0, 0.5}
\definecolor{gray60}{cmyk}{0.0, 0.0, 0.0, 0.6}
\definecolor{gray70}{cmyk}{0.0, 0.0, 0.0, 0.7}
\definecolor{gray80}{cmyk}{0.0, 0.0, 0.0, 0.8}
\definecolor{gray90}{cmyk}{0.0, 0.0, 0.0, 0.9}

%%
%% public parameters
%%

\newlength\mpboxborderwidth   \mpboxborderwidth   =  0.4pt
\newlength\mpboxpaddingtop    \mpboxpaddingtop    =  1em
\newlength\mpboxpaddingbottom \mpboxpaddingbottom =  1em
\newlength\mpboxpaddingleft   \mpboxpaddingleft   =  1em
\newlength\mpboxpaddingright  \mpboxpaddingright  =  1em
\newlength\mpboxmargintop     \mpboxmargintop     =  \baselineskip
\newlength\mpboxmarginbottom  \mpboxmarginbottom  =  \baselineskip
% \newlength\mpboxmarginleft    \mpboxmarginleft    =  0em
% \newlength\mpboxmarginright   \mpboxmarginright   =  0em
\newlength\mpboxparindent     \mpboxparindent     =  \parindent
\newlength\mpboxcornerradius  \mpboxcornerradius  =  0.5em  % 0 < r <= \mpboxpadding*
\newcommand{\mpboxbgcolor}{gray20}
\newcommand{\mpboxbordercolor}{gray80}

%%
%% private objects
%%

\newbox\mpbox@first      %% first fragment of split content
\newbox\mpbox@rest       %% the rest
\newlength\mpbox@gap     %% gap between first and rest
\newif\ifmpbox@havemore  %% have more content or not
\newif\ifmpbox@inside    %% inside multipagebox or not
\newbox\mpbox@tempbox
\newbox\mpbox@contentbox
\newlength\mpbox@tempdim
\newlength\mpbox@hborderlength
\newlength\mpbox@vborderlength

%%
%% common utilities
%%

%% split content destructively: 1:first, 2:rest, 3:gap
\def\mpbox@split#1#2#3{%
  #3=\ht#2                               %% gap := height_all
  \advance#3\dp#2                        %% gap := gap + depth_all
  \setbox#1\vsplit#2 to\z@               %% first, rest := split(content)
  \setbox#1\vbox{\unvbox#1}%             %% repack first
  \setbox\mpbox@tempbox\vbox{%           %% concat first and rest
    \copy#1\copy#2}%
  \advance\mpbox@gap-\ht\mpbox@tempbox   %% gap := gap - height_(first+rest)
  \advance\mpbox@gap-\dp\mpbox@tempbox}  %% gap := gap - depth_(first+rest)
%% change height destructively: 1:target, 2:length
\def\mpbox@addheightx#1#2{%
  \mpbox@tempdim\ht#1
  \advance\mpbox@tempdim#2
  \ht#1\mpbox@tempdim}

%% change depth destructively: 1:target, 2:length
\def\mpbox@adddepthx#1#2{%
  \mpbox@tempdim\dp#1
  \advance\mpbox@tempdim#2
  \dp#1\mpbox@tempdim}

%%
%% draw slices: square corner version (drawn with rules)
%%

\def\mpbox@slice#1{%
  \hbox to \hsize{%
    \vrule\@width\mpboxborderwidth
    \hskip\mpboxpaddingleft
    \box#1\hfil
    \hskip\mpboxpaddingright
    \vrule\@width\mpboxborderwidth}}

\def\mpbox@singleslice#1{%
  \vbox{%
    \hrule\@height\mpboxborderwidth
    \setbox\mpbox@contentbox\vbox{\vskip\mpboxpaddingtop\copy#1}%
    \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
    \mpbox@adddepthx\mpbox@contentbox\mpboxpaddingbottom
    \mpbox@slice\mpbox@contentbox
    \hrule\@height\mpboxborderwidth}}

\def\mpbox@firstslice#1{%
  \vbox{%
    \hrule\@height\mpboxborderwidth
    \setbox\mpbox@contentbox\vbox{\vskip\mpboxpaddingtop\copy#1}%
    \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
    \mpbox@slice\mpbox@contentbox}}

\def\mpbox@midslice#1{%
  \setbox\mpbox@contentbox\vbox{\copy#1}%
  \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
  \mpbox@slice\mpbox@contentbox}

\def\mpbox@lastslice#1{%
  \vtop{%
    \setbox\mpbox@contentbox\vbox{\copy#1}%
    \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
    \mpbox@adddepthx\mpbox@contentbox\mpboxpaddingbottom
    \mpbox@slice\mpbox@contentbox
    \hrule\@height\mpboxborderwidth}}

%%
%% draw slices: round corner version (drawn with picture)
%%

\def\mpbox@singleslicewithroundcorner#1{%
  \vbox{%
    \setlength{\mpbox@hborderlength}{\hsize}%
    \addtolength{\mpbox@hborderlength}{-2\mpboxcornerradius}%
    \setbox\mpbox@contentbox\vbox{\addvspace{\mpboxpaddingtop}\copy#1}%
    \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
    \mpbox@adddepthx\mpbox@contentbox\mpboxpaddingbottom
    \setlength{\mpbox@vborderlength}{\ht\mpbox@contentbox}%
    \addtolength{\mpbox@vborderlength}{\dp\mpbox@contentbox}%
    \addtolength{\mpbox@vborderlength}{-2\mpboxcornerradius}%
    \noindent
    %% paint background
    \begin{picture}(0,0)%
      \setlength{\unitlength}{\ht\mpbox@contentbox}%
      \put(0,1){%                     %% move from baseline to nw corner
        \setlength{\unitlength}{\mpboxcornerradius}%
        \put(1,-1){\color{\mpboxbgcolor}{\circle*{2}}}%  paint nw corner
%        \qbezier(0,-1)(0,0)(1,0)%     %% draw nw corner
        \put(1,0){%
          \setlength{\unitlength}{0.5\mpbox@hborderlength}%
          \put(1,0){%                 %% paint whole square (except for w and e side)
            \setlength{\unitlength}{\ht\mpbox@contentbox}%
            \addtolength{\unitlength}{\dp\mpbox@contentbox}%
            \linethickness{\mpbox@hborderlength}%
            \color{\mpboxbgcolor}{\line(0,-1){1}}%
          }%
          \put(1,0){%
            \setlength{\unitlength}{\mpboxcornerradius}%
            \put(0,-1){%              %% paint whole square (except for n and s row)
              \setlength{\unitlength}{\mpbox@vborderlength}%
              \setlength{\mpbox@tempdim}{\mpbox@hborderlength}%
              \addtolength{\mpbox@tempdim}{2\mpboxcornerradius}%
              \linethickness{\mpbox@tempdim}%
              \color{\mpboxbgcolor}{\line(0,-1){1}}%
            }%
          }%
          \setlength{\unitlength}{\mpbox@hborderlength}%
          \line(1,0){1}%              %% draw n border (BUG?: ne/se corner not painted without this line)
          \put(0,0){%
            \setlength{\unitlength}{\mpboxcornerradius}%
            \put(0,-1){\color{\mpboxbgcolor}{\circle*{2}}}% %% paint ne corner
%            \qbezier(0,0)(1,0)(1,-1)% %% draw ne corner
            \put(1,-1){%
              \setlength{\unitlength}{\mpbox@vborderlength}%
%              \line(0,-1){1}%         %% draw e border
              \put(0,-1){%
                \setlength{\unitlength}{\mpboxcornerradius}%
                \put(-1,0){\color{\mpboxbgcolor}{\circle*{2}}}% %% paint se corner
%                \qbezier(0,0)(0,-1)(-1,-1)% %% draw se corner
                \put(-1,-1){%
                  \setlength{\unitlength}{\mpbox@hborderlength}%
%                  \line(-1,0){1}%     %% draw s border
                  \put(-1,0){%
                    \setlength{\unitlength}{\mpboxcornerradius}%
                    \put(0,1){\color{\mpboxbgcolor}{\circle*{2}}}% %% paint nw corner
%                    \qbezier(0,0)(-1,0)(-1,1)% %% draw sw corner
%                    \put(-1,1){%
%                      \setlength{\unitlength}{\mpbox@vborderlength}%
%                      \line(0,1){1}%  %% draw w border
%                    }%
                  }%
                }%
              }%
            }%
          }%
        }%
      }%
    \end{picture}%
    %% draw border
    \begin{picture}(0,0)%
      \color{\mpboxbordercolor}%
      \setlength{\unitlength}{\ht\mpbox@contentbox}%
      \put(0,1){%                     %% move from baseline to nw corner
        \setlength{\unitlength}{\mpboxcornerradius}%
        \qbezier(0,-1)(0,0)(1,0)%     %% draw nw corner
        \put(1,0){%
          \setlength{\unitlength}{\mpbox@hborderlength}%
          \line(1,0){1}%              %% draw n border
          \put(0,0){%
            \setlength{\unitlength}{\mpboxcornerradius}%
            \qbezier(0,0)(1,0)(1,-1)% %% draw ne corner
            \put(1,-1){%
              \setlength{\unitlength}{\mpbox@vborderlength}%
              \line(0,-1){1}%         %% draw e border
              \put(0,-1){%
                \setlength{\unitlength}{\mpboxcornerradius}%
                \qbezier(0,0)(0,-1)(-1,-1)% %% draw se corner
                \put(-1,-1){%
                  \setlength{\unitlength}{\mpbox@hborderlength}%
                  \line(-1,0){1}%     %% draw s border
                  \put(-1,0){%
                    \setlength{\unitlength}{\mpboxcornerradius}%
                    \qbezier(0,0)(-1,0)(-1,1)% %% draw sw corner
                    \put(-1,1){%
                      \setlength{\unitlength}{\mpbox@vborderlength}%
                      \line(0,1){1}%  %% draw w border
                    }%
                  }%
                }%
              }%
            }%
          }%
        }%
      }%
    \end{picture}%
    \hbox to \hsize{%
      \hskip\mpboxborderwidth
      \hskip\mpboxpaddingleft
      \box\mpbox@contentbox\hfil
      \hskip\mpboxpaddingright
      \hskip\mpboxborderwidth}%
  }}

\def\mpbox@firstslicewithroundcorner#1{%
  \vbox{%
    \setlength{\mpbox@hborderlength}{\hsize}%
    \addtolength{\mpbox@hborderlength}{-2\mpboxcornerradius}%
    \setbox\mpbox@contentbox\vbox{\addvspace{\mpboxpaddingtop}\copy#1}%
    \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
    \setlength{\mpbox@vborderlength}{\ht\mpbox@contentbox}%
    \ifdim 0pt<\dp\mpbox@contentbox
      \addtolength{\mpbox@vborderlength}{\dp\mpbox@contentbox}%
    \fi
    \ifdim\mpboxcornerradius<\mpbox@vborderlength
      \addtolength{\mpbox@vborderlength}{-\mpboxcornerradius}%
    \else
      \setlength{\mpbox@vborderlength}{0pt}%
    \fi
    \noindent
    %% paint background
    \begin{picture}(0,0)%
      \setlength{\unitlength}{\dp\mpbox@contentbox}%
      \put(0,-1){%                    %%  move from baseline to s of w border
        \setlength{\unitlength}{\mpbox@vborderlength}%
%        \line(0,1){1}%                %% draw w border
        \put(0,1){%
          \setlength{\unitlength}{\mpboxcornerradius}%
%          \qbezier(0,0)(0,1)(1,1)%    %% draw nw corner
          \put(1,1){%
            \setlength{\unitlength}{0.5\mpbox@hborderlength}%
            \put(1,0){%               %% paint whole square (except for left side and right side)
              \setlength{\unitlength}{\ht\mpbox@contentbox}%
              \addtolength{\unitlength}{\dp\mpbox@contentbox}%
              \linethickness{\mpbox@hborderlength}%
              \color{\mpboxbgcolor}{\line(0,-1){1}}%
            }%
            \put(1,0){%
              \setlength{\unitlength}{\mpboxcornerradius}%
              \put(0,-1){%            %% paint whole square (except for top row and bottom row)
                \setlength{\unitlength}{\mpbox@vborderlength}%
                \setlength{\mpbox@tempdim}{\mpbox@hborderlength}%
                \addtolength{\mpbox@tempdim}{2\mpboxcornerradius}%
                \linethickness{\mpbox@tempdim}%
                \color{\mpboxbgcolor}{\line(0,-1){1}}%
              }%
            }%
            \setlength{\unitlength}{\mpboxcornerradius}%
            \put(0,-1){\color{\mpboxbgcolor}{\circle*{2}}}% %% paint nw corner
            \setlength{\unitlength}{\mpbox@hborderlength}%
            \line(1,0){1}%            %% n border (BUG?: ne corner not painted without this line)
            \put(0,0){%
              \setlength{\unitlength}{\mpboxcornerradius}%
              \put(0,-1){\color{\mpboxbgcolor}{\circle*{2}}}% %% paint ne corner
%              \qbezier(0,0)(1,0)(1,-1)% %% draw ne corner
%              \put(1,-1){%
%                \setlength{\unitlength}{\mpbox@vborderlength}%
%                \line(0,-1){1}%       %% draw e border
%              }%
            }%
          }%
        }%
      }%
    \end{picture}%
    %% draw border
    \begin{picture}(0,0)%
      \color{\mpboxbordercolor}%
      \setlength{\unitlength}{\dp\mpbox@contentbox}%
      \put(0,-1){%                    %% move from baseline to s of w border
        \setlength{\unitlength}{\mpbox@vborderlength}%
        \line(0,1){1}%                %% draw w border
        \put(0,1){%
          \setlength{\unitlength}{\mpboxcornerradius}%
          \qbezier(0,0)(0,1)(1,1)%    %% draw nw corner
          \put(1,1){%
            \setlength{\unitlength}{\mpbox@hborderlength}%
            \line(1,0){1}%            %% draw n border
            \put(0,0){%
              \setlength{\unitlength}{\mpboxcornerradius}%
              \qbezier(0,0)(1,0)(1,-1)% %% draw ne corner
              \put(1,-1){%
                \setlength{\unitlength}{\mpbox@vborderlength}%
                \line(0,-1){1}%       %% draw e border
              }%
            }%
          }%
        }%
      }%
    \end{picture}%
    \hbox to \hsize{%
      \hskip\mpboxborderwidth
      \hskip\mpboxpaddingleft
      \box\mpbox@contentbox\hfil
      \hskip\mpboxpaddingright
      \hskip\mpboxborderwidth}%
  }}

\def\mpbox@midslicewithroundedcorner#1{%
  \vbox{%
    \setlength{\mpbox@hborderlength}{\hsize}%
    \addtolength{\mpbox@hborderlength}{-2\mpboxcornerradius}%
    \setbox\mpbox@contentbox\vbox{\copy#1}%
    \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
    \setlength{\mpbox@vborderlength}{\ht\mpbox@contentbox}%
    \addtolength{\mpbox@vborderlength}{\dp\mpbox@contentbox}%
    \noindent
    %% paint background
    \begin{picture}(0,0)%
      \setlength{\unitlength}{\ht\mpbox@contentbox}%
      \put(0,1){%                     %% move from baseline to n of w border
        \setlength{\unitlength}{0.5\mpbox@hborderlength}%
        \put(1,0){%
          \setlength{\unitlength}{\mpboxcornerradius}%
          \put(1,0){%                 %% paint square
            \setlength{\unitlength}{\mpbox@vborderlength}%
            \setlength{\mpbox@tempdim}{\mpbox@hborderlength}%
            \addtolength{\mpbox@tempdim}{2\mpboxcornerradius}%
            \linethickness{\mpbox@tempdim}%
            \color{\mpboxbgcolor}{\line(0,-1){1}}%
          }%
        }%
%        \setlength{\unitlength}{\mpbox@vborderlength}%
%        \line(0,-1){1}%               %% draw w border
%        \setlength{\unitlength}{\hsize}%
%        \put(1,0){%
%          \setlength{\unitlength}{\mpbox@vborderlength}%
%          \line(0,-1){1}%             %% draw e border
%        }%
      }%
    \end{picture}%
    %% draw border
    \begin{picture}(0,0)%
      \color{\mpboxbordercolor}%
      \setlength{\unitlength}{\ht\mpbox@contentbox}%
      \put(0,1){%                     %% move from baseline to n of w border
        \setlength{\unitlength}{\mpbox@vborderlength}%
        \line(0,-1){1}%               %% draw w border
        \setlength{\unitlength}{\hsize}%
        \put(1,0){%
          \setlength{\unitlength}{\mpbox@vborderlength}%
          \line(0,-1){1}%             %% draw e border
        }%
      }%
    \end{picture}%
    \hbox to \hsize{%
      \hskip\mpboxborderwidth
      \hskip\mpboxpaddingleft
      \box\mpbox@contentbox\hfil
      \hskip\mpboxpaddingright
      \hskip\mpboxborderwidth}%
  }}

\def\mpbox@lastslicewithroundcorner#1{%
  \vtop{%

    \setlength{\mpbox@hborderlength}{\hsize}%
    \addtolength{\mpbox@hborderlength}{-2\mpboxcornerradius}%
    \setbox\mpbox@contentbox\vbox{\copy#1}%
    \mpbox@adddepthx\mpbox@contentbox\mpbox@gap
    \mpbox@adddepthx\mpbox@contentbox\mpboxpaddingbottom
    \setlength{\mpbox@vborderlength}{\ht\mpbox@contentbox}%
    \addtolength{\mpbox@vborderlength}{\dp\mpbox@contentbox}%
    \addtolength{\mpbox@vborderlength}{-\mpboxcornerradius}%
    \noindent
    %% paint background
    \begin{picture}(0,0)%
      \setlength{\unitlength}{\ht\mpbox@contentbox}%
      \put(0,1){%
        \setlength{\unitlength}{\mpboxcornerradius}%
        \put(1,0){%
          \setlength{\unitlength}{0.5\mpbox@hborderlength}%
          \put(1,0){%                 %% paint whole square (except for left side and right side)
            \setlength{\unitlength}{\ht\mpbox@contentbox}%
            \addtolength{\unitlength}{\dp\mpbox@contentbox}%
            \linethickness{\mpbox@hborderlength}%
            \color{\mpboxbgcolor}{\line(0,-1){1}}%
          }%
          \put(1,0){%
            \setlength{\unitlength}{\mpboxcornerradius}%
            \put(0,0){%               %% paint whole square (except for top row and bottom row)
              \setlength{\unitlength}{\mpbox@vborderlength}%
              \setlength{\mpbox@tempdim}{\mpbox@hborderlength}%
              \addtolength{\mpbox@tempdim}{2\mpboxcornerradius}%
              \linethickness{\mpbox@tempdim}%
              \color{\mpboxbgcolor}{\line(0,-1){1}}%
            }%
          }%
        }%
        \setlength{\unitlength}{\mpbox@vborderlength}%
%        \line(0,-1){1}%              %% draw w border
        \put(0,-1){%
          \setlength{\unitlength}{\mpboxcornerradius}%
          \put(1,0){\color{\mpboxbgcolor}{\circle*{2}}}% %% paint sw corner
%          \qbezier(0,0)(0,-1)(1,-1)%  %% draw sw corner
          \put(1,-1){%
            \setlength{\unitlength}{\mpbox@hborderlength}%
            \line(1,0){1}%            %% draw s border (BUG?: se corner not painted without this line)
            \put(0,0){%
              \setlength{\unitlength}{\mpboxcornerradius}%
              \put(0,1){\color{\mpboxbgcolor}{\circle*{2}}}% %% paint se corner
%              \qbezier(0,0)(1,0)(1,1)% %% draw se corner
              \put(1,1){%
                \setlength{\unitlength}{\mpbox@vborderlength}%
%                \line(0,1){1}%       %% draw e border
              }%
            }%
          }%
        }%
      }%
    \end{picture}%
    %% draw border
    \begin{picture}(0,0)%
      \color{\mpboxbordercolor}%
      \setlength{\unitlength}{\ht\mpbox@contentbox}%
      \put(0,1){%
        \setlength{\unitlength}{\mpbox@vborderlength}%
        \line(0,-1){1}%               %% draw w border
        \put(0,-1){%
          \setlength{\unitlength}{\mpboxcornerradius}%
          \qbezier(0,0)(0,-1)(1,-1)%  %% draw sw corner
          \put(1,-1){%
            \setlength{\unitlength}{\mpbox@hborderlength}%
            \line(1,0){1}%            %% draw s border
            \put(0,0){%
              \setlength{\unitlength}{\mpboxcornerradius}%
              \qbezier(0,0)(1,0)(1,1)% %% draw se corner
              \put(1,1){%
                \setlength{\unitlength}{\mpbox@vborderlength}%
                \line(0,1){1}%        %% draw e border
              }%
            }%
          }%
        }%
      }%
    \end{picture}%
    \hbox to \hsize{%
      \hskip\mpboxborderwidth
      \hskip\mpboxpaddingleft
      \box\mpbox@contentbox\hfil
      \hskip\mpboxpaddingright
      \hskip\mpboxborderwidth}%
  }}

%%
%% beginning of environment
%%

\def\multipagebox{%
  \ifmpbox@inside
    \mpbox@insidefalse
    %% vspace for margin should not be disabled even if inside multipagebox
    \addvspace{\mpboxmargintop}%
    \mpbox@insidetrue
  \else
    \addvspace{\mpboxmargintop}%
  \fi
  \setbox\mpbox@rest\vbox\bgroup  %% start of content (vbox \mpbox@rest)
    \advance\linewidth -2\mpboxborderwidth
    \advance\linewidth -\mpboxpaddingleft
    \advance\linewidth -\mpboxpaddingright
    \hsize=\linewidth
    \@parboxrestore
    \parindent\mpboxparindent
    \mpbox@insidetrue             %% disable \addvspace at start of headings
    \relax}

%%
%% end of environment and main loop
%%

\def\endmultipagebox{%
  \mpbox@insidefalse              %% enable \addvspace at start of headings again
  \egroup                         %% end of content (vbox \mpbox@rest)
  \ifhmode\par\fi
  {%
    \noindent
    \mpbox@havemoretrue
    \linethickness{\mpboxborderwidth}%
    \baselineskip=0pt             %% suppress space between lines
    \lineskiplimit=0pt            %%
    \lineskip=0pt                 %%
    \vfuzz=\maxdimen              %% suppress warnings
    \vbadness=10000               %%
    \splittopskip=\topskip        %% top skip of rest
    \splitmaxdepth=\maxdimen      %% max depth of rest
    \mpbox@split\mpbox@first\mpbox@rest\mpbox@gap
    %% overwrite addvspace to be suppressed if mpbox@inside is true
    \def\addvspace##1{%
      \ifvmode
        \if@minipage\else
          \ifmpbox@inside\else
            \ifdim \lastskip =\z@
             \vskip ##1\relax
            \else
              \@tempskipb##1\relax
              \@xaddvskip
            \fi
          \fi
        \fi
      \else
        \@noitemerr
      \fi}%
    %% overwrite latex error message to report more info
    \def\@badlinearg{%
      \@latex@error{%
         Bad \protect\line\space or \protect\vector
         \space argument
         (\unitlength: \the\unitlength,
          \@linelen: \the\@linelen,
          \mpboxcornerradius: \the\mpboxcornerradius,
          \mpbox@hborderlength: \the\mpbox@hborderlength,
          \mpbox@vborderlength: \the\mpbox@vborderlength,
          \ht\mpbox@tempbox: \the\ht\mpbox@tempbox,
          \dp\mpbox@tempbox: \the\dp\mpbox@tempbox,
          \mpboxpaddingbottom: \the\mpboxpaddingbottom)
         }\@ehb}%
    %% start of loop to construct slices
    \ifvoid\mpbox@rest            %% there is only one slice
      \def\mpbox@allslices{%
%        \mpbox@singleslice\mpbox@first}%
        \mpbox@singleslicewithroundcorner\mpbox@first}%
    \else                         %% multiple slices
      \def\mpbox@allslices{%
%        \mpbox@firstslice\mpbox@first
        \mpbox@firstslicewithroundcorner\mpbox@first
        \hfil
        \loop
          \mpbox@split\mpbox@first\mpbox@rest\mpbox@gap
          \leavevmode
          \ifvoid\mpbox@rest      %% is this the last slice?
            \mpbox@havemorefalse
%            \mpbox@lastslice\mpbox@first
            \mpbox@lastslicewithroundcorner\mpbox@first
          \else                   %% not yet reached to the end
%            \mpbox@midslice\mpbox@first
            \mpbox@midslicewithroundedcorner\mpbox@first
          \fi
          \hfil
        \ifmpbox@havemore\repeat}%
    \fi
    %% end of loop to construct slices
    \leavevmode
    \mpbox@allslices              %% put all slices
    \par
  }%
  \ifmpbox@inside
    \mpbox@insidefalse
    \addvspace{\mpboxmarginbottom}%
    \mpbox@insidetrue
  \else
    \addvspace{\mpboxmarginbottom}%
  \fi
}

----

@@ -524,6 +524,7 @@
     \addvspace{\mpboxmargintop}%
   \fi
   \setbox\mpbox@rest\vbox\bgroup  %% start of content (vbox \mpbox@rest)
+    \let\@footnotetext\mpbox@footnotetext
     \advance\linewidth -2\mpboxborderwidth
     \advance\linewidth -\mpboxpaddingleft
     \advance\linewidth -\mpboxpaddingright
@@ -603,6 +604,8 @@
           \else                   %% not yet reached to the end
 %            \mpbox@midslice\mpbox@first
             \mpbox@midslicewithroundedcorner\mpbox@first
+            \the\mpbox@footnote
+            \global\mpbox@footnote{}
           \fi
           \hfil
         \ifmpbox@havemore\repeat}%
@@ -620,3 +623,8 @@
     \addvspace{\mpboxmarginbottom}%
   \fi
 }
+
+\newtoks\mpbox@footnote
+\def\mpbox@footnotetext#1{%
+  \edef\@tempa{\the\mpbox@footnote\noexpand\footnotetext[\the\c@footnote]}%
+  \global\mpbox@footnote\expandafter{\@tempa{#1}}}%