tabu 1.5 (8dec10)

git-svn-id: svn://tug.org/texlive/trunk@20693 c570f23f-e606-0410-a88d-b1316a301751

6 files changed, 2065 insertions, 1247 deletions

diff --git a/Master/texmf-dist/doc/latex/tabu/README b/Master/texmf-dist/doc/latex/tabu/README
index e3a81270baa..04d554ad065 100644
--- a/Master/texmf-dist/doc/latex/tabu/README
+++ b/Master/texmf-dist/doc/latex/tabu/README
@@ -9,6 +9,10 @@ not split accross pages.
 tabu is based on array.sty and requires no other package.
 tabu does not modify array.sty nor the classes of tokens.
 
+Starting from version 1.5, longtabu is provided: based on
+longtable, longtabu allows tabulars to stretch out on
+several pages.
+
 tabu can be used in place of tabular, tabular* and tabularx
 X columns in tabu can be specified with a width coefficient
 the alignement (l,r,c,j) the column type (p,m,b) or even $.
diff --git a/Master/texmf-dist/doc/latex/tabu/tabu.pdf b/Master/texmf-dist/doc/latex/tabu/tabu.pdf
index d0185d0ceee..ff38df7b257 100644
--- a/Master/texmf-dist/doc/latex/tabu/tabu.pdf
+++ b/Master/texmf-dist/doc/latex/tabu/tabu.pdf
diff --git a/Master/texmf-dist/source/latex/tabu/tabu.drv b/Master/texmf-dist/source/latex/tabu/tabu.drv
index 7ba3a4e3baa..6fe19b118d5 100644
--- a/Master/texmf-dist/source/latex/tabu/tabu.drv
+++ b/Master/texmf-dist/source/latex/tabu/tabu.drv
@@ -8,7 +8,7 @@
 %% 
 %% This is a generated file.
 %% 
-%% tabu : 2010/11/22 v1.4 - tabu : Flexible LaTeX tabulars
+%% tabu : 2010/12/07 v1.5 - tabu : Flexible LaTeX tabulars
 %% 
 %% This work may be distributed and/or modified under the
 %% conditions of the LaTeX Project Public License, either
@@ -25,8 +25,8 @@
 %% 
 \edef\thisfile{\jobname}
 \def\thisinfo{Flexible \LaTeX{} tabulars (\FC)}
-\def\thisdate{2010/11/22}
-\def\thisversion{1.4}
+\def\thisdate{2010/12/07}
+\def\thisversion{1.5}
 \def\CTANbaseurl{http://www.ctan.org/tex-archive/macros/latex}
 \def\CTANdisplay{CTAN:macros/latex}
 \makeatletter\protected\def\CTANhref{\@ifstar\CTANhrefstar\CTANhrefnost}\makeatother
@@ -40,14 +40,17 @@
 \AtBeginDocument{\DeleteShortVerb{\|}}
 \usepackage[latin1]{inputenc}
 \usepackage[T1]{fontenc}
-\usepackage{etoolbox,geometry,graphicx,xcolor,lastpage,lmodern,bbding,hologo,relsize,moresize,manfnt,xspace,numprint}
+\usepackage{etoolbox,geometry,graphicx,xcolor,lastpage,lmodern,bbding,hologo,relsize,moresize,manfnt,pifont,xspace,numprint,amsmath}
 \usepackage[official]{eurosym}
 \usepackage[expansion=all,stretch=20,shrink=60]{microtype}
-\usepackage{tocloft,titlesec,hypbmsec,fancyhdr,enumitem,multirow,makecell,booktabs,delarray,ragged2e,colortbl,marginnote,shapepar}
+\usepackage{tocloft,titlesec,hypbmsec,fancyhdr,enumitem,multirow,makecell,booktabs,delarray,ragged2e,colortbl,marginnote,shapepar,needspace}
 \heavyrulewidth=.7pt
 \usepackage{holtxdoc,bookmark}
-\usepackage{tabularx}
-\usepackage{interfaces}[2010/11/26]
+\usepackage{longtable}
+\usepackage{tabularx}\tracingtabularx
+\usepackage{enumitem-zref}
+\usepackage[verbose]{linegoal}[2010/12/07]
+\usepackage{interfaces}[2010/12/07]
 \usetikz{basic,chains,positioning}
 \usepackage{embedfile}
 \RequirePackage{amsopn,amsmath}% \DeclareMathOperator
@@ -60,14 +63,15 @@
 \csname endofdump\endcsname
 \CodelineNumbered
 \usepackage{fancyvrb}\fvset{gobble=1,listparameters={\topsep=0pt}}
-\usepackage[linegoal]{tabu}\tracingtabu\tracingtabularx
+\usepackage[linegoal]{tabu}\tracingtabu=2
+\tabulinestyle{dash=\hbox{$\mkern2mu\scriptscriptstyle\cdotp\mkern2mu$}}
 \lastlinefit999
 \geometry{top=0pt,includeheadfoot,headheight=.6cm,headsep=.6cm,bottom=.6cm,footskip=.5cm,left=4cm,right=1.5cm}
 \hypersetup{%
   pdftitle={tabu},
   pdfsubject={a simple line parser for TeX},
   pdfauthor={Florent CHERVET},
-  colorlinks,linkcolor=reflink,
+  colorlinks,linkcolor=reflink,urlcolor=CornflowerBlue,
   pdfstartview=FitH,pdfpagemode=UseOutLines,
   pdfkeywords={tex, e-tex, latex, package, tabular, array, halign, tabularx, longtable, color, colortbl, alignment},
   }
diff --git a/Master/texmf-dist/source/latex/tabu/tabu.dtx b/Master/texmf-dist/source/latex/tabu/tabu.dtx
index 804d8a60e75..8bef61f5657 100644
--- a/Master/texmf-dist/source/latex/tabu/tabu.dtx
+++ b/Master/texmf-dist/source/latex/tabu/tabu.dtx
@@ -1,5 +1,5 @@
 % \iffalse meta-comment
-% tabu : 2010/11/22 v1.4 - tabu: flexible LaTeX tabulars]
+% tabu : 2010/12/07 v1.5 - tabu: flexible LaTeX tabulars]
 %
 % This work may be distributed and/or modified under the
 % conditions of the LaTeX Project Public License, either
@@ -36,7 +36,7 @@
 \input docstrip.tex
 \Msg{************************************************************************}
 \Msg{* Installation}
-\Msg{* Package: 2010/11/22 v1.4 - tabu: Flexible LaTeX tabulars}
+\Msg{* Package: 2010/12/07 v1.5 - tabu: Flexible LaTeX tabulars}
 \Msg{************************************************************************}
 
 \keepsilent
@@ -47,7 +47,7 @@
 
 This is a generated file.
 
-tabu : 2010/11/22 v1.4 - tabu : Flexible LaTeX tabulars
+tabu : 2010/12/07 v1.5 - tabu : Flexible LaTeX tabulars
 
 This work may be distributed and/or modified under the
 conditions of the LaTeX Project Public License, either
@@ -70,7 +70,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \file{tabu.sty}{\from{tabu.dtx}{package}}%
 }
 
-\askforoverwritefalse
+\askforoverwritetrue
 \generate{%
    \file{tabu.drv}{\from{tabu.dtx}{driver}}%
 }
@@ -98,8 +98,8 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %<*driver>
 \edef\thisfile{\jobname}
 \def\thisinfo{Flexible \LaTeX{} tabulars (\FC)}
-\def\thisdate{2010/11/22}
-\def\thisversion{1.4}
+\def\thisdate{2010/12/07}
+\def\thisversion{1.5}
 \def\CTANbaseurl{http://www.ctan.org/tex-archive/macros/latex}
 \def\CTANdisplay{CTAN:macros/latex}
 \makeatletter\protected\def\CTANhref{\@ifstar\CTANhrefstar\CTANhrefnost}\makeatother
@@ -113,14 +113,17 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 \AtBeginDocument{\DeleteShortVerb{\|}}
 \usepackage[latin1]{inputenc}
 \usepackage[T1]{fontenc}
-\usepackage{etoolbox,geometry,graphicx,xcolor,lastpage,lmodern,bbding,hologo,relsize,moresize,manfnt,xspace,numprint}
+\usepackage{etoolbox,geometry,graphicx,xcolor,lastpage,lmodern,bbding,hologo,relsize,moresize,manfnt,pifont,xspace,numprint,amsmath}
 \usepackage[official]{eurosym}
 \usepackage[expansion=all,stretch=20,shrink=60]{microtype}
-\usepackage{tocloft,titlesec,hypbmsec,fancyhdr,enumitem,multirow,makecell,booktabs,delarray,ragged2e,colortbl,marginnote,shapepar}
+\usepackage{tocloft,titlesec,hypbmsec,fancyhdr,enumitem,multirow,makecell,booktabs,delarray,ragged2e,colortbl,marginnote,shapepar,needspace}
 \heavyrulewidth=.7pt
 \usepackage{holtxdoc,bookmark}
-\usepackage{tabularx}
-\usepackage{interfaces}[2010/11/26]
+\usepackage{longtable}
+\usepackage{tabularx}\tracingtabularx
+\usepackage{enumitem-zref}
+\usepackage[verbose]{linegoal}[2010/12/07]
+\usepackage{interfaces}[2010/12/07]
 \usetikz{basic,chains,positioning}
 \usepackage{embedfile}
 \RequirePackage{amsopn,amsmath}% \DeclareMathOperator
@@ -133,14 +136,15 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 \csname endofdump\endcsname
 \CodelineNumbered
 \usepackage{fancyvrb}\fvset{gobble=1,listparameters={\topsep=0pt}}
-\usepackage[linegoal]{tabu}\tracingtabu\tracingtabularx
+\usepackage[linegoal]{tabu}\tracingtabu=2
+\tabulinestyle{dash=\hbox{$\mkern2mu\scriptscriptstyle\cdotp\mkern2mu$}}
 \lastlinefit999
 \geometry{top=0pt,includeheadfoot,headheight=.6cm,headsep=.6cm,bottom=.6cm,footskip=.5cm,left=4cm,right=1.5cm}
 \hypersetup{%
   pdftitle={tabu},
   pdfsubject={a simple line parser for TeX},
   pdfauthor={Florent CHERVET},
-  colorlinks,linkcolor=reflink,
+  colorlinks,linkcolor=reflink,urlcolor=CornflowerBlue,
   pdfstartview=FitH,pdfpagemode=UseOutLines,
   pdfkeywords={tex, e-tex, latex, package, tabular, array, halign, tabularx, longtable, color, colortbl, alignment},
   }
@@ -151,7 +155,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %</driver>
 % \fi
 %
-% \CheckSum{3666}
+% \CheckSum{4463}
 %
 % \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
@@ -170,7 +174,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %   Right brace   \}     Tilde         \~}
 %
 % \DoNotIndex{\begin,\CodelineIndex,\CodelineNumbered,\def,\DisableCrossrefs,\~,\@ifpackagelater,\z@,\@ne,\@@}
-% \DoNotIndex{\DocInput,\documentclass,\EnableCrossrefs,\end,\GetFileInfo}
+% \DoNotIndex{\DocInput,\documentclass,\EnableCrossrefs,\end,\GetFileInfo,\TMP@EnsureCode}
 % \DoNotIndex{\NeedsTeXFormat,\OnlyDescription,\RecordChanges,\usepackage}
 % \DoNotIndex{\ProvidesClass,\ProvidesPackage,\ProvidesFile,\RequirePackage}
 % \DoNotIndex{\filename,\fileversion,\filedate,\let}
@@ -193,13 +197,11 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \DoNotIndex{\p@,\tracingtabu,\@ne,\tw@,\m@ne,\z@skip}
 % \makeatletter
 % \newrobustcmd\ClearPage{\@ifstar\clearpage{}}
+% \providecommand\lsstyle{}
 % \makeatletter
 % \catcode`\§ \active   \def§{\@ifnextchar §{\par\nobreak\vskip-2\parskip}{\par\nobreak\vskip-\parskip}}
-% \def\thispackage{\xpackage{{\pkgcolor\thisfile}}\xspace}
-% \def\ThisPackage{\Xpackage{\thisfile}\xspace}
-% \def\Xpackage{\@dblarg\X@package}
-% \def\X@package[#1]#2{\@testopt{\X@@package{#1}{#2}}{}}
-% \def\X@@package#1#2[#3]{\xpackage{#2\footnote{\noindent\xpackage{#2}: \CTANhref{#1}#3}}}
+% \def\thispackage{\xpackage{{\pkgcolor\thisfile}}\Xspace}
+% \def\Xpackage#1{\href{http://www.ctan.org/tex-archive/help/Catalogue/entries/#1.html}{\xpackage{#1}}}
 % \def\Underbrace#1_#2{$\underbrace{\vtop to2ex{}\hbox{#1}}_{\footnotesize\hbox{#2}}$}
 %\def\FV@DefineCommandChars #1#2#3{%
 %   \edef\FV@restoreCommandChars{%
@@ -220,6 +222,19 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \DefineVerbatimEnvironment{VerbLines*}{Verbatim}{frame=lines,framesep=6pt,fontfamily=\ttdefault,fontseries=m,commandchars=$()}
 % \DefineVerbatimEnvironment{Verb}{Verbatim}{fontfamily=\ttdefault,fontseries=m}
 % \DefineVerbatimEnvironment{Verb*}{Verbatim}{fontfamily=\ttdefault,fontseries=m,commandchars=$()}
+% \renewrobustcmd*\mathversion[1]{^^A
+%  \expandafter\ifx\csname mv@#1\endcsname\relax
+%     \@latex@error{Math version `#1' is not defined}\@eha
+%  \else \edef\math@version{#1}\gdef\glb@currsize{}\aftergroup\glb@settings
+%        \ifmmode \check@mathfonts \fi
+%  \fi
+% }
+% \newrobustcmd*\OR{{\,\upshape\texttbf\textbar\,}}
+% \newrobustcmd*\CheckOK{{\scriptsize\textcolor{ForestGreen}\CheckmarkBold}}
+% \newrobustcmd*\CheckFAIL{{\scriptsize\textcolor{Crimson}\XSolidBrush}}
+% \newcommand\tikzlabel[2][]{\tikz[{remember picture,#1}]\coordinate ({#2});\ignorespaces}
+% \newlist{itempunct}{itemize}{1}
+% \setlist[itempunct]{nolistsep,font=\smaller,leftmargin=1.7em,label=\textbullet}
 % \def\smex{\leavevmode\hb@xt@2em{\hfil$\longrightarrow$\hfil}}
 % \def\ttdefault{lmvtt}
 % \renewrobustcmd\#[1]{{\usefont{T1}{pcr}{bx}{n}\char`\##1}}
@@ -259,25 +274,28 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % }
 % \renewrobustcmd\declcs[2][]{^^A
 %   \par\addvspace\parskip
-%   \goodbreak
-%   \noindent\larger\changefont{spread=1}^^A
+%   \needspace{\bottomtitlespace}%
+%   \noindent\changefont{size+=2.5pt,spread=1,fam=\ttdefault}^^A
 %   \hspace{-\leftmargini}^^A
 %   \def\*{\unskip\,\texttt{*}}^^A
-%   \begin{tabular}{|l|}^^A
+%   \begin{tabu}{|l|}^^A
 %     \hline
 %     \expandafter\SpecialUsageIndex\csname #2\endcsname
-%     \raisedhyperdef[8pt]{declcs}{#2}{\cs[{#1}]{#2}}^^A
+%     \raisedhyperdef[14pt]{declcs}{#2}{\cs[{#1}]{#2}}^^A
 % }^^A
 % \renewcommand\enddeclcs{%
 %     \crcr \hline
-%     \end{tabular}%
+%     \end{tabu}%
 %     \nobreak   \par  \nobreak
 %     \noindent
 %     \ignorespacesafterend
 %  }
-% \def\declmargin{\hspace*{\dimexpr-\leftmargini+\arrayrulewidth+\tabcolsep}}
+% \newrobustcmd*\csref[2][]{\hyperref{}{declcs}{#2}{\cs[{#1}]{#2}}}
+% \def\declmargin{\hspace*{\declmarginwidth}}
+% \def\declmarginwidth{\dimexpr-\leftmargini+\arrayrulewidth+\tabcolsep}
 % \pretocmd\textasteriskcentered{\usefont{OMS}{cmsy}mn}{}{}
-% \bookmarksetup{open=true,openlevel=3}
+% \newrobustcmd*\abs[1]{\left\lvert#1\right\rvert}
+% \bookmarksetup{open=true,openlevel=2}
 % \pagesetup{%
 %  head/rule/width=.0pt,
 %  left/offset=3cm,foot/left/offset+=.5cm,right/offset=1cm,
@@ -296,9 +314,10 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %  foot/left=\vbox to\baselineskip{\vss{{\rotatebox[origin=l]{90}{\thispackage\,[rev.\thisversion]\,\copyright\,\thisyear\,\lower.4ex\hbox{\pkgcolor\NibRight}\,\FC\quad \xemail{florent.chervet at free.fr}}}}},
 % }
 % \pagestyle{fancy}
+% \bottomtitles=.15\textheight
 % \sectionformat\section{
 %        mark=\marksthe{section}{#1},
-%        left=\dimexpr-\leftmargini+\arrayrulewidth+\tabcolsep\relax,
+%        left=\declmarginwidth,
 %        top=\medskipamount,
 %        bottom=\smallskipamount,
 %        font=\normalfont\Large\bfseries,
@@ -307,6 +326,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \sectionformat\subsection{%
 %     top=\medskipamount,
 %     bottom=.5\smallskipamount,
+%     left=.5\declmarginwidth,
 %     bookmark={color=[rgb]{0.02,0.05,.1}},
 %     font=\normalfont\Large\bfseries,
 %     break=\addpenalty{-\@highpenalty}}
@@ -317,76 +337,81 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %     top=\medskipamount,
 %     bottom=.5\smallskipamount,
 %     break=\addpenalty{-\@medpenalty}}
-% \setitemize{itemsep=\parskip,topsep=0pt,labelsep=1em,parsep=0pt}
+% \setitemize{itemsep=\parskip,topsep=0pt,labelsep=1em,parsep=0pt,beginpenalty=10000}
 % \tikzset{every picture/.add style={}{/utils/exec=\changefont{spread=1}}}
 % \newrobustcmd*\IMPLEMENTATION{%
-%     \newgeometry{top=0.8cm,headheight=.5cm,headsep=.3cm,bottom=1.2cm,footskip=.5cm,left=5cm,right=.50cm}
+%     \newgeometry{top=0.8cm,headheight=.5cm,headsep=.3cm,bottom=1.2cm,footskip=.5cm,left=5cm,right=.5cm}
 %     \pagesetup*{
 %        left/offset+=1cm,right/offset-=1cm,
 %        head/left=\moveleft1cm\vbox to\z@{\vss\setbox0=\null\ht0=\z@\wd0=\paperwidth\dp0=\headheight\rlap{\colorbox{GhostWhite}{\box0}}}\vskip-\headheight t\,a\,b\,u\,\ \ i\,m\,p\,l\,e\,m\,e\,n\,t\,a\,t\,i\,o\,n,
 %      }%
 %     \clearpage
 %     \sectionformat\section{bookmark/color=black}\sectionformat\subsection{bookmark/color=black}
-%     \bookmarksetup{bold*,openlevel=3}
+%     \bookmarksetup{bold*,openlevel=3} \hfuzz=3mm
 %     \section(Implementation)[\mdseries\scshape\pmb{Implementation}]{Implementation} \label{sec:implementation}}
 % \let\plainllap\llap
 % \newrobustcmd\macro@llap[1]{\global\let\llap\plainllap\setbox0\hbox{#1}^^A
-%  \ifdim\wd0>4cm\hbox to\z@{\hss\hbox to4cm{#1\hss}}^^A
-%        \edef\@tempa{\the\everypar\hskip\dimexpr\the\wd0-4cm\relax\global\everypar{}}%
+%  \ifdim\wd0>4.4cm\hbox to\z@{\hss\hbox to4.4cm{#1\hss}}^^A
+%        \edef\@tempa{\the\everypar\hskip\dimexpr\the\wd0-4.4cm\relax\global\everypar{}}%
 %            \global\everypar\expandafter{\@tempa}^^A
 %  \else\hbox to\z@{\hss#1}\fi
 %  \setbox\z@\box\voidb@x}
-% \pretocmd\macro{\MacrocodeTopsep=\z@skip\MacroTopsep\z@skip\let\llap\macro@llap\parsep=\z@\topsep=\z@\itemsep=\z@\partopsep\z@}{}{}
+% \pretocmd\macro{\needspace{2\baselineskip}\MacrocodeTopsep=\z@skip\MacroTopsep\z@skip\let\llap\macro@llap\parsep=\z@\topsep=\z@\itemsep=\z@\partopsep\z@}{}{}
 % \apptocmd\endmacro{\goodbreak\vskip.3\parskip}{}{}
 %
-% \definecolor{reflink}{rgb}{0.95,0.00,0.05}
-% \definecolor{reflink}{rgb}{0.05,0.00,0.95}
+% \colorlet{reflink}{DarkSlateBlue}
 % \newrobustcmd*\stform{\ifincsname\else\expandafter\@stform\fi}
 % \newrobustcmd*\@stform{\@ifnextchar*{\@@stform[]\textasteriskcentered\@gobble}\@@stform}
-% \newrobustcmd*\@@stform[2][\string]{\textttbf{#1#2}\ifnum\catcode`\ =\active\else\expandafter\xspace\fi}
+% \newrobustcmd*\@@stform[2][\string]{\textttbf{#1#2}\Xspace}
+% \newrobustcmd\Xspace{\ifnum\catcode`\ =\active\else\expandafter\xspace\fi}
+%
 %
 % \makeatother
 %
 %
 % \deffootnote{1em}{0pt}{\rlap{\textsuperscript{\thefootnotemark}}\kern1em}
 %
-% \title{\vspace*{-28pt}\mdseries {\HUGE\bfseries\sffamily t\,a\,b\,u\,}}
+% \title{\vspace*{-28pt}\mdseries {\HUGE\bfseries\sffamily t\,a\,b\,u\,}\vspace*{6pt}}
 % \date{}
 % \author{\small\thisdate~--~version \thisversion}
-% \subtitle{\LARGE Flexible \LaTeX{} tabulars\endgraf {\small\FC}}
+% \subtitle{\begin{tabu}{X[c]} tabu\, and\, longtabu \\[1ex] \LARGE Flexible \LaTeX{} tabulars\\ \small\FC \end{tabu}\vspace*{-12pt}}
 % \maketitle
 %
-%
-%
-% \makeatletter\begingroup\let\@thefnmark\@empty\let\@makefntext\@firstofone
+% {\makeatletter\let\@thefnmark\@empty\let\@makefntext\@firstofone
 % \footnotetext{\noindent\parskip=0pt\scriptsize
-% This documentation is produced with the +DocStrip+ utility. Package \xpackage{tabu} is used with the \textt{linegoal} option.\topsep=0pt
-% \begin{tabbing}
-% \qquad\=\smex\=To get the documentation, \= run (thrice):\quad\= \texttt{pdflatex \thisfile.dtx} \\
-% \qquad\>\>To get the index, \> run:\>\texttt{makeindex -s gind.ist \thisfile.idx} \\
-% \>\smex\>To get the package, \> run:\>        \texttt{etex \thisfile.dtx}
-% \end{tabbing}§
-% The \xext{dtx} file is embedded into this pdf file thank to \xpackage{embedfile} by H. Oberdiek.}
-% \endgroup\makeatother
+% This documentation is produced with the \textt{DocStrip} utility, and required \thispackage with its \textt{linegoal} option.\par
+% \begin{tabu}{X[-3]X[-1]X}
+% \smex To get the package,                   &run:          &\texttt{etex \thisfile.dtx}                  \\
+% \smex To get the documentation              &run (thrice): &\textt{pdflatex \thisfile.dtx}               \\
+% \leavevmode\hphantom\smex To get the index, &run:          &\texttt{makeindex -s gind.ist \thisfile.idx}
+% \end{tabu}§
+% The \xext{dtx} file is embedded into this pdf file thank to \Xpackage{embedfile} by H. Oberdiek.}
+% }
 %
 % \deffootnote{1em}{0pt}{\rlap{\thefootnotemark.}\kern1em}
 %
-% {\let\quotation\relax\vspace*{-1cm}%
-% \begin{abstract}\parskip\medskipamount\parindent0pt\lastlinefit0\leftskip1cm\rightskip\leftskip
+% {\let\quotation\relax\let\endquotation\relax\vspace*{-1cm}%
+% \begin{abstract}\parskip\smallskipamount\parindent0pt\lastlinefit0\leftskip.7cm\rightskip\leftskip
 %
 % This package defines a single environment \textt{tabu} to make all kinds of tabulars in text or in math mode
 % provided that they do not split across pages.
 %
-% \textt{tabu} is more flexible that \textt{tabular}, \textt{tabular*}, \textt{tabularx}
-% and \textt{array} and extends the possibilities. All tabulars in this document were made
-% with the \textt{tabu} environment. Last (but not least) \textt{tabu} is more than compatible
-% with any package that provides commands to format tabulars.
-% Indeed, \thispackage{} \textbf{does not modify any of the macros of \xfile{array.sty}.} All
-% functionalities are obtained with only two modifications\footnote{\cs{prepnext@tok} and \cs{save@decl}.
-% See ``\nameref{sec:light package option}''.} which are loaded only inside
-% a \textt{tabu} environment.
+% Starting from version 1.5, the environment \textt{longtabu} is provided to make tabulars that can stretch out
+% on several pages. \textt{longtabu} works like \textt{tabu} and is defined only if the package
+% \Xpackage{longtable} is loaded.
 %
-% \xpackage{tabu} requires \eTeX, the standard package \xfile{array.sty} and no other package.
+% \textt{tabu} is more flexible that \textt{tabular}, \textt{tabular*}, \textt{tabularx}
+% and \textt{array} and extends the possibilities.  All tabulars in this document were made
+% with the \textt{tabu} environment. Widths computations for \textt{tabu X} columns is
+% \refitem{item:convergence optimisation}[optimised] compared to \Xpackage{tabularx} implementation.
+% Last (but not least) \textt{tabu} is fully compatible with any package that provides commands
+% to format tabulars. Indeed, \textt{tabu} does not modify any of the macros of \xfile{array.sty}.
+%
+% \thispackage requires \eTeX{} and the standard package \xfile{array.sty}. Natural widths of columns
+% are computed by (but not printed by) the code of \Xpackage{varwidth} by D. Arseneau (for the cases of
+% \hyperref[X columns with tabu spread]{\textt X columns in \textt{tabu spread}} and
+% \refitem{tabu X columns,2}[negativ width coefficients]\footnote{The documentation is compiled with
+% \hyperref[enumitem-zref]{\xpackage{enumitem-zref}}}). Finally \textt{longtabu} is based on \textt{longtable}.
 %
 % \end{abstract}}
 %
@@ -415,39 +440,128 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % }
 %
 % \clearpage
+% \begingroup
+% ^^A\geometry{top=0pt,includeheadfoot,headheight=.6cm,headsep=.6cm,bottom=.6cm,footskip=.5cm,left=4cm,right=1.5cm}
+% \newgeometry{top=0pt,includeheadfoot,headheight=.6cm,headsep=.6cm,bottom=.6cm,footskip=.5cm,left=1.5cm,right=1cm}
+% \pagesetup*{left/offset-=2.5cm,right/offset-=.5cm}
+%
 % \changefont{spread*=1.1}
+% \phantomsection\label{Summary}
+% \addcontentsline{toc}{section}{Summary of the features provided by \textt{tabu}}
+% \def\arraystretch{1.1}\enlargethispage\baselineskip\vspace*{-6mm}
+% \begin{tabu}{>{\ttfamily\bfseries}X[-1]X} \toprule
+% \rowfont{\larger\bfseries\lsstyle}
+% \multicolumn2c{Summary of the features provided by \xpackage{tabu}} \\ \tabucline[dash]-
+% \hyperref[sec.tabu]{tabu} &
+%    is like \textt{tabular} in text mode and like \textt{array} in math mode when there is no
+%    \textt X column in its preamble
+% \\
+% \hyperref[sec.longtabu]{longtabu} &
+%    is like \textt{longtable} with the possibility to use \textt{tabu X} columns and vertical lines
+%    with the extended syntax.
+% \\
+% \hyperref[Vertical lines]{\texttbf\textbar[width,color]} &
+%    vertical lines have an optional parameter.
+% \\
+% \M*{tabu} to \meta{dimen} &
+%    specifies the target width of the whole tabular. This is like \textt{tabular\textasteriskcentered}\,
+%    with an automatic stretchability that can be overwritten with \textt{@\M*{\cs{extracolsep}\M*{dimen}}}
+%    in front of the preamble.
+% \\
+% \M*{tabu} spread \meta{dimen} &
+%    has no equivalent in \LaTeX: the final width is \meta{dimen} wider than the
+%    natural width that can be obtained with \textt{spread 0pt}.
+% \\ \tabucline[dash]-
+% \hyperref[tabu X columns]{X[coef,align,type]} \par X[coef,align,type,\$] &
+%    \textt X columns widths are adjusted in order for the whole tabular to fit the
+%    target width. The target width is a dimension either:
+%    \begin{itempunct}[label=\ding{223}]
+%    \item directly specified with \textt{\M*{tabu} to\meta{dimen}}
+%    \item computed from the natural width: \textt{\M*{tabu} spread\meta{dimen}}
+%    \item by default \cs{linewidth} (or \cs{linegoal} with the \textt{linegoal} package option).
+%    \end{itempunct}
+%    \textt{coef} scales the widths of the \textt X columns, if there are more than one \textt X column. \par
+%    \textt{align} is either \textt r, \textt c, \textt l\, or\, \textt j\, and \textt{type}\, can be \textt p (default), \textt m\, or\, \textt b. \par
+%    \textt{X[\$]}\, makes a math \textt X column (\ie \textt{>\M*{\$}X<\M*{\$}})
+% \\
+% \refitem{tabu X columns,2}[{X[$-$coef,align,type]}] &
+%    \textt X columns widths are first computed with the absolute value: $\mathversion{bold}\abs{\textt{coef}}$.\par
+%    Then the width is made narrower down to the natural width of the column if possible.\par
+%    In any case, the final width does not exceed the one obtained with \textt{X$\mathversion{bold}\left[\abs{\textt{coef}}\right]$}. \par
+%    The final \textt{tabu} can be narrower than its \textt{target} if:
+%    \begin{itempunct}
+%    \item all \textt{coefs} are negativ,\, and
+%    \item no target has been specified (\ie the default target is used).
+%    \end{itempunct}
+%    In this case, \textt{tabu} behaves as if it was said:\, \textt{\M*{tabu} spread 0pt}.
+% \\ \tabucline[dash]-
+% \csref{savetabu}\M*{user-name} &
+%    Saves the \textt{tabu} preamble and its parameters. \par
+%    The command must appear at the end of a line: after \string\\\ or \cs{hline}.
+% \\
+% \csref{usetabu}\M*{user-name} &
+%    Makes a \textt{tabu} of exactly the same shape as the one saved with \cs{savetabu}.
+%    All parameters (\textt{target}, \textt{preamble}, \textt{stretch} \etc) are restored.\par
+%    This command is put alone in the preamble in place of the columns specifications.
+% \\
+% \csref{preamble}\M*{user-name} &
+%    Makes a \textt{tabu} with the same preamble as the one saved with \cs{savetabu}.\par
+%    The \textt{preamble} only is restored, not the \textt{target} nor any other parameter.\par
+%    This command is put alone in the preamble in place of the columns specifications.
+%    \\ \tabucline[dash]-
+% \csref{tabuphantomline} & inserts a phantom (\ie invisible) line inside the \textt{tabu}\par
+%    May be usefull with \cs{multicolumn} in some cases.
+%    \\ \tabucline[dash]-
+% \csref{tabucline}\M*[spec]\M*{start-stop} & Draws a line comparable to \cs{hline}. The line \meta{spec} can contain
+%              information for making a dash or dotted line (f.ex. \M*[on 3pt off 6pt]) and a color name.\par
+%              The line spec can also be defined with \cs{tabulinestyle}
+%     \\
+% \csref{tabulinestyle}\M*{name=spec,...} & Defines a line style for use with \cs{tabucline}
+% \\ \bottomrule
+% \end{tabu}
+%
+% \textbf\textbar\, \textt{X}\, \cs{usetabu}\, and\, \cs{preamble} are defined as new column types loaded
+% only inside the \cs{@mkpream} group inside the \textt{tabu} environment.
+% 
+%
+% \clearpage
+% \endgroup
 %
-% \bottomtitles=.3\textwidth
+% \setitemize{leftmargin=3em}
 % \section{The \textt{tabu} environment}
 % \label{sec.tabu}
 %
+%
 % \subsection(tabu, tabu to, tabu spread){\textt{tabu}, \textt{tabu to} and \textt{tabu spread}}
 %
 % {\let\red\relax
-% \begin{declcs}{begin}\M*{\red tabu}\M[pos]\M{tabular preamble} \\
-% \cs{begin}\M*{{\red tabu}} to \meta{dimen}\M[pos]\M{tabular preamble} \\
-% \cs{begin}\M*{{\red tabu}} spread \meta{dimen}\M[pos]\M{tabular preamble} \\
+% \begin{declcs}{begin}\M*{tabu} \M*[pos] \M*{tabular preamble} \\
+% \cs{begin}\M*{tabu} to \meta{dimen} \M*[pos] \M*{tabular preamble} \\
+% \cs{begin}\M*{tabu} spread \meta{dimen} \M*[pos] \M*{tabular preamble} \\
 % \end{declcs}}
 %
 % The \textt{tabu} environment behaves exactly like \textt{tabular}: the preamble
-% is parsed by the macros in \xfile{array.sty} with no modification in the characters classes.
+% is parsed by the macros in \xfile{array.sty} with no modification.
 %  \textt{tabu} improves \textt{tabular} and \textt{array}:
 %  \begin{itemize}
-%  \item footnotes and index words are allowed inside \textt{tabu}, unlike \xpackage{tabularx}, footnote links
+%  \item \textbf{footnotes} and index words are allowed inside \textt{tabu}, unlike \xpackage{tabularx}, footnote links
 %        are not broken when compiled with \xpackage{hyperref}. The syntax \cs{footnote}\M[number]\M{text}
-%        is allowed (this is not implemented for \xpackage{longtable} yet...)
-%  \item \textt X columns are also allowed, with an \emph{optional} parameter for the width-coefficient,
-%        the alignment (\textt{l,r,c} or \textt{L,R,C} for \xpackage{ragged2e} settings) and the column
-%        type (\textt{p,m,b}). \textt{tabu} has also a \emph{default target width} when used
-%        with \textt X columns.
+%        is allowed in \textt{tabu} and \textt{longtabu} (this is not implemented for \xpackage{longtable} yet...)
+%  \item \textt X columns are implemented with an \emph{optional} parameter for the \textbf{width-coefficient}
+%        (which can be \refitem{item:Negativ width coefficients}[negativ]: see next section),
+%        the \textbf{alignment} (\textt r, \textt c, \textt l, or \textt j, and \textt R, \textt C, \textt L or \textt J
+%        for \xpackage{ragged2e} settings) and
+%        the \textbf{column type} (\textt p, \textt m, or \textt b). \\
+%        \textt{tabu} has a \refitem{item:default target width}[default target width] when used with \textt X columns,
+%        making nesting even easier.
 %  \item You are used to the \textt{tabular} environment in text mode, and \textt{array} in math mode,
 %        but \textt{tabu} works in both modes and its name does not change... \textt X columns are also
 %        possible in math mode; \xpackage{delarray} shortcuts for delimiters are available in both math and text modes.
-%  \item a \textt{tabu} environment can contain another tabular of any kind: \textt{tabular}, \textt{tabular\stform*},
+%  \item A \textt{tabu} environment can contain another tabular of any kind: \textt{tabular}, \textt{tabular\stform*},
 %        \textt{tabularx} or \textt{tabu} itself can be placed in any cell of a \textt{tabu}. Conversely,
 %        \textt{tabu} can be placed in a \textt{tabular}, \textt{tabularx} \etc.
-%  \item \textt{tabu} introduces optional parameters to columns specifications, providing facilities
-%         for modifying columns or line widths, inserting verbatim text...
+%  \item \textt{tabu} provides facilities for \hyperref[Lines inside tabu]{vertical and horizontal lines},
+%        and for the insertion of \hyperref[Verbatim inside tabu]{verbatim text} inside \textt X columns.
 %  \item \textt{tabu} is more than compatible with \xpackage{arydshln} (for dashed and dotted lines)
 %        and \xpackage{colortbl}: actually some corrections of those packages are loaded as soon as you
 %        enter a \textt{tabu} environment. Compatibility with \xpackage{delarray}, \xpackage{hhline},
@@ -462,7 +576,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 % \declmargin \cs{begin}\M*{tabu} \textt{to}\meta{dimen} is like \textt{tabular\textasteriskcentered} but the inter-columns space is
 % given a stretchability of 1fil, in other words \textt{@\M*{\cs{extracolsep}\M*{0pt plus 1fil}}}
-% is inserted by default at the beginning of the tabular preamble, unless you specify another value for \cs{extracolsep}. Therefore
+% is inserted by default at the beginning of the tabular preamble, unless another value for \cs{extracolsep} is specified. Therefore
 % ``\textt{tabu to}'' fills in width the specified \meta{dimen}.
 %
 % \bigskip
@@ -470,27 +584,72 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \declmargin \cs{begin}\M*{tabu} \textt{spread}\meta{dimen} does a tabular whose width is \meta{dimen} wider than its natural width.
 % \textt{@\M*{\cs{extracolsep}\M*{0pt plus 1fil}}} is inserted by default if \meta{dimen}$>0$.
 %
+% \subsection{\textt{longtabu}, \textt{longtabu to} and \textt{longtabu spread}}
+% \label{sec.longtabu}
+%
+% \begin{declcs}{begin}\M*{longtabu}\,\M*[l\OR c\OR r]\,\M*{tabular preamble} \\
+%   \cs{begin}\M*{longtabu} to \meta{dimen}\,\M*[l\OR c\OR r]\,\M*{tabular preamble} \\
+%   \cs{begin}\M*{longtabu} spread \meta{dimen}\, \M*[l\OR c\OR r]\,\M*{tabular preamble}
+% \end{declcs}
+%
+% \textt{longtabu} is just like \textt{tabu} but page breaks are allowed between rows of the table.
+% \textt{longtabu} is based on the \Xpackage{longtable} package which must be loaded, and all features
+% of the \textt{longtable} environment  works inside \textt{longtabu}: \cs{endhead}, \cs{endfirsthead},
+% \cs{endfoot}, \cs{endlastfoot} and \cs{caption}.
+%
+% \textt{longtabu} enhances the possibilities of \textt{longtable} with the possibility to use \textt{X columns}
+% and line specification for \hyperref[Vertical lines]{vertical rules}. \textt{longtabu} is thus much easier than
+% \Xpackage{ltxtable}.
+%
+% The following commmands provided for \textt{tabu} does not work with \textt{longtabu}:
+%
+% \let\theadfont\bfseries
+% \begin{longtabu}{X[-1]*2{X[-1c]}X} \toprule
+% \rowfont[c]{\bfseries} \textt{tabu} command &\thead{Not   \\available}          &\thead{Not                                                                     \\implemented} &Comment \\\tabucline[dash]-
+% \csref{tabucline}                           &             &\AsteriskRoundedEnds &\cs{tabucline} does not care of page breaks presently: use \cs{hline} instead. \\
+% \csref{usetabu}                             &\CheckFAIL   &                     &but \csref{savetabu} and \csref{preamble} work.                                \\
+% \hyperref[sec.math mode]{mathematical mode} &\CheckFAIL   &                     &\textt{longtable} is not designed to work in math mode.                        \\
+% \xpackage{delarray} shortcuts               &\CheckFAIL   &                     &a delimiter cannot be spanned over pages...                                    \\
+% \csref{tabuphantomline}                     &\CheckFAIL   &                     &useless inside \textt{longtabu}                                                \\
+% \\\bottomrule
+% \end{longtabu}
+%
+% However, \textt{tabu X} columns, \csref{rowfont}, \csref{verbatim} and \csref{tabudecimal} work inside \textt{longtabu}.
+%
 %
 % \subsection{\textt{tabu X} columns}
+% \label{tabu X columns}
 %
-% \textt{tabu X} columns can be viewed as an enhancement of \xpackage{tabularx} \textt X columns:
-% \begin{itemize}
-% \item width coefficients can optionally be given to \textt X columns\\
-%       ex.\, \textt{X[2.5]X[1]}\, is the same as\, \textt{X[2.5]X}\, and the same as\, \textt{X[5]X[2]} \\
+% \textt{tabu X} columns can be viewed as an enhancement of \xpackage{tabularx} \textt X columns, but do not interact
+% with them, for they are defined only for a short time during the parsing of the preamble:
+% \begin{itemize}[name=tabu X columns]
+% \item \textbf{width coefficients} can optionally be given to \textt X columns\\
+%       ex.\, \texttbf{X[2.5]X[1]}\, is the same as\, \texttbf{X[2.5]X}\, and the same as\, \texttbf{X[5]X[2]} \\
 %       This means that the first \textt X column will be two and a half wider than the second one or
 %       that the first \textt X column width will be \sfrac{5}{7} of the whole tabular width. \\[.5\baselineskip]
-%       \begin{tabu}{|X[c,2.5]|X[c]|} \firsthline \textt{X[2.5]} & \textt X \\ \hline\end{tabu}
-%       \pagebreak
-% \item horizontal alignment specification is made easier with\, \textt{X[5,r]X[2,c]}\, for example. Vertical
+%       \begin{tabu}to\linewidth{|X[c,2.5]|X[c]|} \firsthline \textt{X[2.5]} & \textt X \\ \hline\end{tabu}
+% \item \textbf{negativ width coefficients} \label{item:Negativ width coefficients} can be given to \textt X columns: \\
+%       ex.\, \texttbf{X[-2.5]X[1]}\,  or\, \texttbf{X[-2.5]X} \, or\, \texttbf{X[-5]X[2]} \\
+%       In this case, the first \textt X column will be \textitbf{at most} two and a half wider than the second one,
+%       and if the \emph{natural width} of the first \textt X column is finally less than
+%       $2.5 \times \left(\text{the width of the second column}\right)$ then it will be narrowed down to this natural width.
+%       \textbf{The following \textt{tabu}{\smaller s} have the same preamble:} \\
+%       \hspace*{1em}\cs{begin}\M*{tabu} to\cs{linewidth}\M*{|X\M*[$-$2.5c]|X\M*[c]|}: \\
+%       \begin{tabu} to\linewidth{|X[c,-2.5]|X[c]|} \firsthline \textt{X[$-$2.5]} & \textt X \\ \hline\end{tabu} \\
+%       \begin{tabu} to\linewidth{|X[c,-2.5]|X[c]|} \firsthline
+%       Negativ coefficients make \textt X columns close to standard\par \textt l, \textt c and \textt r columns.
+%                 & \textt X \\ \hline
+%       \end{tabu}
+% \item horizontal alignment specification is made easier with\, \texttbf{X[5,r]X[2,c]}\, for example. Vertical
 %       alignment can be specified as well with\, \textt{X[5,r,m]X[2,p,c]}\, (commas are not required,
 %       but \textt{X[2cm]} or \textt{X[4pc]} could be misunderstood -- not by \TeX{}: by you...).\\
-%       \begin{tabu}{X[c]X[4c]c}
+%       \begin{tabu}to \linewidth{X[-2c]X[c]c}
 %       \rowfont{\bfseries\ttfamily} Modifier & Meaning & Default \\
-%       \textt l, \textt c, \textt r, \textt j  & left, centered, right, justified  & \textt j \\
+%       \textt l, \textt c, \textt r, \textt j, \textt L, \textt C, \textt R, \textt J  & left, centered, right, justified  & \textt j \\
 %       \textt p, \textt m, \textt b &  \textt X column is converted into \textt p, \textt m or \textt b column & \textt p \\
 %       \$                      & \textt{X[\$]} is a shortcut for:\, \textt{>\M*{\$}X<\M*{\$}} & \\
 %       \end{tabu}
-% \item \textt{tabu X} columns can be spanned with \cs{multicolum} without any restriction.
+% \item \textt{tabu X} columns can be spanned with \cs{multicolum}.
 % \item \textt{tabu X} columns can be used with ``\textt{tabu spread}'' for small tabulars.
 % \item \textt{tabu X} columns can contain any type of \textt{tabular}, \textt{tabular*}, \textt{tabularx} or \textt{tabu}
 %       without special care about the syntax. \textt{tabu} can also be put inside \textt{tabular}, \textt{tabular*}
@@ -501,24 +660,28 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \item The ``algorithm'' (or the arithmetic) to get the target width for \textt{tabu X} columns is the same as the one
 %       used by \xpackage{tabularx}. \cs{hfuzz} is the ``tolerance'' for the whole tabular width. We use \eTeX{} \cs{dimexpr}
 %       instead of \TeX{} primitives (with round/truncate bias correction).
-% \item Convergence to the target width is optimized: the \cs{halign} preamble is not re-built at each trial, but only expanded again,
+% \item \label{item:convergence optimisation} Convergence to the target width is optimised:
+%       the \cs{halign} preamble is not re-built at each trial, but only expanded again,
 %       until the target is reached. Though optimized, the process is the same as the one implemented for \textt{tabularx}
-%       and in particular the content of the \textt{tabu} environment is collected as soon as a \textt{tabu X} column is found in the preamble.
-%       This implies restrictions on catcode modifications and verbatim text inside a \textt{tabu} with \textt X columns.
-% \item If the width of the whole tabular is not specified with ``\textt{tabu to}'' it is considered to be \cs{linewidth}.
+%       and in particular the content of the \textt{tabu} environment is collected as soon as a \textt{tabu X} column
+%       is found in the preamble. This implies restrictions on catcode modifications and verbatim text inside
+%       a \textt{tabu} with \textt X columns.
+% \item \label{item:default target width} If the width of the whole tabular is not specified with ``\textt{tabu to}''
+%       it is considered to be \cs{linewidth}.
 %       \nameref{subsec:linegoal package option} makes the default width equal to \cs{linegoal}. Compilation must then be done
 %       with \hologo{pdfTeX} either in \textt{pdf} or \textt{dvi} mode, and package \xpackage{linegoal} is loaded.
-%       Remember that \cs{linegoal} uses \xpackage{zref-savepos} and \cs{pdfsavepos}:
+%       \cs{linegoal} requires \hologo{pdfTeX} for its \cs{pdfsavepos} primitive and the \xpackage{zref-savepos}:
 %       if the \textt{tabu} is not alone in its paragraph \ie if the target is not
 %       \cs{linewidth}, then two compilations (or more) are required to get the correct target. \\
-%       Default target for nested \textt{tabu} environments is always \cs{linewidth}, which is the column width inside \textt p,
-%       \textt m, \textt b and \textt X columns.
+%       Default target for nested \textt{tabu} environments is always \cs{linewidth}, which equals to the column width inside
+%       \textt p, \textt m, \textt b and \textt X columns.
 % \item As long as the \cs{halign} content is expanded more than once, protections against counters incrementation, whatsits (\emph{write})
 %       index entries, footnotes \etc. are set up: the mechanism of \xpackage{tabularx} is reimplemented and enhanced for \textt{tabu X} columns.
 %       \cs{tabuDisableCommands} can be used to neutralize the expansion of additional macros during the trials.
 % \end{itemize}
 %
 % \subsubsection(X columns with tabu spread){X columns with ``\textt{tabu spread}''}
+% \label{X columns with tabu spread}
 %
 % \textt{tabu X} columns can be used with ``\textt{tabu spread}'' to adjust the column widths of tabulars that contain
 % only small pieces of text. The question is: how to make a tabular the width of the line, with 6 columns; the columns 1, 2, 5 and 6
@@ -539,7 +702,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %  \bigskip
 %
 % But the text in each cell is very short: one single character, and you prefer the table to be tight,
-% but don't know the exact width of the whole:\pagebreak
+% but don't know the exact width of the whole:
 %
 % \begin{Verb*}
 % \begin{tabu} spread 0pt{|X[2]|X[2]|X|X|X[2]|X[2]|} \hline
@@ -575,7 +738,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \end{Verb*}
 %
 % {\footnotesize
-% \begin{tabu} spread 3cm{@{}X[9]>{\parskip=5pt}X[4]|X|}
+% \begin{tabu} spread 3cm{@{}X[9]X[4]|X|}
 % "Like the air we breathe, Sherlock Holmes is everywhere.
 % His pipe-smoking, deer stalkered image peers at us from ads in Yellow Pages,
 % to signs for neighbourhood crime-watch; from billboards to the classroom;
@@ -584,14 +747,40 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % to become an international best-seller and has been accepted as part
 % of British folklore. Holmes is alive to millions."
 % &
-% There the text was too long, and \textt{tabu spread} behaves as if you didn't give it a target.\par
+% There the text was too long, and \textt{tabu spread} behaves as if you didn't give it a target.\par\vskip\baselineskip
 % The result of this example is the same as if one had written \cs{begin}\M*{tabu}\textt{to}\cs{linewidth}.
 % & \cellcolor{GhostWhite}\centering\rotatebox{-90}{\kern-1.4ex\bfseries Sherlock Holmes}
 % \\ \tabucline{1-2}
-% \multicolumn{2}{|c|}{And a \cs{multicolumn} cell, just to see} & \omit \\ \tabucline{1-2}
+% \multicolumn{2}{|c|}{The ``official'' web site: \url{http://www.sherlockholmes.com/}} & \omit \\ \tabucline{-2}
 % \end{tabu}}
 %
-% In the preamble, \textt{@\M*{}} means that you remove the margin.
+% In the preamble, \textt{@\M*{}} means that the margin is removed.
+%
+% \subsubsection{Negativ width coefficients for \textt X columns}
+%
+% \begin{Verb}
+% \begin{tabu}{|[3pt ForestGreen]X[-1m]|X[c m]|[3pt ForestGreen]}
+%                                   \tabucline[3pt ForestGreen]-
+%   $\begin{tabu}({X[-1$]X[-1$c]})     % equivalent to spread 0pt
+%      \alpha & \beta \\
+%      \gamma & \delta + \epsilon + \zeta + \eta + \theta
+%   \end{tabu}$
+%   &
+%   This is a tabu with negativ width coefficients for \textt X columns
+%   \\ \tabucline[3pt ForestGreen]-
+% \end{tabu}
+% \end{Verb}
+%
+% \begin{tabu}{|[3pt ForestGreen]X[-1m]|X[c m]|[3pt ForestGreen]} \tabucline[3pt ForestGreen]-
+%   $\begin{tabu}({X[-1$]X[-1$c]})
+%      \alpha & \beta \\
+%      \gamma & \delta + \epsilon + \zeta + \eta + \theta
+%   \end{tabu}$
+%   &
+%   This is a tabu with negativ width coefficients for \textt X columns
+%   \\ \tabucline[3pt ForestGreen]-
+% \end{tabu}
+%
 %
 % \subsubsection{Multicolumn in \textt{tabu}}
 %
@@ -637,8 +826,11 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 % This section should contain some examples but I've no time presently...
 %
+% However, this document has plenty of nested \textt{tabu}{\smaller s}!
+%
 %
 % \subsection{Lines inside \textt{tabu}}
+% \label{Lines inside tabu}
 %
 % \subsubsection{First important remarks}
 %
@@ -651,24 +843,26 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %
 % \subsubsection(Vertical lines){Vertical lines: \textt\textbar\ has an optional parameter}
+% \label{Vertical lines}
 %
 % Inside \textt{tabu} environment, the vertical line marker \textt\textbar\  has an \emph{optional} argument
 % which is the width of the vertical rule. The default width remains \cs{arrayrulewidth} of course.
 % The optional argument for \textt\textbar\ can also contain the name of a color.
 % color \emph{names} are only possible, not a color specification by the mean of a color model.
-% The width of the line if specified, must come before the color name (sorry for that, but I was tired
-% to parse parameters... as for \textt X columns, commas are optional).
+% The width of the line if specified, must come before the color name and... as for \textt X columns
+% parameters, commas are optional.
+%
 % Example:
 %
 % {\tabcolsep=3pt
-% \begin{tabu}{@{}X[3mc]X[3m]X[6m]@{}} \toprule
+% \begin{tabu}{@{}X[-1mc]X[m]X[2ml]@{}} \toprule
 %     \begin{tabu}{||[5pt]|c|c||[5pt]|}
 %        Hello & World
 %     \end{tabu}
 % &
 % The \textt{tabu} you see on left was made with the code displayed on the right.
 % &
-% \verbatim{
+% \verbatim{^^A
 % \begin{tabu}{||[5pt]|c|c||[5pt]|}^^@
 %     Hello & World^^@
 % \end{tabu}}
@@ -679,12 +873,12 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % &
 % The \textt{tabu} you see on left was made with the code displayed on the right.
 % &
-% \verbatim{
+% \verbatim{^^A
 % \begin{tabu}{||[5pt,red]|c|c||[5pt blue]|}^^@
 %     Hello & World^^@
 % \end{tabu}}
 % \\ \bottomrule
-% \multicolumn{3}{r}{\scriptsize\lk The \cs{verbatim} command available inside \textt{tabu} with \textt X columns was used: guess in which cells...?}
+% \multicolumn{3}{r}{\scriptsize\lk This example was printed inside a \textt{tabu} whose preamble is: \textt{X[$-$1m]X[m]X[2m]}.}
 % \end{tabu}}
 %
 % Note that it is always a good idea to protect the optional argument with braces: \M*[\M*{...}].
@@ -718,7 +912,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 % {\parskip=0pt\topsep=0pt
 % \begin{center}\def\margintext#1{\noalign{\vtop to0pt{\marginnote{\ttfamily\small #1}[-1.8ex]\vss}}}^^A
-% \begin{tabu}{|[1.5pt]|>{\ttfamily}X@{\hskip\tabcolsep}X[1.4]||[1.5pt]} \tabucline[\heavyrulewidth]- \savetabu{tabucline}
+% \begin{tabu}{|[1.5pt]|>{\ttfamily}X[-1]X||[1.5pt]} \tabucline[\heavyrulewidth]- \savetabu{tabucline}
 %  \cs{tabucline}\M*[1pt on 1.5pt off 2pt]\M*{1-4} & draws a horizontal dashed line of width \textt{1pt}. Dashes are
 %                                                    \textt{1.5pt} long and gap width is \textt{2pt}. The line is drawn
 %                                                    between columns 1 and 4. Here there are only 2 columns and the line
@@ -729,7 +923,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %                                                    column and the last one.\\ \tabucline{2-} \margintext{default}
 %  \cs{tabucline}\M*[on 2pt red]\M*{-5}            &  draws a horizontal dashed line between columns 1 and 5
 %                                                     of width \cs{arrayrulewidth}. Dashed are
-%                                                    \textt{2pt} long and gaps width is \textt{4pt} (the default).
+%                                                    \textt{2pt} long and gap width is \textt{4pt} (the default).
 %                                                    \\ \tabucline[on 2pt red]{-5} \margintext{[on 2pt red]}
 % \end{tabu}
 % \end{center}}
@@ -768,19 +962,19 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \multicolumn3c{In each table, \cs{extrarowheight} is equal to \textt{8 pt}.} \\
 % \end{tabu}}
 %
-% \cs{tabuclines} tries to put the line in the middle, so that the text is centered in its cell. \enlargethispage\baselineskip
+% \cs{tabuclines} tries to put the line in the middle, so that the text is centered in its cell. 
 % \cs{tabuclines}\stform* tries to take care of vertical lines.
 % Well this is not perfect: it works pretty well with simple vertical lines, but not really with double
-% lines, triple lines with colors etc... But it can help in simple cases...
+% lines, triple lines with colours etc... But it can help in simple cases...
 %
 % \begin{declcs}{tabulinestyle}\M{style=spec., style=spec., style=spec. ...}
 % \end{declcs}
 %
 % This command defines a line style to be used in the first optional argument of \cs{tabucline}:
 %
-% \begin{tabu}{@{}X[1.6,c]@{}X[c]@{}} \tabucline[\heavyrulewidth]- \tabucline[\hbox{$\scriptstyle\star$}]- \toprule
+% \begin{tabu}{@{}X[-2,c]@{}X[c]@{}} \tabucline[\heavyrulewidth]- \tabucline[\hbox{$\scriptstyle\star$}]- \toprule
 % \rowfont[c]{\bfseries} Define the line style & Use the line style \\ \midrule
-% \cs{tabulinestyle}\M*{myline=0.4pt on 1.5pt off 1pt} & \cs{tabucline}\M*[myline]\M*{-} \\ \tabucline[\heavyrulewidth on 1pt off 2pt]-
+% \cs{tabulinestyle}\M*{myline=0.4pt on 1.5pt off 1pt  red} & \cs{tabucline}\M*[myline]\M*{-} \\ \tabucline[\heavyrulewidth on 1pt off 2pt red]-
 % \cs{tabulinestyle}\M*{myleader=\cs{hbox}\M*{\$\cs{scriptstyle}\cs{star}\$}} & \cs{tabucline}\M*[myleader]\M*{1-3} \\
 % \multicolumn{2}{c}{This way it is easy to change dashed lines into solid ones} \\ \bottomrule \tabucline[\hbox{$\scriptstyle\star$}]- \tabucline[\heavyrulewidth]-
 % \end{tabu}
@@ -805,7 +999,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \end{tabu}
 % \end{tabu}
 %
-% \enlargethispage{2\baselineskip}
+% ^^A\enlargethispage{2\baselineskip}
 % \small
 % \hfil\Shapepar{\nutshape}{Now we stop it because things are becoming too ugly and go to have a look at \textt{tabu} in mathematical mode...}\hfil\null
 %
@@ -813,6 +1007,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %
 % \subsection{\textt{tabu} in math mode}
+% \label{sec.math mode}
 %
 % {
 % \extrarowheight=3pt
@@ -880,6 +1075,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %
 % \subsection{Verbatim inside \textt{tabu} with \textt X columns}
+% \label{Verbatim inside tabu}
 %
 % The process of computing \textt X columns widths implies to make ``trials'': this means that
 % the tabular is first printed in internal mode, inside a box which is measured until the target
@@ -957,6 +1153,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \def\usermacro#1{\numprint[\officialeuro]{\zap@space #1 \@empty}}
 % \makeatother
 %
+%
 % \begin{tabu}{XX}
 % \multicolumn{2}{l}{\verbatim{\begin{tabu}{|[GreenYellow]*2{>{\tabudecimal\usermacro}X[r]|[GreenYellow]}}}} \\
 % \verbatim{
@@ -1031,6 +1228,13 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 % {\centering
 % \extrarowheight=8pt
+% \AtBeginShipoutNext{\AtBeginShipoutUpperLeft{\tikz[remember picture,overlay]
+%           \node at (tabularx overfull) [xshift=-3cm,yshift=-1cm,rotate=45,font=\ttfamily\smaller] 
+%              {\begin{tabu}{c}
+%                 with overfull hboxes\\
+%                 (15.8pt and 16.1pt two wide)\\
+%                 for \xpackage{tabularx}
+%               \end{tabu}};}}
 % \begin{tabu}to .6\linewidth{X[m]} \tabucline-
 % \extrarowheight=0pt
 % \begin{tabu}({X})
@@ -1040,7 +1244,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 % \extrarowheight=0pt
 % \begin{tabularx}{\linewidth}[t]({X})
-%  This is \textt{tabularx} with \xpackage{delarray} shortcut for parenthesis around
+%  \tikzlabel{tabularx overfull} This is \textt{tabularx} with \xpackage{delarray} shortcut for parenthesis around
 % \end{tabularx}
 % \\ \tabucline[1pt on2pt blue]-
 %
@@ -1056,13 +1260,11 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \end{tabularx}
 % \\ \tabucline-
 %
-% \end{tabu}
-% \par}
+% \end{tabu}\par}
 %
-% With \textt{overfull hboxes (15.8pt and 16.1pt too wide)} for \textt{tabularx}.
 %
 %
-% \section(save the tabu preamble){Save the \textt{tabu} preamble and \textt X columns widths: \cs{savetabu}, \cs{usetabu}}
+% \section(Saving and restoring tabu){Saving and restoring a \textt{tabu}: \cs{savetabu}, \cs{usetabu} and \cs{preamble}}
 %
 % \begin{declcs}{savetabu}\M{user-name}
 % \end{declcs}
@@ -1077,65 +1279,97 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % If the \meta{user-name} has been used before, an info is displayed in the \xext{log} file and the
 % previous settings are overwritten.
 %
+% With the \hyperref[debugshow]{\textt{debugshow} package option} (or \csref{tracingtabu}) the informations
+% saved by \cs{savetabu} are reported in the \xext{log} file.
+%
 %
 % \begin{declcs}{usetabu}\M{user-name}
 % \end{declcs}
 %
-% \cs{usetabu} is the complement of \cs{savetabu}: it can be used in the \textt{tabu}
+% \cs{usetabu} is the complement of \cs{savetabu}: it can be put alone in the \textt{tabu}
 % preamble instead of the usual columns specifications
 % to restore any previous settings saved with \cs{savetabu}.
 % The \meta{user-name} must exist otherwise, you get an error.
 %
-% \cs{usetabu} locally restores:
+% \cs{usetabu} does not work with \hyperref[sec.longtabu]{\textt{longtabu}}.
+% 
+% \needspace{2\baselineskip}
+%
+% \cs{usetabu} locally restores:\nobreak
 % \begin{itemize}
-% \item the preamble,
+% \item the preamble\footnote{The complete \cs{halign}-preamble is restored.}.
+% \item the vertical position \M*[c],\, \M*[b]\, or\, \M*[t], unless another position is specified.
 % \item the target width of the \textt{tabu} in points: the saved target width does not contain
-%       any control sequence: it is fixed and stored in points,
-% \item the width of \textt{tabu X} columns: those widths are not calculated any more, and \textt{X}
-%       columns are directly transformed into \textt p, \textt m or \textt b columns.
-% \item \cs{tabcolsep} (or \cs{arraycolsep} in math mode)
+%       any control sequence: it is fixed and stored in points.
+% \item the width of \textt{tabu X} columns: those widths are not calculated any more, even in the case
+%       of negativ coefficients and \textt{X} columns are directly transformed into
+%       \textt p, \textt m or \textt b columns of the same widths as the ones that where calculated
+%       at the time of \cs{savetabu}
+% \item \cs{tabcolsep} (or \cs{arraycolsep} in math mode) and \cs{arraystretch}
 % \item \cs{arrayrulewidth}, \cs{doublerulesep}, \cs{extrarowheight} and \cs{extratabsurround}
+% \item \cs{minrowclearance}, \cs{arrayrulecolor} and \cs{doublerulesepcolor} (package \xpackage{colortbl})
 % \end{itemize}
 %
 % Example:
 %
-% \begin{Verb*}
-%  \extrarowheight=5pt\tabcolsep=12pt
+%  \begin{Verb*}
+%  \extrarowheight=5pt\tabcolsep=12pt\arrayrulecolor{ForestGreen}
 %  \begin{tabu}to .7\linewidth{|XXX|X[c]|} ($db(\savetabu)){mytabu}   \tabucline*[on1pt]-
 %   This & is & tabu & package                                             \\ \tabucline*[on1pt]-
 %  \end{tabu}
-% \end{Verb*}
+%  \end{Verb*}
 %
 %  \begin{center}
-%  \tabulinestyle{myline=on1pt}\extrarowheight=5pt\tabcolsep=12pt
+%  \tabulinestyle{myline=on1pt}\extrarowheight=5pt\tabcolsep=12pt\arrayrulecolor{ForestGreen}
 %  \begin{tabu}to .7\linewidth{|XXX|X[c]|} \savetabu{mytabu} \tabucline*[myline]-
-%   This & is & tabu & package         \\ \tabucline*[myline]-
+%   This & is & tabu & package             \\ \tabucline*[myline]-
 %  \end{tabu}
 %  \end{center}
 %
-% \begin{Verb*}
+%
+%  \begin{Verb*}
 %  \begin{tabu}{($db(\usetabu)){mytabu}}                                          \tabucline*[on1pt]-
 %  \multicolumn3{|c}{This is tabu} & package                         \\ \tabucline*[on1pt]-
 %  \tabuphantomline
 %  \end{tabu}
-% \end{Verb*}
+%  \end{Verb*}
 %
-% \begin{center}
+%  \begin{center}
 %  \begin{tabu}{\usetabu{mytabu}}            \tabucline*[myline]-
 %  \multicolumn3{|c|}{This is tabu} & package    \\ \tabucline*[myline]-
 %  \tabuphantomline
 %  \end{tabu}
-% \end{center}
+%  \end{center}
 %
 % If one day you use \textt{tabu}, you will have the idea to restore a \textt{tabu} while modifying its target,
 % or adding new columns... \cs{savetabu} and \cs{usetabu} have not been thought for this purpose, and you may
 % have unexpected results. \cs{usetabu} is a help to get several tabulars of exactly the same shape, same target,
-% same preamble.
+% same preamble. The only parameter that can be changed is the optional vertical position parameter
+% for the whole tabular.
 %
+% \begin{declcs}{preamble}\M{user-name}
+% \end{declcs}
+%
+% \cs{preamble} can also be used after \csref{savetabu}. This is a variant of \cs{usetabu} that locally restores:
+% \begin{itemize}
+% \item the \textt{tabu} (or \textt{longtabu}) preamble.
+% \item the vertical position \M*[c],\, \M*[b]\, or\, \M*[t]  (or \M*[c],\, \M*[l]\, or\, \M*[r] for \textt{longtabu}),
+%       unless another position is specified.
+% \item the \textt{tabu} / \textt{longtabu} target width, unless another target is specified.
+% \end{itemize}
+% Any other tabular parameters are not restored.
+% 
+% Put \cs{preamble}\M{user-name} alone inside the \textt{tabu} (or \textt{longtabu}) preamble in place of the usual
+% columns specifications.
 %
+% \cs{preamble} works exactly as if you defined a \hyperref[Custom environments]{custom environment} for \textt{tabu}.
 %
+% \cs{preamble} works with \hyperref[sec.longtabu]{\textt{longtabu}}.
 %
-% \section(row font and alignment){Change the font and the alignment in one row: \cs{rowfont}}
+% 
+%
+%
+% \section(row font and alignment){Modifying the font and the alignment in one row: \cs{rowfont}}
 %
 % \begin{declcs}{rowfont}\M[alignment]\M*{font specification}
 % \end{declcs}
@@ -1158,20 +1392,20 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \textt L\, \textt R\, \textt C\, and\, \textt J\, are synonymous with the lowercase equivalent.
 %
 % \begin{Verb*}
-%  \begin{tabu}{|X|X|}              \tabucline-
+%  \begin{tabu}{|X|X[-1]|}              \tabucline-
 %     ($db(\rowfont))[c]\bfseries
 %      This & Is                        \\ \tabucline[on 2pt,blue]-
-%     \textt{tabu} & package      \\ \tabucline-
+%     \textt{tabu} & package for \textt{tabu} and \textt{longtabu}      \\ \tabucline-
 %  \end{tabu}
 % \end{Verb*}
 %
-% \begin{tabu}{|X|X|}\tabucline-
+% \begin{tabu}{|X|X[-1]|}\tabucline-
 % \rowfont[c]\bfseries This & Is \\ \tabucline[on 2pt,blue]-
-% \textt{tabu} & package \\ \tabucline-
+% \textt{tabu} & package for \textt{tabu} and \textt{longtabu} \\ \tabucline-
 % \end{tabu}
 %
 %
-% \section(Differences: tabu, tabular, tabularx){Differences between \textt{tabu}, \textt{tabular} and \textt{tabularx}}
+% \section(Differences: tabu, tabular, tabularx, longtable){Differences between \textt{tabu}, \textt{tabular}\, \textt{tabularx} and \textt{longtable}}
 %
 % \subsection{Paragraph indentation}
 %
@@ -1179,7 +1413,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % no matter if it has been loaded or not with the \textt{linegoal} option.
 % Example with \LaTeX{} default: \cs{parindent} $=20$pt.
 %
-% {\parindent=20pt \makeatletter\let\tabudefaulttarget\linewidth\makeatother
+% {\parindent=20pt \let\tabudefaulttarget \linewidth
 %
 % \begin{tabu}{|[GreenYellow]X|[GreenYellow]} \tabucline[GreenYellow]-
 % This is \textt{tabu} with its default target in an indented paragraph. \\ \tabucline[GreenYellow]-
@@ -1200,6 +1434,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %
 % \subsection{Custom environments}
+% \label{Custom environments}
 %
 % Unlike \textt{tabularx}, it is possible to define your own environment using \textt{tabu}:
 %
@@ -1263,10 +1498,48 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % In math mode however, tokens are in the reverse order in the \textt{tabu} environment
 % like they are in the \textt{array} environment.
 %
-% \subsection(Improved rewrite process){Improved process for rewritting columns}
+% \subsection(Improved rewrite process){Improved process for rewritting columns \textmd{\emph{(for keen readers)}}}
+%
+% Any tabulars that do not split accross pages are made with the following process:
+%
+% \begin{tikzpicture}[
+%    start chain=going below, every join/.style={->,thin,black,solid},node distance=.5cm and 1cm,
+%    every node/.style={black,on chain}]
+% \node (initialisation) at (0,0) {\begin{tabu}{c} initialisation \\ \cs{hbox}\end{tabu}}
+%  node (@array) [join] {\cs{@array}}
+%  {[start branch]
+%        node (@arraydesc) [join] {%
+%          \begin{tabu}\{{l}.
+%             \begin{tabu}[c].{l}\}
+%             \cs{begingroup} \\
+%             \qquad \cs{@mkpream}\M*{preamble} \\
+%             \cs{endgroup} \\
+%             \end{tabu} ``\textt{@mkpream}'' group
+%             \\[4ex]
+%             \cs{halign}\M*{\cs{@preamble} \textellipsis\ tabular content }
+%          \end{tabu}}
+%  }
+%  node (end) [join] {end of \cs{hbox}};
+% \end{tikzpicture}
+%
+% For more details, see the \nameref{Flow chart of expansion}.
+%
+% \cs{@mkpream} works in two times inside a (semi-simple) group:
+%
+% \begin{description}[font=\mdseries\itshape,topsep=0pt,itemsep=0pt]
+% \item [First the rewriting process:] \ \\
+%    Each special column in the tabular preamble is transformed into
+%    one the columns defined by \xfile{array.sty}.
+% \item [Second the building of the \textup{\cs{halign}} preamble:] \ \\
+%    The ``rewritten preamble'' is parsed and transformed in a preamble for the \TeX{} primitive
+%    \cs{halign}. The result is stored into the \cs{@preamble} macro.
+% \end{description}
+%
+% Any special columns of \textt{tabu} are defined only inside the ``\textt{@mkpream}'' group.
 %
 % In the following example, you get an error with \textt{tabular} and no error with \textt{tabu}.
-% With \textt{tabular}, and \xpackage{siunitx} \textt S column, the rewritting process is as follow:
+% With \textt{tabular}, and \xpackage{siunitx} \textt S column, the {\descfont\mdseries\itshape rewritting process}
+% is as follow:\nobreak
 %
 % \begin{SaveVerbatim}{siunitx}
 % \documentclass{minimal}
@@ -1304,16 +1577,20 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \item Rewrite \stform*
 % \item Rewrite \textt\textbar\
 % \item Rewrite \textt S
-% \item Rewrite \textt n \smex not found because \textt S rewritten before, according to \xpackage{siunitx} definition.
+% \item Rewrite \textt n \smex not found because \textt S was rewritten before, according to \xpackage{siunitx} definition.
 % \end{enumerate}
 % \end{tabu}
 %
 % The process of rewritting columns is usually longer inside \textt{tabu} than inside \textt{tabular},
 % but conversely \textt{tabu} with \textt X columns is optimised compared to \textt{tabularx},
-% because the preamble is built only once, not rebuilt before each trial as \textt{tabularx} does...
+% because the preamble is built only once, and not rebuilt before each trial as \textt{tabularx} does.
+% Thus \textt{tabu} is much quicker than \textt{tabularx}.
 %
 % The process of rewritting is very sensitiv to the order in which columns are actually rewritten.
-% Therefore, if it possible to define a new column type using the \textt X token for use with \textt{tabu}:\nobreak
+% This becomes critical when columns are defined with an optional argument like \xpackage{tabu} \textt X
+% and \textttbf\textbar\ columns or \xpackage{siunitx} \textt S column.
+%
+% If it possible to define a new column types using the \textt X token for use with \textt{tabu}:\nobreak
 % \begin{Verb*}
 % \newcolumntype{C}{X[c]}
 % \end{Verb*}
@@ -1323,8 +1600,8 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \newcolumntype{Q}{>{\color{green}}C}
 % \end{Verb*}
 %
-% In fact, a problem may arise in nested \textt{tabu}{\small s} if such a \textt Q column type
-% is defined before the \textt C column type...
+% In fact, a problem may arise in nested \textt{tabu}{\small s} if such a \textt Q column
+% is defined before the \textt C column...
 %
 % Well, just avoid to nest new column type definitions !
 %
@@ -1333,13 +1610,20 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \section{The package options}
 %
 % \subsection(The debugshow option){The \textt{debugshow} package option}
+% \label{debugshow}
 %
-% \begin{declcs}{tracingtabu}
+% \begin{declcs}{tracingtabu} \\
+%            \cs{tracingtabu}\,=\,2
 % \end{declcs}
 %
-% With the package option \textt{debugshow}, \xpackage{tabu} will report the widths it computes
-% at each attempt to read the target, when \textt X columns are used.
-% The control sequence \cs{tracingtabu} has the same effect as the \textt{debugshow} option.
+% The control sequence \cs{tracingtabu} has the same effect as the \textt{debugshow} option:
+% \begin{itemize}
+% \item \xpackage{tabu} will report the widths it computes at each attempt to read the target,
+%        when \textt X columns are used.
+% \item Saved informations on the \textt{tabu} are reported in the \xext{log} file when \cs{savetabu}
+%       is used.
+% \end{itemize}
+%
 %
 % Typical information in the \xext{log} file:
 %
@@ -1349,7 +1633,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % (tabu)     &Try &tabu X                                        &tabu Width  &Target      &Coefs &Update \\
 % (tabu)     &1)  &386.67296pt                                   &797.34592pt &386.67296pt &2.0pt &-205.33649pt \\
 % (tabu)     &2)  &181.33647pt                                   &386.67294pt &386.67296pt &2.0pt &0.00002pt \\
-% (tabu)     &2)  & \multicolumn{5}{l}{\ \ Target Reached (hfuzz=0.1pt) **************** }\\
+% (tabu)     &2)  & \multicolumn5l{\ \ Target reached (hfuzz=0.1pt) **************** }\\
 % \end{tabu}}
 %
 % What does it mean? \def\pt#1{$#1$\textt{pt}}
@@ -1362,6 +1646,8 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %       The final width of each \textt X column is the product of \textt{tabu X} by its width coefficient.
 % \end{enumerate}
 %
+% \cs{tracingtabu}=2 gives even more information about the measuring of natural widths of columns.
+%
 % \subsection(The linegoal option){The \textt{linegoal} package option}
 % \label{subsec:linegoal package option}
 %
@@ -1376,6 +1662,8 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % you can say (in a group for example):
 % \verb+\let\tabudefaulttarget=\linewidth+
 %
+% In any case, specifying the target overwrites the default: \cs{begin}\M*{tabu} to\cs{linewidth}
+%
 % \subsection(The delarray option){The \textt{delarray} package option}
 %
 % \textt{delarray} option has the single effect to load \xfile{delarray.sty} for delimiters shortcuts
@@ -1406,41 +1694,52 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % As a consequence: \cs{rowfont} and \cs{tabucline} will not be available, and vertical lines \texttt\textbar\
 % will not have an optional argument for their widths and color. However, \textt{tabu X} columns will work normally.
 %
+% ^^A\medskip
+% ^^A As the author of \thispackage, I often use the \textt{light} option when implementing \textt{tabu}, for the
+% ^^A\xext{log} file is lighter too...
+%
 %
-% \section(Corrections){Corrections of some bugs (available only inside \textt{tabu})}
+% \section(Corrections){Corrections of some bugs \textmd{\emph{(available only inside \textt{\upshape tabu})}}}
 %
-% \subsection(delarray compatibility){Correction for colortbl and arydshln: compatibility with delarray}
+% \subsection(delarray compatibility){Correction for \xpackage{colortbl} and \xpackage{arydshln}: compatibility with \xpackage{delarray}}
 %
 % Both \xpackage{colortbl} and \xpackage{arydshln} forget the control sequence \cs{@arrayright} in their implementation,
-% quite strangely because both of them take care of \cs{@arrayleft}.
+% quite strangely because both of them take care of \cs{@arrayleft}. As a result, \xpackage{delarray} shortcuts for
+% delimiters around a tabular does not work if \xpackage{colortbl} and/or \xpackage{arydshln} are loaded.
 %
-% Those control sequences are used by the \xpackage{delarray} package to put parenthesis or bracket around the array.
+% Those control sequences are used by the \xpackage{delarray} package to put variable size delimiters around the array:
 %
+% {\centering\tabcolsep=12pt
+% \begin{tabu}{X[-1m]X[-1mc]X[-1m]}
+% \verbatim{\begin{tabu}\{{X}.^^@ ...^^@ \end{tabu}} &
+%     is like: &
+%           \verbatim{\left\{ \begin{tabu}{X}^^@ ...^^@ \end{tabu} \right.}
+% \end{tabu}\par}
 %
-% \subsection(arydshln @ columns){Correction for arydshln: \texttbf @ columns}
+%
+% \subsection(arydshln @ columns){Correction for \xpackage{arydshln}: \texttbf @ columns}
 %
 % A bug in \cs{adl@xarraydashrule}: \textt{!-arg} columns (class 1) and \textt{@-arg} columns (class 5) should be treated
 % the same as far as rules are concerned.
 %
-% With this correction, the \textbf{known problem number 1} in \xpackage{arydshln} documentation is solved.
-%
-%
+% With this correction, the ``known problem number 1'' in \xpackage{arydshln} documentation is solved.
 %
-% \vskip2cm
 %
+% \section{To do for even better \textt{tabus}}
 %
+% \nprounddigits{0}
+% \begin{itemize}[leftmargin=*,label=\ding{223}]
+% \item Make double \cs{tabucline} with compatibility with \xpackage{colortbl} \cs{doublerulesepcolor}
+% \item Multiple \cs{tabucline} between different columns: extended specs: \\
+%        \cs{tabucline}\M*[line spec]\M*{start-stop,start-stop}\M*[line spec]\M*{start-stop} ...
+% \item Presently, \textt{longtabu} with \textt X columns works only if \cs{LTchunksize} is greater than the number of rows.
+%       I compiled a \textt{longtabu} of 56 pages on my PC with \cs{LTchunksize} $ = $ \numprint{2000} without problem.
+%       Presently \cs{LTchunksize} is set to \numprint{10000} during trials when \textt{longtabu} contains \textt{X columns}.
+% \item Make \cs{tabucline} work with page breaks (one line on the top of the page, one line on the bottom of the previous).
+% \item An environment ``\textt{calstabu}'' based on the \Xpackage{cals} package but with the syntax of \textt{tabular} if possible...
+% \end{itemize}
 %
-% \begin{SaveVerbatim}[commandchars=$(),gobble=1]{myVerb}
-%  ($db(\definecolorseries)){serie}{rgb}{last}{Goldenrod}{DarkSeaGreen}
-%  ($db(\resetcolorseries))[3]{serie}
-%  \begin{($dr$underline(parse lines))}{($dg(\color{serie!!+}``#1''\par))}
-%     This is a nice little package
-%     and I really don't know
-%     What to do with it !
-%     May be tomorrow...
-%  \end{($dr$underline(parse lines))}
-% \end{SaveVerbatim}
-%
+% \raggedbottom
 %
 %
 % \StopEventually{
@@ -1456,8 +1755,10 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \begin{macrocode}
 %<*package>
 \NeedsTeXFormat{LaTeX2e}[2005/12/01]
-\ProvidesPackage{tabu}[2010/11/22 v1.4 - flexible LaTeX tabulars (FC)]
+\ProvidesPackage{tabu}[2010/12/07 v1.5 - flexible LaTeX tabulars (FC)]
 \RequirePackage{array}[2008/09/09]
+\RequirePackage{varwidth}[2009/03/30]
+\let\DEBUG\@gobble%\message
 %    \end{macrocode}
 %
 %    Then minimal catcode acertaining for loading \thispackage in good conditions:
@@ -1483,42 +1784,52 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \cs{tracingtabu} is the same as option \textt{debugshow}.
 %
 %    \begin{macrocode}
-\let\tabu@message\@gobble
-\def\tracingtabu{\let\tabu@message\message}
-\let\tabudefaulttarget\linewidth
-\DeclareOption{debugshow}{\tracingtabu}
+\let\tabu@message         \@gobble
+\let\tabu@message@save    \@gobble
+\let\tabu@debug           \@gobble
+\def\tracingtabu{%
+   \let\tabu@message \message
+   \let\tabu@message@save \tabu@tracing@save
+   \@ifnextchar={\tabu@tracing}{}}
+\def\tabu@tracing{\begingroup\afterassignment\tabu@tr@cing\count@}
+\def\tabu@tr@cing{\expandafter\endgroup\ifnum\count@>\@ne
+   \let\tabu@debug\message\else\let\tabu@debug\@gobble\fi}
+\DeclareOption{debugshow}{\AtEndOfPackage\tracingtabu}
 %    \end{macrocode}
 %    \end{macro}
 %
 %    \begin{macro}{linegoal (package option)}
+%
 %    \begin{macrocode}
+\let\tabudefaulttarget    \linewidth
 \DeclareOption{linegoal}{%
-   \AtEndOfPackage{\RequirePackage{linegoal}[2010/10/31]}%
-   \def\tabudefaulttarget{\linegoal}% \linegoal is \linewidth if not pdfTeX
-}% linegoal option
+   \AtEndOfPackage{%
+      \RequirePackage{linegoal}[2010/12/07]%
+      \let\tabudefaulttarget \linegoal% \linegoal is \linewidth if not pdfTeX
+}}
 %    \end{macrocode}
 %    \end{macro}
 %
 %    \begin{macro}{delarray (package option)}
+%
 %    \begin{macrocode}
 \DeclareOption{delarray}{%
    \AtEndOfPackage{\RequirePackage{delarray}}%
-}% delarray option
+}
 %    \end{macrocode}
 %    \end{macro}
 %
 %    \begin{macro}{light (package option)}
+%
 %    \begin{macrocode}
 \DeclareOption{light}{%
    \AtEndOfPackage{%
-      \let\tabu@prepnext@tok \prepnext@tok
-      \let\tabu@save@decl \save@decl
-      \let\tabu@rowfont \tabu@norowfont
-      \let\tabucline \tabu@nocline
-      \let\tabu@firstcline \relax
-      \let\tabu@lines \relax
+   \let\tabu@prepnext@tok \prepnext@tok    \let\tabu@save@decl \save@decl
+   \let\tabu@rowfont      \tabu@norowfont  \let\tabucline      \tabu@nocline
+   \let\tabu@firstcline   \relax           \let\tabu@lines     \relax
+   \let\tabu@setup@everycr\relax
    }
-}% light option
+}
 \def\tabu@norowfont{\PackageError{tabu}
    {\string\rowfont\space is not available with option `light'}\@ehd}
 \def\tabu@nocline{\PackageError{tabu}
@@ -1541,10 +1852,13 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \begin{macrocode}
 \AtBeginDocument{%
    \@ifundefined{NC@rewrite@X}{\newcolumntype{X}{}}{}% new column X if not exists
-   \expandafter\in@\expandafter\@arrayright\expandafter{\endarray}%
-   \ifin@ \let\tabu@endarray\endarray
-   \else \tabu@fix@arrayright \fi % <fix for colortbl & arydshln (delarray)>
+   \expandafter\in@ \expandafter\@arrayright\expandafter{\endarray}%
+   \ifin@ \let\tabu@endarray \endarray
+   \else  \tabu@fix@arrayright \fi % <fix for colortbl & arydshln (delarray)>
    \@ifpackageloaded{colortbl} \tabu@colortbltrue \tabu@colortblfalse
+   \@ifpackageloaded{arydshln}{}
+      {\let\tabu@adl@fix \relax \let\tabu@adl@endTRIAL \@empty}%
+   \@ifpackageloaded{longtable}{}{\let\longtabu \tabu@nolongtabu}%
 }
 %    \end{macrocode}
 %
@@ -1563,11 +1877,12 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    Used only when \textt{tabu X} columns are used with ``\textt{tabu spread}''.
 %
 %    \begin{macrocode}
-\newcount\tabu@cnt
-\newcount\tabu@nbcols
-\newcount\tabu@X@cols
-\newcount\tabu@start
-\newcount\tabu@stop
+\newcount \tabu@cnt
+\newcount \tabu@nbcols
+\newcount \tabu@X@cols
+\newcount \tabu@start
+\newcount \tabu@stop
+\newcount \tabu@nested
 %    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
@@ -1584,9 +1899,9 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %     Used only when \textt{tabu X} columns are used with ``\textt{tabu spread}''.
 %
 %    \begin{macrocode}
-\newdimen\tabu@target
-\newdimen\tabu@spreadtarget
-\newdimen\tabu@naturalX
+\newdimen \tabu@target
+\newdimen \tabu@spreadtarget
+\newdimen \tabu@naturalX
 %    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
@@ -1601,12 +1916,19 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    Stores the sum of all width coefficients for \textt X columns.
 %
+%    \begin{macro}{\tabucolX@error}
+%
+%     In case of \textt X columns too narrow.
+%
 %    \begin{macrocode}
-\newdimen\tabucolX
-\newdimen\tabu@X@sum
+\newdimen \tabucolX
+\newdimen \tabu@X@sum
+\newdimen \tabucolX@error \tabucolX@error=1em
 %    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
+%    \end{macro}
+%
 %
 %    \begin{macro}{\iftabu@measuring}
 %
@@ -1614,31 +1936,32 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    It is also temporarily set to true when the first \textt X column is encountered in the \textt{tabu} preamble,
 %    at the time \cs{@mkpream} scans it to built the \cs{halign} preamble. The first \textt X column found
-%    actually triggers some special setup to be expanded before \cs{halign} (see the flow chart...)
+%    actually triggers some special setup to be expanded before \cs{halign} (see the \hyperref[Flow chart of expansion]{flow chart...})
 %
 %    \begin{macro}{\iftabu@spread}
 %
 %    A switch whether ``\textt{tabu spread}'' is used or not.
 %
-%    \begin{macro}{\iftabu@nested}
-%
-%    A swith set at the entry in \textt{tabu} environment: true if \textt{tabu} is nested inside another \textt{tabu}.
-%
 %    \begin{macro}{\iftabu@firstcline}
 %
 %    A switch to adapt \cs{tabucline} automatically if it comes first in the \textt{tabu} (similar to \cs{firsthline}).
 %
+%    \begin{macro}{\iftabu@negcoef}
+%
+%    A switch set to true in case of negativ coef (natural width if less than \textt{X[coef]}).
+%
 %    \begin{macrocode}
-\newif\iftabu@measuring
-\newif\iftabu@spread
-\newif\iftabu@nested
-\newif\iftabu@firstcline
+\newif \iftabu@measuring
+\newif \iftabu@spread
+\newif \iftabu@firstcline
+\newif \iftabu@negcoef
 %    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
 %    \end{macro}
 %    \end{macro}
 %
+%
 %    \begin{macro}{\tabu@box}
 %
 %    Stores the whole \textt{tabu} when an attempt to adjust \textt X columns is performed.
@@ -1646,8 +1969,8 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    It is also used by \cs{tabucline} to save the \cs{@arstrutbox} when inserting a horizontal line.
 %
 %    \begin{macrocode}
-\newsavebox\tabu@box
-\chardef\tabu@arstrutbox=\@arstrutbox
+\newsavebox \tabu@box
+\chardef \tabu@arstrutbox=\@arstrutbox
 \let\tabu@vcenter \vcenter
 %    \end{macrocode}
 %    \end{macro}
@@ -1656,8 +1979,26 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    A macro which is needed when scanning tokens with \cs{futurelet}.
 %
+%    \begin{macro}{\tabu@gobbleopt}
+%
+%    A macro that gobbles an optional argument.
+%
 %    \begin{macrocode}
 \def\tabu@gobblespace#1 {#1}
+\def\tabu@gobbleopt#1{\@ifnextchar [{\tabu@gobble@pt{#1}}{#1}}%]
+\def\tabu@gobble@pt#1[#2]{#1}
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+%    \begin{macro}{\tabu@save@decl}
+%
+%    No inversion on tokens in the \text{tabu} preamble, when not in math mode.
+%
+%    \begin{macrocode}
+\def\tabu@save@decl{%
+   \toks\count@ = \expandafter{\the\toks\expandafter\count@\@nextchar}%
+}% \tabu@save@decl
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -1672,37 +2013,55 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \begin{macrocode}
 \newcommand\tabu@NC@rewrite@X[1][]{\tabu@rewrite@X{#1}%
                                  \let\@halignto \relax
-                  \expandafter \NC@find \tabucolX@spec}
+                  \expandafter \NC@find \tabucolX@rw}
 %    \end{macrocode}
 %    \end{macro}
 %
 %  The next part of the definition (\cs{tabu@rewrite@X}) can be found page \pageref{tabu X column definition}.
 %
+%    \begin{macro}{\tabu@newcolumntype}
+%
+%    A helper macro to create local new column types for \textt{tabu}.
+%
+%    \begin{macrocode}
+\def\tabu@newcolumntype #1{%
+   \expandafter\def\csname NC@find@\string#1\endcsname##1#1{\NC@{##1}}%
+   \expandafter\def\csname NC@rewrite@\string#1\endcsname%
+}% \tabu@newcolumntype
+%    \end{macrocode}
+%    \end{macro}
+%
+%
 %    \begin{macro}{\usetabu (new column type)}
 %
-%    \cs{usetabu} is defined as a new column type. \cs{NC@rewrite@\string\usetabu} is expanded
-%    where \cs{@mkpream} does its job.
+%    \cs{usetabu} is defined as a \textt{tabu} new column type: loaded only inside the \cs{@mkpream}
+%    group inside the \textt{tabu} environment.
 %
 %    \begin{macrocode}
-\expandafter\def\csname NC@rewrite@\string\usetabu\endcsname#1{%
+\tabu@newcolumntype \usetabu #1{%
    \ifx\\#1\\\tabu@saveerr{}\else
       \@ifundefined{tabu@saved@\string#1}
          {\tabu@saveerr{#1}}
          {\let\tabu@rewrite@X \tabu@rewrite@Xrestore
-         \def\tabu@temp{\xdef\tabu@usetabu{%
-            \col@sep \the\col@sep\relax
-            \arrayrulewidth \the\arrayrulewidth\relax
-            \@tempdima \ht\@arstrutbox \advance\@tempdima -\extrarowheight
-            \extrarowheight \the\extrarowheight\relax
-            \advance\@tempdima \extrarowheight
-            \ht\@arstrutbox \@tempdima
-            \extratabsurround \the\extratabsurround\relax
-            \doublerulesep \the\doublerulesep\relax}}%
-         \aftergroup \tabu@usetabu
-         \csname tabu@saved@\string#1\expandafter\endcsname}%
+          \csname tabu@saved@\string#1\expandafter\endcsname\expandafter\z@}%
    \fi
 }% \NC@rewrite@\usetabu
-\expandafter\def\csname NC@find@\string\usetabu\endcsname#1\usetabu{\NC@{#1}}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\preamble (new column type)}
+%
+%    \cs{preamble} is defined as a \textt{tabu} new column type: loaded only inside the \cs{@mkpream}
+%    group inside the \textt{tabu} environment.
+%
+%    \begin{macrocode}
+\tabu@newcolumntype \preamble #1{%
+   \ifx\\#1\\\tabu@saveerr{}\else
+      \@ifundefined{tabu@saved@\string#1}
+         {\tabu@saveerr{#1}}
+         {\csname tabu@saved@\string#1\expandafter\endcsname\expandafter\@ne}%
+   \fi
+}% \NC@rewrite@\preamble
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -1720,27 +2079,18 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    of the \textt X column occurs only inside the group where \cs{@mkpream} does its job).
 %
 %    \begin{macrocode}
-\expandafter\def\csname NC@rewrite@\string\tabu@rewritefirst\endcsname{%
-   \ifx\tabu@lines\relax
-   \NC@list\expandafter{\expandafter\NC@do \expandafter\usetabu
-                        \NC@do X\NC@do\tabu@rewritelast}%
-   \else
-   \NC@list\expandafter{\expandafter\NC@do \expandafter\usetabu
-                        \expandafter\NC@do \expandafter|\tabu@NC@list
-                        \NC@do X\NC@do\tabu@rewritelast}%
-      \tabu@lines % defines NC@rewrite@| for tabu only (inside @mkpream group)
-   \fi
-   \let\save@decl \tabu@save@decl % inversion of tokens in text mode
-   \let\NC@rewrite@X \tabu@NC@rewrite@X
-   \aftergroup \tabu@global@temp
+\tabu@newcolumntype \tabu@rewritefirst{%
+   \tabu@X@cols \z@  \let\NC@rewrite@X \tabu@NC@rewrite@X
+   \let\tabu@dimexpr \relax \aftergroup \tabu@global@temp
+   \aftergroup \tabu@restore@NC@list
+   \NC@list{\NC@do\usetabu \NC@do\preamble \NC@do *}%
+   \tabu@lines % defines NC@rewrite@| for tabu only (inside @mkpream group)
+   \NC@list\expandafter{\the\NC@list \NC@do X\NC@do\tabu@rewritelast}%
+   \ifcat$\d@llarend\else
+      \let\save@decl \tabu@save@decl \fi % no inversion of tokens in text mode
    \NC@find \tabu@rewritelast
 }% NC@rewrite@\tabu@rewritefirst
-\expandafter\def\csname NC@find@\string\tabu@rewritefirst\endcsname
-                                          #1\tabu@rewritefirst{\NC@{#1}}
-\def\tabu@rewritefirst{%
-   \edef\tabu@NC@list{\the\NC@list}%
-   \NC@list{\NC@do \tabu@rewritefirst \NC@do *}%
-}% \tabu@rewritefirst
+\def\tabu@restore@NC@list{\NC@list\expandafter{\tabu@NC@list}}
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -1758,32 +2108,48 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    Otherwise, we must insert \textt{!\M*{\cs{extracolsep}\cs{@flushglue}}} in order to keep the margin.
 %
+%    \cs{tabu@rewritelast} column type is loaded by \cs{tabu@rewritefirst} column type, only inside the \cs{@mkpream}
+%    group inside the \textt{tabu} environment.
+%
 %    \begin{macrocode}
-\expandafter\def\csname NC@rewrite@\string\tabu@rewritelast\endcsname{%
-   \global\NC@list\expandafter{\tabu@NC@list}%
-   \futurelet \tabu@temp \tabu@rewritelast
-}% \NC@rewrite@\tabu@rewritelast
-\expandafter\def\csname NC@find@\string\tabu@rewritelast\endcsname
-                                          #1\tabu@rewritelast{\NC@{#1}}
-\def\tabu@rewritelast{%
+\tabu@newcolumntype \tabu@rewritelast{%
+   \NC@list\expandafter{\tabu@NC@list}%
+   \let\tabu@next \NC@find
    \ifx \@halignto\relax   % found a X column
-      \let\tabu@temp \@empty
       \ifx \tabu@halignto\relax % X column measure
+         \tabu@global@Xnested
+         \iftabu@negcoef \aftergroup\tabu@negcoeftrue \fi
          \aftergroup \tabu@prep@TRIAL
       \else \aftergroup \tabu@setup@everycr
       \fi
    \else
-      \ifdim \tabu@target=\z@ \let\tabu@temp \@empty
-      \else
-         \if |\noexpand\tabu@temp\def\tabu@temp{@{\extracolsep\@flushglue}}\else
-         \if !\noexpand\tabu@temp\def\tabu@temp{@{\extracolsep\@flushglue}}\else
-                                 \def\tabu@temp{!{\extracolsep\@flushglue}}\fi\fi
-      \fi
-      \aftergroup\tabu@setup@everycr
+      \aftergroup \tabu@setup@everycr
+      \ifdim \tabu@target=\z@ \else
+         \let\tabu@next \tabu@rewritelast \fi % <need \extracolsep ?>
    \fi
    \let\@halignto \tabu@halignto
-   \expandafter\NC@find \tabu@temp
+   \tabu@next
+}% \NC@rewrite@\tabu@rewritelast
+\def\tabu@rewritelast{\futurelet\tabu@temp \tabu@rewrite@last}
+\def\tabu@rewrite@last{%
+   \ifx \tabu@temp\@sptoken
+      \expandafter\tabu@gobblespace \expandafter\tabu@rewritelast
+   \else
+      {\endlinechar\m@ne\scantokens{\let\x |}%
+      \expandafter}\ifx \x\tabu@temp
+         \def\tabu@next {\NC@find @{\extracolsep\@flushglue}}\else
+      {\endlinechar\m@ne\scantokens{\let\x !}%
+      \expandafter}\ifx \x\tabu@temp
+         \def\tabu@next {\NC@find @{\extracolsep\@flushglue}}\else
+         \def\tabu@next {\NC@find !{\extracolsep\@flushglue}}\fi\fi
+      \expandafter\tabu@next
+   \fi
 }% \tabu@rewritelast
+\def\tabu@global@Xnested{\global\expandafter\let
+         \csname tabu@global@X\the\tabu@nested\endcsname\tabu@global@X
+   \aftergroup\let \aftergroup\tabu@global@X
+   \expandafter\aftergroup \csname tabu@global@X\the\tabu@nested\endcsname
+}% \tabu@global@Xnested
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -1802,20 +2168,23 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    \begin{macro}{\tabu@nowrite}
 %
-%    A trick to fobidd \cs{write} when a trial is done on the \cs{halign}.
-%    (Copied from D. Carlisle's \xpackage{tabularx} code.)
+%    A trick (from the \TeX-book to forbidd \cs{write} when a trial is done on the \cs{halign}.
 %
 %    \begin{macrocode}
-\def\tabu@nowrite{% cancels a \write command (tabularx method)
-   \begingroup
-     \def\let{\afterassignment\endgroup\toks@}%
-        \afterassignment\let\count@
-}% \tabu@nowrite
+\def\tabu@nowrite#1#{{\afterassignment}\toks@}
 \let\tabu@write\write
+\let\tabu@immediate\immediate
+\protected\def\tabu@GenericError{\begingroup
+   \def\immediate\write{\aftergroup\endgroup
+      \tabu@immediate\tabu@write}\tabu@GenericErrorORI}%
+\let\tabu@GenericErrorORI \GenericError
+\protected\def\tabu@warn{\begingroup
+   \def\immediate\write{\aftergroup\endgroup
+      \tabu@immediate\tabu@write}\PackageWarning{tabu}}
 %    \end{macrocode}
 %    \end{macro}
 %
-% \subsection{\cs{tabu} and \cs{endtabu}}
+% \subsection{\cs{tabu}, \cs{endtabu}, \cs{longtabu} and \cs{endlontabu}}
 %
 %    \begin{macro}{\tabu}
 %
@@ -1827,10 +2196,19 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    \begin{macrocode}
 \def\tabu{%
-   \ifmmode \def\endtabu{\endarray}%
-   \else    \def\endtabu{\endtabular}\fi
+   \ifmmode \def\tabu@{\array}\def\endtabu{\endarray}%
+   \else    \def\tabu@{\tabular}\def\endtabu{\endtabular}\fi
    \tabu@setup \tabu@settarget
 }% \tabu
+\def\longtabu{%
+   \ifmmode\PackageError{tabu}{longtabu not allowed in math mode}\fi
+   \def\tabu@{\longtable}\def\endlongtabu{\endlongtable}%
+   \let\tabu@arrayleft@measure \tabu@long@arrayleft@measure
+   \let\tabu@endTRIAL \tabu@long@endTRIAL
+   \tabu@setup \tabu@settarget
+}% \longtabu
+\def\tabu@nolongtabu{\PackageError{tabu}
+   {longtabu requires the longtable package}\@ehd}
 %    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
@@ -1845,54 +2223,43 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    \begin{macrocode}
 \def\tabu@setup{%
-   \let\adl@xarraydashrule \tabu@adl@xarraydashrule % <fix> arydshln
-   \let\adl@act@endpbox \tabu@adl@act@endpbox       % <fix> arydshln
-   \let\adl@act@@endpbox \tabu@adl@act@endpbox      % <fix> arydshln
-   \let\@preamerror \@preamerr                      % <fix> arydshln
-   \let\endarray \tabu@endarray          % <fix> colortbl & arydshln (delarray)
+   \tabu@adl@fix \let\endarray \tabu@endarray % <fix> colortbl & arydshln (delarray)
    \let\tabu@global@temp \@empty \let\tabu@global@X \@empty
-   \ifx\verbatim \tabu@sanitizetext
-         \tabu@nestedtrue
-         \def\tabu@aligndefault{t}\def\tabudefaulttarget{\linewidth}%
-   \else \tabu@nestedfalse
-         \def\tabu@aligndefault{c}%
-         \global\tabu@footnotes{}%
-         \aftergroup\the\aftergroup\tabu@footnotes
-         \ifdim\parindent>\z@ \ifx\linewidth\tabudefaulttarget
-         \everypar\expandafter{%                    % correction for indentation
+   \ifx \verbatim\tabu@sanitizetext      % <nested tabu>
+      \tabu@setup@saveglobal
+      \advance\tabu@nested \@ne
+      \def\tabu@aligndefault{t}\let\tabudefaulttarget \linewidth
+   \else
+      \def\tabu@aligndefault{c}\edef\tabu@hfuzz {\the\hfuzz}%
+      \global\tabu@footnotes{}\aftergroup\the\aftergroup\tabu@footnotes
+      \ifdim\parindent>\z@ \ifx\linewidth\tabudefaulttarget
+         \everypar\expandafter{%         % correction for indentation
             \the\everypar\everypar\expandafter{\the\everypar}%
             \setbox\z@=\lastbox
             \ifdim\wd\z@>\z@ \advance\linewidth -\wd\z@\fi
             \box\z@
             }%
-         \fi\fi
+      \fi\fi
    \fi
-   \let\@footnotetext \tabu@footnotetext
-   \let\@xfootnotetext\tabu@xfootnotetext
-   \let\@xfootnote \tabu@xfootnote
-   \let\centering \tabu@centering
-   \let\raggedright \tabu@raggedright
-   \let\raggedleft \tabu@raggedleft
-   \let\@trivlist \tabu@trivlist           %<restore \\=\@centercr inside lists>
-   \let\tabudecimal \tabu@tabudecimal
-   \let\verbatim \tabu@sanitizetext
-   \let\fbox \tabu@fbox
-   \let\prepnext@tok \tabu@prepnext@tok            % <for rowfont and tabucline>
-   \let\rowfont \tabu@rowfont
+   \let\@footnotetext \tabu@footnotetext \let\@xfootnotetext \tabu@xfootnotetext
+   \let\@xfootnote    \tabu@xfootnote    \let\centering      \tabu@centering
+   \let\raggedright   \tabu@raggedright  \let\raggedleft     \tabu@raggedleft
+   \let\@trivlist     \tabu@trivlist     %<restore \\=\@centercr inside lists>
+   \def\tabudecimal   {\tabu@tabudecimal}\let\verbatim       \tabu@sanitizetext
+   \let\fbox          \tabu@fbox         \let\rowfont        \tabu@rowfont
+   \let\prepnext@tok  \tabu@prepnext@tok %<for \rowfont and \tabucline>
    \everycr{}\let\tabu@everycr \everycr
-   \tabu@spreadfalse \tabu@measuringfalse
-   \edef\tabu@hfuzz{\ifdim\hfuzz<.1\p@ .1\p@\else\the\hfuzz\fi}%
-   \tabu@rewritefirst
+   \tabu@spreadfalse  \tabu@measuringfalse \tabu@negcoeffalse
+   \edef\tabu@NC@list{\the\NC@list}\NC@list{\NC@do\tabu@rewritefirst \NC@do *}%
 }% \tabu@setup
-\def\tabu@save@decl{% no inversion on tokens when not in math mode
-   \ifcat$\d@llarend
-      \toks\count@\expandafter\expandafter\expandafter{%
-               \expandafter\@nextchar \the\toks\count@}%
-   \else
-      \toks\count@\expandafter\expandafter\expandafter{%
-         \expandafter\the\expandafter\toks\expandafter\count@\@nextchar}%
-   \fi
-}% \tabu@save@decl
+\def\tabu@setup@saveglobal{%
+   \expandafter\xdef\csname tabu@global@\the\tabu@nested\endcsname{%
+      \global\tabu@X@cols \the\tabu@X@cols\relax
+      \global\tabu@naturalX \the\tabu@naturalX\relax
+      \gdef\noexpand\tabu@naturalX@min {\tabu@naturalX@min}%
+      \gdef\noexpand\tabu@naturalX@max {\tabu@naturalX@max}}%
+      \expandafter\aftergroup\csname tabu@global@\the\tabu@nested\endcsname
+}% \tabu@setup@saveglobal
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -1911,47 +2278,58 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
            \if t\@let@token 2\else
            \if s\@let@token 3\else
            \m@ne\fi\fi\fi\fi\fi\relax
-       \expandafter\tabu@begin
-   \or \expandafter\tabu@gobblespace\expandafter\tabu@settarget
-   \or \expandafter\tabu@to
-   \or \expandafter\tabu@spread
-   \else\expandafter\tabu@begin
+         \expandafter\tabu@begin
+   \or   \expandafter\tabu@gobblespace\expandafter\tabu@settarget
+   \or   \expandafter\tabu@to
+   \or   \expandafter\tabu@spread
+   \else \expandafter\tabu@begin
    \fi
 }% \tabu@sett@rget
 \def\tabu@to to{\def\@halignto{to}\tabu@gettarget}
 \def\tabu@spread spread{\tabu@spreadtrue\def\@halignto{spread}\tabu@gettarget}
-\def\tabu@gettarget{\afterassignment\tabu@linegoaltarget\tabu@target}
-\def\tabu@linegoaltarget{\futurelet\tabu@temp\tabu@linegoal@target}
-\def\tabu@linegoal@target{\ifx\tabu@temp\LNGL@setlinegoal
-   \LNGL@setlinegoal
-      \expandafter\expandafter\expandafter \tabu@begin
-      \expandafter\@gobble
-   \else \expandafter\tabu@begin
-   \fi
+\def\tabu@gettarget {\afterassignment\tabu@linegoaltarget \tabu@target}
+\def\tabu@linegoaltarget {\futurelet\tabu@temp \tabu@linegoal@target}
+\def\tabu@linegoal@target {%
+   \ifx \tabu@temp\LNGL@setlinegoal
+        \LNGL@setlinegoal \expandafter \@firstoftwo \fi % @gobbles \LNGL@setlinegoal
+   \tabu@begin
 }% \tabu@linegoal@target
-\def\tabu@begin#1#{%
-   \edef\@halignto{\ifdim\tabu@target>\z@ \@halignto\the\tabu@target\fi}%
+\def\tabu@begin #1#{%
+   \edef\@halignto {\ifdim\tabu@target>\z@ \@halignto\the\tabu@target\fi}%
    \let\tabu@halignto \@halignto
-   \expandafter\@testopt \expandafter\tabu@@begin \tabu@aligndefault #1\@nil
+   \@testopt \tabu@@begin \tabu@aligndefault #1\@nil
 }% \tabu@begin
-\def\tabu@@begin[#1]#2\@nil#3{%
-   \edef\tabu@align{#1}%
-   \edef\tabu@saved{%
+\def\tabu@@begin [#1]#2\@nil#3{%
+   \tabu@preparesave{#3}%     <for \savetabu>
+   \def\tabu@align {#1}%
+   \tabu@ [{\tabu@align}]#2{\tabu@rewritefirst #3}%
+}% \tabu@@begin
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+%    \begin{macro}{\tabu@preparesave}
+%
+%    This macro temporarily save the \textt{tabu} preamble and the settings
+%    for \cs{arrayrulewidth}, \cs{extrarowheight} \etc.
+%
+%    Those values are retrieved by \cs{savetabu}, if invoked inside the \textt{tabu}.
+%
+%    \begin{macrocode}
+\def\tabu@preparesave #1{%
+   \edef\tabu@savedparam{%
       \ifmmode \col@sep \the\arraycolsep
       \else    \col@sep \the\tabcolsep     \fi\relax
-      \arrayrulewidth \the\arrayrulewidth\relax
-      \extrarowheight \the\extrarowheight\relax
+      \arrayrulewidth   \the\arrayrulewidth\relax
+      \doublerulesep    \the\doublerulesep\relax
+      \extrarowheight   \the\extrarowheight\relax
       \extratabsurround \the\extratabsurround\relax
-      \doublerulesep \the\doublerulesep\relax}%
-   \expandafter\def\expandafter\tabu@saved\expandafter{\tabu@saved
-            \tabu@temp \edef\tabu@halignto{to\the\tabu@target}\NC@find #3}%
-   \ifmmode \expandafter\array
-   \else    \expandafter\tabular
-   \fi      [{#1}]#2{\tabu@rewritefirst #3}%
-}% \tabu@@begin
+      \def\noexpand\arraystretch {\arraystretch}%
+      \iftabu@colortbl \minrowclearance\the\minrowclearance\relax \fi}%
+   \def\tabu@savedpream {\edef\tabu@halignto{to\the\tabu@target}\NC@find #1}%
+}% \tabu@preparesave
 %    \end{macrocode}
 %    \end{macro}
-%    \end{macro}
 %
 %
 % \subsection{Footnotes inside \textt{tabu}}
@@ -1970,13 +2348,13 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    The macros in case \xpackage{hyperref} is not used, or used with the option \textt{hyperfootnotes=false}:
 %
 %    \begin{macrocode}
-\long\def\tabu@footnotetext#1{%
+\long\def\tabu@footnotetext #1{%
    \edef\@tempa{\the\tabu@footnotes
       \noexpand\footnotetext [\the\csname c@\@mpfn\endcsname]}%
-   \global\tabu@footnotes\expandafter{\@tempa{#1}}}%
-\long\def\tabu@xfootnotetext[#1]#2{%
+   \global\tabu@footnotes\expandafter{\@tempa {#1}}}%
+\long\def\tabu@xfootnotetext [#1]#2{%
   \global\tabu@footnotes\expandafter{\the\tabu@footnotes
-                           \footnotetext[{#1}]{#2}}}
+                              \footnotetext [{#1}]{#2}}}
 \let\tabu@xfootnote \@xfootnote
 %    \end{macrocode}
 %    \end{macro}
@@ -1988,14 +2366,14 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    \begin{macrocode}
 \long\def\tabu@Hy@ftntext{\tabu@Hy@ftntxt {\the \c@footnote }}
-\long\def\tabu@Hy@xfootnote[#1]{%
+\long\def\tabu@Hy@xfootnote [#1]{%
    \begingroup
       \value\@mpfn #1\relax
       \protected@xdef \@thefnmark  {\thempfn}%
    \endgroup
    \@footnotemark \tabu@Hy@ftntxt {#1}%
 }% \tabu@Hy@xfootnote
-\long\def\tabu@Hy@ftntxt#1#2{%
+\long\def\tabu@Hy@ftntxt #1#2{%
    \edef\@tempa{%
       \the\tabu@footnotes
       \begingroup
@@ -2008,39 +2386,39 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
           }%
       }%
       \global\tabu@footnotes\expandafter{%
-          \@tempa{#2}%
+          \@tempa {#2}%
         \endgroup
       }%
 }% \tabu@Hy@ftntxt
-\long\def\tabu@Hy@footnotetext#1#2{%
+\long\def\tabu@Hy@footnotetext #1#2{%
    \H@@footnotetext{%
       \ifHy@nesting
-         \hyper@@anchor{#1}{#2}%
+         \hyper@@anchor {#1}{#2}%
       \else
          \Hy@raisedlink{%
-            \hyper@@anchor{#1}{\relax}%
+            \hyper@@anchor {#1}{\relax}%
          }%
-         \def\@currentHref{#1}%
-         \let\@currentlabelname\@empty
+         \def\@currentHref {#1}%
+         \let\@currentlabelname \@empty
          #2%
       \fi
    }%
 }% \tabu@Hy@footnotetext
 \AtBeginDocument{%
-   \@ifpackageloaded{hyperref}
-      {\ifHy@hyperfootnotes
-         \let\tabu@footnotetext \tabu@Hy@ftntext
-         \let\tabu@xfootnote    \tabu@Hy@xfootnote
-       \fi}
-      {}%
-}%
+   \csname\ifcsname ifHy@hyperfootnotes\endcsname
+    ifHy@hyperfootnotes\else iffalse\fi\endcsname
+      \let\tabu@footnotetext \tabu@Hy@ftntext
+      \let\tabu@xfootnote    \tabu@Hy@xfootnote
+   \fi
+}
 %    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
 %
 %
-%
-% \subsection{Flow chart of expansion} ^^A\enlargethispage{\baselineskip}
+% \clearpage
+% \subsection{Flow chart of expansion}
+% \label{Flow chart of expansion}
 %
 % \subsubsection(case: tabu, tabu to and tabu spread){General case: tabu, tabu to and tabu spread}
 %
@@ -2233,11 +2611,34 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \end{itemize}
 %
 %    \begin{macrocode}
-\def\tabu@rewrite@X#1{\tabu@Xarg{#1}%
-   \iftabu@spread \tabu@rewrite@Xspread
-   \else          \tabu@rewrite@Xto
+\def\tabu@rewrite@X #1{\tabu@Xarg {#1}%
+   \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \relax
+   \iftabu@measuring % not the first X column found in preamble
+      \edef\tabu@global@X {\tabu@global@X
+            \advance\tabu@X@cols \@ne
+            \def\csname tabu@X\the\tabu@X@cols\endcsname {\strip@pt\tabu@X@sum}%
+            \advance\tabu@X@sum \the\tabu@X@sum\relax}%
+   \else % first X column found in preamble
+      \tabu@measuringtrue
+      \iftabu@spread \tabu@spreadtarget\tabu@target \tabu@target\z@
+      \else          \tabu@spreadtarget \z@ \fi
+      \ifdim\tabu@target=\z@
+         \setlength\tabu@target \tabudefaulttarget
+         \tabu@message{(tabu) Default target:
+            \ifx\tabudefaulttarget\linewidth\string\linewidth
+            \else\ifx\tabudefaulttarget\linegoal\string\linegoal
+            \fi\fi=\the\tabu@target \on@line, page \the\c@page}\fi
+      \tabu@message{\tabu@titles}%
+      \edef\tabu@global@X {\tabu@global@X
+         \tabu@X@cols \@ne
+         \def\csname tabu@X1\endcsname{\strip@pt\tabu@X@sum}%
+         \tabu@X@sum  \the\tabu@X@sum\relax
+         \tabu@target \the\tabu@target\relax
+         \tabu@spreadtarget \the\tabu@spreadtarget\relax}%
+      \let\tabu@halignto \relax
    \fi
 }% \tabu@rewrite@X
+\let\tabu@@rewrite@X \tabu@rewrite@X
 %    \end{macrocode}
 %
 %    \begin{macro}{\tabu@rewrite@Xnested}
@@ -2249,96 +2650,43 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    This macro replaces \cs{tabu@rewrite@X} in the case of \cs{usetabu}.
 %
 %    \begin{macrocode}
-\def\tabu@rewrite@Xnested#1{\in@ ${#1}\ifin@
-   \def\tabucolX@spec{>{$}p{\tabucolX}<{$}}\else
-   \def\tabucolX@spec{p{\tabucolX}}\fi}
-\def\tabu@rewrite@Xrestore#1{\tabu@Xarg{#1}\let\tabucolX@spec\tabu@temp}%
+\def\tabu@rewrite@Xnested #1{\in@ ${#1}\ifin@
+   \def\tabucolX@rw {>{$}p{\tabucolX}<{$}}\else
+   \def\tabucolX@rw {p{\tabucolX}}\fi}
+\def\tabu@rewrite@Xrestore #1{\tabu@gobbleopt{\def\tabucolX@rw{l}}}
 %    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
 %    \end{macro}
 %
 %
-%    \begin{macro}{\tabu@rewrite@Xto}
-%
-%    The setup for trial is not the same in case of ``\textt{tabu to}'' and ``\textt{tabu spread}''.
-%
-%    The important thing is:\, \cs{aftergroup}\cs{tabu@prep@TRIAL}.
-%
-%    \begin{macrocode}
-\def\tabu@rewrite@Xto{%
-   \iftabu@measuring % not the first X column found in preamble
-      \xdef\tabu@global@X {\tabu@global@X
-         \advance\tabu@X@sum \the\tabu@X@sum\relax}%
-   \else % first X column found in preamble
-      \tabu@measuringtrue
-      \ifdim\tabu@target=\z@
-         \setlength \tabu@target \tabudefaulttarget
-      \fi
-      \xdef\tabu@global@X{%
-         \tabu@X@sum \the\tabu@X@sum\relax
-         \tabu@target \the\tabu@target\relax}%
-      \let\tabu@halignto \relax
-   \fi
-}% \tabu@rewrite@Xto
-%    \end{macrocode}
-%    \end{macro}
-%
-%    \begin{macro}{\tabu@rewrite@Xspread}
-%
-%    This macro is used instead of \cs{tabu@rewrite@Xto} for \textt X columns with ``\textt{tabu spread}''.
-%
-%    \begin{macrocode}
-\def\tabu@rewrite@Xspread{% tabu spread with X columns: need to store each coef
-   \iftabu@measuring % not the first X column found in preamble
-      \advance\tabu@X@cols \@ne
-      \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \relax
-      \xdef\tabu@global@X {\tabu@global@X
-            \advance\tabu@X@cols\@ne
-            \advance\tabu@X@sum \the\tabu@X@sum\relax
-            \def\csname tabu@X\the\tabu@X@cols\endcsname{\strip@pt\tabu@X@sum}}%
-   \else % first X column found in preamble
-      \tabu@measuringtrue
-      \tabu@X@cols \@ne  \tabu@spreadtarget=\tabu@target
-      \setlength \tabu@target \tabudefaulttarget
-      \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \relax
-      \xdef\tabu@global@X {%
-         \tabu@X@cols \@ne
-         \tabu@X@sum \the\tabu@X@sum\relax
-         \tabu@target \the\tabu@target\relax
-         \tabu@spreadtarget \the\tabu@spreadtarget\relax
-         \def\csname tabu@X\the\tabu@X@cols\endcsname{\strip@pt\tabu@X@sum}}%
-      \let\tabu@halignto \relax
-   \fi
-}% \tabu@rewrite@Xspread
-%    \end{macrocode}
-%    \end{macro}
-%
-%
 %    \begin{macro}{\tabu@Xarg}
+%    \begin{macro}{\tabu@Xparse}
+%    \begin{macro}{\tabucolX@do}
 %
 %    A tedious (and fastidious) macro to parse the optional argument of \textt X columns. The aim is to built
-%    \cs{tabucolX@spec} which expands to the column specification:
+%    \cs{tabucolX@rw} which expands to the column specification:
 %
 %    {\centering \textt{>\M*{alignment} p \emph{or} m \emph{or} b \M*{\cs{dimexpr} coef \cs{tabucolX}\cs{relax}}}\par}
 %
-%    After that \xfile{array.sty} make it easy:\, \cs{expandafter}\cs{NC@find}\cs{tabucolX@spec}
+%    After that \xfile{array.sty} make it easy:\, \cs{expandafter}\cs{NC@find}\cs{tabucolX@rw}
 %
 %    \begin{macrocode}
 \def\tabu@Xarg#1{%
-   \ifx\\#1\\%    <shortcut when no option>
-      \tabu@X@sum \p@
-      \def\tabucolX@spec{p{\tabucolX}}%
-      \edef\tabu@temp{p{\the\tabucolX}}%  <required for \usetabu>
-   \else
-      \tabu@X@sum \z@
-      \let\tabucolX@align \@empty
-      \let\tabucolX@spec \@empty
-      \let\tabu@Xmath \relax
-      \tabu@Xparse {}#1\relax\@nnil
-   \fi
+  \advance\tabu@X@cols \@ne
+  \tabu@wdlet\tabu@X@cols \z@
+  \ifx\\#1\\%    <shortcut when no option>
+     \tabu@X@sum \p@
+     \edef\tabucolX@rw {p{\tabu@dimexpr{\the\tabu@X@cols}{\tabucolX}}}%
+     \edef\tabu@temp {p{\the\tabucolX}}%  <required for \usetabu>
+  \else
+     \tabu@X@sum \z@
+     \let\tabucolX@align \@empty \let\tabucolX@rw \@empty
+     \let\tabu@Xmath     \@empty \let\tabu@temp     \@empty
+     \tabu@Xparse {}#1\relax\@nnil
+  \fi
 }% \tabu@Xarg
-\def\tabu@Xparse#1{\futurelet\@let@token\tabu@Xtest}
+\def\tabu@Xparse #1{\futurelet\@let@token \tabu@Xtest}
 \expandafter\def\expandafter\tabu@Xparsespace\space{\tabu@Xparse{}}
 \def\tabu@Xtest{%
    \ifcase \ifx \@nnil\@let@token \z@ \else
@@ -2350,28 +2698,29 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
            \if l\@let@token 4\else
            \if c\@let@token 5\else
            \if r\@let@token 6\else
-           \if .\@let@token 7\else
-           \ifx \@sptoken\@let@token 8\else
-           \if L\@let@token 9\else
-           \if C\@let@token 10\else
-           \if R\@let@token 11\else
+           \if L\@let@token 7\else
+           \if C\@let@token 8\else
+           \if R\@let@token 9\else
+           \ifx \@sptoken\@let@token 10\else
+           \if .\@let@token 11\else
+           \if -\@let@token 11\else
            \ifcat $\@let@token 12\else
-           13\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\relax
-       \tabucolX@do \expandafter\remove@to@nnil
-   \or \tabu@Xcolspec{p}%
-   \or \tabu@Xcolspec{m}%
-   \or \tabu@Xcolspec{b}%
-   \or \tabu@Xalign{>{\raggedright}}%
-   \or \tabu@Xalign{>{\centering}}%
-   \or \tabu@Xalign{>{\raggedleft}}%
-   \or \expandafter\tabu@Xcoef
-   \or \expandafter\tabu@Xparsespace
-   \or \tabu@Xalign{>{\RaggedRight}}%
-   \or \tabu@Xalign{>{\Centering}}%
-   \or \tabu@Xalign{>{\RaggedLeft}}%
-   \or \let\tabu@Xmath=$\expandafter\tabu@Xparse
+           13\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\relax
+       \tabucolX@do \expandafter \remove@to@nnil
+   \or \tabu@Xtype {p}%
+   \or \tabu@Xtype {m}%
+   \or \tabu@Xtype {b}%
+   \or \tabu@Xalign \raggedright
+   \or \tabu@Xalign \centering
+   \or \tabu@Xalign \raggedleft
+   \or \tabu@Xalign \RaggedRight
+   \or \tabu@Xalign \Centering
+   \or \tabu@Xalign \RaggedLeft
+   \or \expandafter \tabu@Xparsespace
+   \or \expandafter \tabu@Xcoef
+   \or \let\tabu@Xmath=$\expandafter \tabu@Xparse
    \or \tabu@Xcoef{}%
-   \else \expandafter\tabu@Xparse
+   \else\expandafter \tabu@Xparse
    \fi
 }% \tabu@Xtest
 \def\tabu@Xalign#1{%
@@ -2379,42 +2728,51 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
       {Duplicate horizontal alignment specification}\fi
    \def\tabucolX@align{#1}\expandafter\tabu@Xparse
 }% \tabu@Xalign
-\def\tabu@Xcolspec#1{%
-   \ifx\tabucolX@spec\@empty\else \PackageWarning{tabu}
+\def\tabu@Xtype#1{%
+   \ifx \tabucolX@rw\@empty \else \PackageWarning{tabu}
       {Duplicate vertical alignment specification}\fi
-   \def\tabucolX@spec{#1}\expandafter\tabu@Xparse
-}% \tabu@Xcolspec
-\def\tabu@Xcoef#1{\def\@tempa{#1}%
-   \afterassignment\tabu@Xc@ef \tabu@cnt
+   \def\tabucolX@rw{#1}\expandafter\tabu@Xparse
+}% \tabu@Xtype
+\def\tabu@Xcoef#1{\edef\tabu@temp{\tabu@temp#1}%
+   \afterassignment\tabu@Xc@ef \tabu@cnt\number\if-#10\fi
 }% \tabu@Xcoef
 \def\tabu@Xc@ef{%
-   \advance\tabu@X@sum \@tempa\the\tabu@cnt\p@
+   \advance\tabu@X@sum \tabu@temp\the\tabu@cnt\p@
    \tabu@Xparse{}%
 }% \tabu@Xc@ef
 \def\tabucolX@do{%
-   \ifx\tabucolX@spec\@empty \def\tabucolX@spec{p}\fi
-   \ifdim \tabu@X@sum=\z@ \tabu@X@sum \p@\fi
+   \ifx\tabucolX@rw\@empty \def\tabucolX@rw{p}\fi
+   \ifdim\tabu@X@sum<\z@ \tabu@negcoeftrue
+                         \tabu@X@sum \m@ne\tabu@X@sum
+                         \tabu@wdlet \tabu@X@cols \p@
+   \else \ifdim \tabu@X@sum=\z@ \tabu@X@sum \p@ \fi
+   \fi
    \begingroup
-      \edef\tabucolX@spec##1{\tabucolX@spec{##1}}%
-      \edef\tabu@temp{\dimexpr\strip@pt\tabu@X@sum \tabucolX \relax}%
-      \toks@\expandafter{\tabucolX@align}%
-      \edef\x{%
-         \def\noexpand\tabu@temp{%
-            \ifx \tabu@Xmath\relax\else >{$}\fi
-            \the\toks@ \tabucolX@spec{\the\tabu@temp}%
-            \ifx \tabu@Xmath\relax\else <{$}\fi}%
-         \def\noexpand\tabucolX@spec{%
-            \ifx \tabu@Xmath\relax\else >{$}\fi
-            \the\toks@ \tabucolX@spec{\tabu@temp}%
-            \ifx \tabu@Xmath\relax\else <{$}\fi}%
-      }\expandafter\endgroup\x
+      \toks@\expandafter {\tabucolX@align}%
+      \edef\tabu@temp {\strip@pt\tabu@X@sum \tabucolX}%
+      \edef\tabucolX@rw##1{%
+         \ifx$\tabu@Xmath>{\noexpand\the\toks@ $}\else
+         \ifx \tabucolXalign\@empty \else
+            >{\noexpand\the\toks@}\fi\fi
+            \tabucolX@rw{##1}%
+         \ifx$\tabu@Xmath<{$}\fi}%
+      \edef\x{\endgroup
+         \def\noexpand\tabu@temp {\tabucolX@rw{\the\dimexpr\tabu@temp}}%
+         \def\noexpand\tabucolX@rw{%
+            \tabucolX@rw{\tabu@dimexpr{\the\tabu@X@cols}{\tabu@temp}}}%
+         }\x
 }% \tabucolX@do
+\def\tabu@dimexpr#1#2{%
+   \ifdim \tabu@wd{#1}>\p@
+      \ifdim \tabu@wd{#1}<#2 \tabu@wd{#1}\else#2\fi\else #2\fi
+}% \tabu@dimexpr
 %    \end{macrocode}
 %    \end{macro}
+%    \end{macro}
+%    \end{macro}
 %
-% \subsection(Before trials){Before trials to reach the target}
 %
-% \subsubsection{Trial setup after \cs{@mkpream}}
+% \subsection(Before trials){Before trials to reach the target: setup after \cs{@mkpream}}
 %
 %    \begin{macro}{\tabu@prep@TRIAL}
 %
@@ -2428,41 +2786,42 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \begin{macrocode}
 \def\tabu@prep@TRIAL{%
    \let\tabu@savedpreamble \@preamble
-   \def\savetabu {\tabu@saveX}%
-   \begingroup\iffalse{\fi\ifnum0=`}\fi
+   \begingroup \iffalse{\fi \ifnum0=`}\fi
       \tabu@setup@TRIAL
-      \iftabu@spread % first trial only
+      \tabucolX \tabu@target
+      \ifcase 0\iftabu@negcoef \else\iftabu@spread \else 1\fi\fi
          \advance\tabu@X@cols \@ne
          \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \@undefined
-         \tabu@X@cols \z@ \tabu@naturalX \z@ \tabucolX \z@
-         \let\tabu@naturalX@max \z@
-         \let\tabu@naturalX@min \z@
+         \tabu@X@cols \z@
+         \def\tabu@naturalX@max {\z@}%
+         \def\tabu@naturalX@min {\z@}%
          \let\tabu@startpboxORI \@startpbox
-         \let\@startpbox \tabu@spread@startpbox
-      \else
-         \tabucolX = \tabu@target
+         \let\@startpbox \tabu@measure@startpbox
       \fi
-      \tabu@cnt \z@  % number of trials
-      \def\tabu@lasttry{\m@ne\p@}%
+      \def\tabu@lasttry{\m@ne\p@}\tabu@cnt \z@  % number of trials
       \tabu@arrayleft@measure
 }% \tabu@prep@TRIAL
 %    \end{macrocode}
+%    \end{macro}
 %
+%    \begin{macro}{\tabu@setup@TRIAL}
 %    \begin{macrocode}
-\def\tabu@setup@TRIAL{\tabu@global@X
+\def\tabu@setup@TRIAL{\tabu@global@X \let\tabu@global@X \@empty
+   \let\@halignto \@empty  \tabu@naturalX \z@
+   \tabu@savecounters  \let\tabu@savecounters \relax
+   \hbadness \@M    \let\hbadness \@tempcnta
+   \hfuzz \maxdimen \let\hfuzz \@tempdima
    \let\tabu@rewrite@X \tabu@rewrite@Xnested
-   \def\tabudefaulttarget{\linewidth}%
-   \def\@elt##1{\global\value{##1}\the\value{##1}\relax}%
-   \xdef\tabu@global@X {\cl@@ckpt}\let\@elt \relax
-   \hbadness\@M \hfuzz\maxdimen
-   \let\hbadness \@tempcnta
-   \let\hfuzz \@tempdima
-   \let\write \tabu@nowrite
-   \let\@footnotetext\@gobble
-   \long\def\@xfootnote[##1]##2{}%
-   \let\tabu@saveX \@gobble
+   \let\savetabu \@gobble        \let\tabudefaulttarget \linewidth
+   \let\write \tabu@nowrite      \let\GenericError  \tabu@GenericError
+   \long\def\@xfootnote[##1]##2{}\let\@footnotetext \@gobble
+   \ifx\@arrayright\relax \let\@arrayright \@empty\fi
    \tabu@TRIAL@hook
 }% \tabu@setup@TRIAL
+\def\tabu@savecounters{%
+   \def\@elt##1{\global\value{##1}\the\value{##1}\relax}%
+   \edef\tabu@global@X {\cl@@ckpt}\let\@elt \relax
+}% \tabu@savecounters
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -2471,31 +2830,75 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %
 %    \begin{macrocode}
-\let\tabu@TRIAL@hook\@empty
-\newcommand\tabuDisableCommands[1]{\g@addto@macro\tabu@TRIAL@hook{#1}}
+\let\tabu@TRIAL@hook \@empty
+\newcommand\tabuDisableCommands[1]{\g@addto@macro\tabu@TRIAL@hook {#1}}
 %    \end{macrocode}
 %    \end{macro}
 %
+%
+% \subsection{One trial after another}
+%
 %    \begin{macro}{\tabu@arrayleft@measure}
 %
 %    Measuring the whole tabular occurs just before \cs{@arrayleft}.
 %    Hence the name of the macro: \cs{tabu@arrayleft@measure}.
 %
+%    \begin{macro}{\tabu@TRIAL}
+%
+%    \cs{halign} is temporarily expanded inside a \cs{vbox} which is captured in \cs{tabu@box}.
+%
 %    \begin{macrocode}
 \def\tabu@arrayleft@measure#1\bgroup{%
-  \def\tabu@Xfinish{\ifnum0=`{\fi\iffalse}\fi\endgroup\tabu@global@X #1\bgroup}%
-  \toks@{%
-      \tabu@setup@everycr
-      \let\@preamble\tabu@savedpreamble}% <required for multicolumn>
-  \tabu@collect
+   \def\tabu@Xfinish{%
+      \tabu@global@Xnested \ifnum0=`{}\fi\endgroup
+      \tabu@global@X #1\bgroup}%
+   \def\tabu@TRIAL {\setbox\tabu@box \hbox\bgroup $#1\bgroup
+                                   \the\toks@ \tabu@endTRIAL}%
+   \toks@{\tabu@setup@everycr
+      \let\@preamble \tabu@savedpreamble}% <required for multicolumn>
+   \tabu@collect
 }% \tabu@arrayleft@measure
 %    \end{macrocode}
 %    \end{macro}
+%    \end{macro}
+%
+%    \begin{macro}{\tabu@long@arrayleft@measure}
+%
+%    This is the long version for \textt{longtabu}
+%    \begin{macrocode}
+\long\def\tabu@long@arrayleft@measure #1\LT@bchunk #2\LT@bchunk{%
+   \def\tabu@Xfinish{%
+      \tabu@global@Xnested \ifnum0=`{}\fi\endgroup
+      \tabu@setup@everycr \let\@preamble \tabu@savedpreamble
+      \tabu@global@X #1\LT@bchunk #2\LT@bchunk}%
+  \def\tabu@TRIAL{%
+      \setbox\tabu@box \hbox\bgroup
+      \tabu@setup@everycr \let\@preamble \tabu@savedpreamble
+      \tabu@global@X \LTchunksize\@M
+      #1\LT@bchunk #2\LT@bchunk \the\toks@ \tabu@endTRIAL}%
+  \toks@{}%\let\LT@output\relax
+  \tabu@collect
+}% \tabu@long@arrayleft@measure
+\def\tabu@long@endTRIAL{%
+   \LT@echunk
+   \global\setbox\@ne \hbox{\unhbox\@ne}\kern\wd\@ne
+   \LT@get@widths
+   \egroup        % got \tabu@box
+   \iftabu@spread \tabu@spreadarith % <only once>
+   \else          \tabu@arith
+   \fi
+   \iftabu@measuring \tabu@measuringfalse
+      \expandafter \tabu@TRIAL % <continue trials>
+   \else
+      \expandafter \tabu@Xfinish
+         \the \expandafter\toks@ \tabu@endenvir  % <we are then!>
+   \fi
+}% \tabu@long@endTRIAL
+%    \end{macrocode}
+%    \end{macro}
 %
-% \subsubsection(Collecting the tabu body){Collecting the \textt{tabu} body: required for \texttbf X columns}
 %
 %    \begin{macro}{\tabu@collect}
-%    \begin{macro}{\tabu@collectbody}
 %
 %    The mechanism is the same as \hologo{AmS}-\cs{collect@body} (also defined in \xfile{environ.sty}).
 %    The content of the tabular is captured inside \cs{toks@}, expanded by \cs{tabu@TRIAL}.
@@ -2506,129 +2909,169 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \edef\tabu@stack{\tabu@pushbegins #1\begin\end\expandafter\@gobble\tabu@stack}%
    \ifx\tabu@stack\@empty
       \toks@\expandafter{\the\toks@#1}\def\tabu@endenvir{\end{#2}}%
-      \expandafter\tabu@TRIAL
+      \expandafter \tabu@TRIAL
    \else
       \toks@\expandafter{\the\toks@#1\end{#2}}%
-      \expandafter\tabu@collectbody
+      \expandafter \tabu@collectbody
    \fi
 }% \tabu@collectbody
 \long\def\tabu@pushbegins#1\begin#2{%
       \ifx\end#2\else b\expandafter\tabu@pushbegins\fi}
 %    \end{macrocode}
 %    \end{macro}
-%    \end{macro}
-%
-%
-% \subsection{Measuring the \textt{tabu}}
-%
-% \subsubsection{One trial after another}
 %
 %
-%    \begin{macro}{\tabu@TRIAL}
 %    \begin{macro}{\tabu@endTRIAL}
 %
-%    \cs{halign} is temporarily expanded inside a \cs{vbox} which is captured in \cs{tabu@box}.
-%
 %    At the end of the trial, we call \cs{tabu@arith} to compute the widths. \cs{tabu@arith} exits
 %    leaving \cs{iftabu@measuring} equal to \cs{iftrue}: a further trial is necessary, or equal to
 %    \cs{iffalse}: the target is reached, \cs{tabu@Xfinish} can print the \textt{tabu} in a last
 %    expansion of \cs{halign}.
 %
 %    \begin{macrocode}
-\def\tabu@TRIAL{\setbox\tabu@box \hbox\bgroup $\@arrayleft
-   \if c\tabu@align\vcenter\else\vbox\fi\bgroup \the\toks@
-                                           \tabu@endTRIAL}% constant
 \def\tabu@endTRIAL{%
-   \ifdefined\adl@ncol  % <arydshln in trials>
-      \csname crcr\endcsname
-      \noalign{\global\adl@ncol\tabu@nbcols}\fi
+   \tabu@adl@endTRIAL   % <arydshln in nested trials>
    \endarray$\egroup
-   \iftabu@spread \tabu@spreadfalse
-      \let\@startpbox \tabu@startpboxORI
-      \tabu@spreadarith % <only once>
-   \else \tabu@arith
+   \iftabu@spread \tabu@spreadarith % <only once>
+   \else          \tabu@arith
    \fi
    \iftabu@measuring \tabu@measuringfalse
-         \expandafter \tabu@TRIAL % <continue trials>
+      \expandafter \tabu@TRIAL % <continue trials>
    \else
-         \toks@\expandafter\expandafter\expandafter{%
-               \the\expandafter\toks@ \tabu@endenvir}%
-         \expandafter \tabu@Xfinish \the\toks@ % <we are then!>
+      \expandafter \tabu@Xfinish
+         \the \expandafter\toks@ \tabu@endenvir  % <we are then!>
    \fi
 }% \tabu@endTRIAL
+\def\tabu@adl@endTRIAL{\crcr \noalign{\global\adl@ncol \tabu@nbcols}}
 %    \end{macrocode}
 %    \end{macro}
-%    \end{macro}
 %
-% \subsubsection{The arithmetic of \textt X columns}
+%
+%
+% \subsection{Algorithms: Measuring the \textt{tabu}}
+%
+% \subsubsection(Algorithm for tabu to){The arithmetic of \textt X columns}
 %
 %    \begin{macro}{\tabu@arith}
-%    \begin{macro}{\tabu@spreadarith}
 %
-%    Algorithms.
+%    General algorithms for \textt{tabu to} with \textt X columns.
 %
 %    \begin{macrocode}
 \def\tabu@arith{%
-   \advance\tabu@cnt \@ne
-%%   \showbox\tabu@box
-   \ifdim \tabu@lasttry=\wd\tabu@box
-      \tabu@message{\tabu@header Reached minimum width. Backing up}%
-   \else
-      \edef\tabu@lasttry{\the\wd\tabu@box}%
-      \tabu@message{\tabu@message@arith}%
-      \ifdim \dimexpr \wd \tabu@box - \tabu@target <\tabu@hfuzz
-         \tabu@message{\tabu@message@reached}%
-         \xdef\tabu@global@X {\tabu@target\the\tabu@target\relax \tabu@global@X
-                              \tabucolX \the\tabucolX\relax}%
-      \else
-         \advance\tabucolX-\dimexpr(\wd\tabu@box-\tabu@target-\tabu@X@sum/65536)
-                              *65536/\tabu@X@sum\relax
+   \advance\tabu@cnt \@ne \tabu@message{\tabu@message@arith}%
+   \ifx \@startpbox\tabu@measure@startpbox
+            \let\@startpbox \tabu@startpboxORI \fi
+   \dimen@ \tabu@X@sum
+   \iftabu@negcoef \tabu@arith@negcoef \fi
+   \ifcase 0\ifdim \dimexpr\wd\tabu@box-\tabu@hfuzz-1sp<\tabu@target
+            \else \ifdim \tabu@lasttry=\wd\tabu@box 1\else
+            2\fi\fi\relax
+      \ifdim \tabu@X@sum=\dimen@ \tabu@message{\tabu@message@reached}%
+      \else\ifdim\tabu@X@sum=\z@ \tabu@message{\tabu@message@reached}%
+      \else\ifnum \tabu@cnt>\@ne \tabu@message{\tabu@message@reached}%
+      \else \tabu@measuringtrue
+            \tabucolX = \dimexpr\tabucolX*\p@/\tabu@X@sum\relax
+      \fi\fi\fi
+   \or \tabu@message{\tabu@header Reached minimum width. Backing up}%
+       \tabu@warn{tabu width = \the\wd\tabu@box\space>
+                  \the\tabu@target\space+ \tabu@hfuzz}%
+   \or
+      \ifdim \tabu@X@sum=\z@ \tabu@measuringtrue \tabucolX=\@tempdima
+      \else \tabu@message{\tabu@message@arith}%
+         \advance\tabucolX-\dimexpr(\wd\tabu@box-\tabu@target-\tabu@X@sum/\p@)
+                                                      *\p@/\tabu@X@sum\relax
          \ifdim \tabucolX<\z@
-            {\let\write\tabu@write\PackageWarning{tabu}
-               {X Columns too narrow (table too wide)\MessageBreak}}%
-               \tabucolX=1em%
+            \tabu@warn{X Columns too narrow (table too wide)}%
+            \tabucolX=\tabucolX@error
          \else \tabu@measuringtrue
+            \ifdim \tabu@X@sum=\dimen@
+               \edef\tabu@lasttry{\the\wd\tabu@box}%
+            \else
+               \ifnum \tabu@cnt>\@ne \edef\tabu@lasttry{\the\wd\tabu@box}\fi
+               \ifdim \tabucolX<\@tempdima \tabucolX \@tempdima\fi
+            \fi
          \fi
       \fi
+   \fi %(ifcase)
+   \iftabu@measuring
+   \else \edef\tabu@global@X{\tabu@global@X
+            \tabucolX    \the\tabucolX\relax
+            \tabu@target \the\tabu@target\relax % < for \savetabu >
+            \ifnum \tabu@nested=\z@
+            \ifx \@arrayright\@empty
+            \ifdim \tabu@X@sum>\z@
+               \def\noexpand\@halignto{to\the\tabu@target}\fi\fi\fi}%
    \fi
+   \tabu@X@sum \dimen@
 }% \tabu@arith
+\def\tabu@arith@negcoef{%
+   \tabu@X@cols \@ne \count@ \tabu@X@cols
+   \@whilesw \ifcsname tabu@X\the\tabu@X@cols\endcsname\fi{%
+      \ifdim \tabu@wd\tabu@X@cols>\p@
+         \expandafter\let\expandafter\tabu@temp 
+                   \csname tabu@X\the\tabu@X@cols\endcsname
+         \ifdim \tabu@wd\tabu@X@cols <\tabu@temp\tabucolX
+            \advance\tabu@X@sum -\tabu@temp\p@
+            \tabu@message{\tabu@message@negcoef{\the\tabu@X@cols}}%
+            \ifdim \tabu@wd\tabu@X@cols >\tabu@wd\count@ \count@ \tabu@X@cols \fi
+      \fi\fi
+      \advance\tabu@X@cols \@ne
+   }%
+   \@tempdima=\dimexpr\tabu@wd\count@ * \p@/
+                     \dimexpr\csname tabu@X\the\count@\endcsname\p@\relax\relax
+}% \tabu@arith@negcoef
+%    \end{macrocode}
+%    \end{macro}
+%
+% \subsubsection(Algorithm for tabu spread){The arithmetic of \textt X columns for \textt{tabu spread}}
+%
+%    \begin{macro}{\tabu@spreadarith}
+%
+%    Algorithm for \textt{tabu spread} with \textt X columns: only the first pass.
+%
+%    \begin{macrocode}
 \def\tabu@spreadarith{%
    \tabu@naturalX \tabu@naturalX@max\relax
    \tabucolX \tabu@naturalX@min\relax
    \tabu@message{\tabu@message@spread}%
    \ifdim \dimexpr \wd\tabu@box + \tabu@spreadtarget <\tabu@target
-      \advance\tabu@spreadtarget \dimexpr\wd\tabu@box-\tabu@naturalX+\tabucolX\relax
+      \advance\tabu@spreadtarget 
+               \dimexpr\wd\tabu@box-\tabu@naturalX+\tabucolX\relax
       \ifdim \tabu@spreadtarget <\tabu@target
-         \tabu@target = \tabu@spreadtarget
+         \tabu@target =\tabu@spreadtarget
       \fi
-      \tabu@message{\expandafter\tabu@msg@align \the\tabu@target {}{}{}{}{}\@@}%
+      \tabu@message{\the\tabu@target}%
       \tabu@message{\ifdim \tabu@spreadtarget>\tabu@target
-                           (tabu) default target used.\fi}%
+                           (tabu) spread reduced to fit default target.\fi}%
    \else
       \tabu@message{\expandafter\tabu@msg@align \the\tabu@target { }{}{}{}{}\@@}
       \tabu@message{(tabu)\ifdim\wd\tabu@box<\tabu@target spread too large\else
                                                  tabu spread is useless here\fi,
                     default target used.}%
    \fi
+   \let\@startpbox \tabu@startpboxORI
    \xdef\tabu@halignto {to\the\tabu@target}%
    \tabucolX \tabu@target
-   \tabu@measuringtrue
+   \tabu@spreadfalse \tabu@measuringtrue
 }% \tabu@spreadarith
 %    \end{macrocode}
 %    \end{macro}
-%    \end{macro}
 %
 % \subsubsection(\xext{log} report){Reporting in the \xext{log} file (\textt{debugshow option})}
 %
 %    \begin{macro}{\tabu@message@arith}
+%    \begin{macro}{\tabu@message@spread}
+%    \begin{macro}{\tabu@message@negcoef}
 %    \begin{macrocode}
 \def\tabu@message@arith{\tabu@header
    \expandafter\tabu@msg@align \the\tabucolX { }{ }{ }{ }{}\@@
    \expandafter\tabu@msg@align \the\wd\tabu@box { }{ }{ }{ }{}\@@
    \expandafter\tabu@msg@align \the\tabu@target { }{ }{ }{ }{}\@@
    \expandafter\tabu@msg@align \the\tabu@X@sum {}{}{}{}{}\@@
+   \ifx\@startpbox\tabu@measure@startpbox\tabu@spaces (coefs<0)\else
+   \ifdim\tabu@X@sum>\z@
    \expandafter\tabu@msg@align \the\dimexpr(\tabu@target-\wd\tabu@box)
-                                      *65536/\tabu@X@sum\relax {}{}{}{}{}\@@}
+                                 *\p@/\tabu@X@sum\relax {}{}{}{}{}\@@\fi\fi}%
 \def\tabu@message@spread{\tabu@spreadheader
    \expandafter\tabu@msg@align \the\tabu@spreadtarget {}{}{}{}{}\@@
    \expandafter\tabu@msg@align \the\wd\tabu@box {}{}{}{}{}\@@
@@ -2636,156 +3079,149 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \expandafter\tabu@msg@align \expandafter-\the\tabu@naturalX {}{}{}{}{}\@@}
 \def\tabu@message@reached{\tabu@header
    \expandafter\tabu@msg@align \the\tabucolX { }{ }{ }{ }{}\@@
-   ******** Reached Target : hfuzz=\tabu@hfuzz\space ********^^J}
+   \expandafter\tabu@msg@align \the\wd\tabu@box {}{}{}{}{}\@@
+  <\expandafter\tabu@msg@align \the\tabu@target { }{ }{ }{ }{}\@@
+  + \tabu@hfuzz\space= hfuzz *****^^J%
+  (tabu)\tabu@spaces******* Reached Target:
+         hfuzz = \tabu@hfuzz\on@line\space *******^^J
+         \ifnum\tabu@nested=\z@^^J\fi}%
+\def\tabu@message@negcoef #1{\tabu@spaces\tabu@spaces
+   * #1. X[-\csname tabu@X#1\endcsname]: natural width
+   = \tabu@wd{#1}
+   < \csname tabu@X#1\endcsname X
+   = \the\dimexpr\csname tabu@X#1\endcsname\tabucolX
+}% \tabu@message@negcoef
+\edef\tabu@spaces{\@spaces}
 \def\do#1{%
    \def\tabu@msg@align##1.##2##3##4##5##6##7##8##9\@@{%
-   \ifnum##1<10 #1#1#1\else
-   \ifnum##1<100 #1#1\else
+   \ifnum##1<10 #1 #1\else
+   \ifnum##1<100 #1 \else
    \ifnum##1<\@m #1\fi\fi\fi
    ##1.##2##3##4##5##6##7##8#1}%
-   \def\tabu@header{%
-      \ifnum\tabu@cnt=\@ne (tabu)
-       Try#1#1#1#1tabu X#1#1#1#1#1#1tabu Width#1#1#1#1#1Target%
-                  #1#1#1#1#1#1#1#1#1Coefs#1#1#1#1#1#1#1Update^^J\fi
-       (tabu) \ifnum\tabu@cnt<10 #1\fi\the\tabu@cnt)#1#1}%
+   \def\tabu@header{(tabu) \ifnum\tabu@cnt<10 #1\fi\the\tabu@cnt) #1}%
+   \def\tabu@titles{\ifnum \tabu@nested=\z@
+      (tabu) Try#1 #1 tabu X #1 #1 #1tabu Width #1 #1 Target
+                  #1 #1 #1 #1 Coefs #1 #1 #1 Update^^J\fi}%
    \def\tabu@spreadheader{%
-      (tabu) Try#1#1#1#1Spread#1#1#1tabu Width#1#1#1#1#1Min Nat.#1#1#1#1Nat.X%
-                                              #1#1#1#1#1#1#1#1#1New Target^^J%
+      (tabu) Try#1 #1 Spread #1 #1 tabu Width #1 #1 Nat. Min. #1 #1 #1 Nat.X
+                                                      #1 #1 #1 New Target^^J%
       (tabu)spread}%
+   \def\tabu@tracing@save##1{\begingroup
+      \def\col@sep ####1\relax       {(tabu) column sep #1 #1 #1 = ####1^^J}%
+      \def\arrayrulewidth ####1\relax{(tabu) arrayrulewidth #1 = ####1^^J}%
+      \def\doublerulesep ####1\relax {(tabu) doublerulesep #1 #1= ####1^^J}%
+      \def\extrarowheight ####1\relax{(tabu) extrarowheight #1 = ####1^^J}%
+      \def\extratabsurround ####1\relax{(tabu) extratabsurround = ####1^^J}%
+      \def\minrowclearance ####1\relax {(tabu) minrowclearance#1 = ####1^^J}%
+      \def\arraystretch ####1{(tabu) arraystretch #1 #1 = ####1^^J}%
+      \def\NC@find ####1\@nil{(tabu) tabu preamble#1 #1 = \detokenize{####1}^^J}%
+      \def\tabu@wddef####1####2{(tabu) Natural width ####1 = ####2^^J}%
+      \let\edef \@gobbletwo \let\def \@empty
+      \tabu@message{%
+         (tabu) \string\savetabu{##1}: \on@line^^J%
+      \ifx \savetabu\tabusaveX
+         (tabu) X columns width #1 = \the\tabucolX^^J\fi
+         (tabu) target #1 #1 #1 #1 #1 = \the\tabu@target^^J%
+         \tabu@savedparam
+         \tabu@savedpream \@nil
+         \iftabu@negcoef \tabu@savewd\fi}%
+      \endgroup}%
 }\do{ }
 %    \end{macrocode}
 %    \end{macro}
-%
-% \subsubsection(Natural width measure){Measuring the natural width for \textt{tabu spread}}
-%
-%    \begin{macro}{\tabu@spread@startpbox}
-%    \begin{macro}{\tabu@spread@endhbox}
-%
-%    When ``\textt{tabu spread}'' is used with \textt X columns, the first trial must
-%    measure the natural width of the columns. Therefore, the \cs{vbox}, \cs{vtop} or \cs{vcenter}
-%    corresponding to the \textt X columns definitions are temporarily changed into \cs{hbox}. More
-%    precisely, the natural width is measured with \cs{vbox}\M*{\cs{hbox}\M*{...}}.
-%
-%    For the furthur trials, the standard scheme for \textt X column is used.
-%
-%    \begin{macrocode}
-\def\tabu@spread@startpbox#1{\bgroup
-   \in@{\tabucolX}{#1}%
-   \ifin@
-      \hbox to\tabu@target\bgroup\aftergroup\tabu@spread@endhbox
-         \tabu@spread@startpbox@setup \hfil
-   \else
-      \expandafter\@gobble\tabu@startpboxORI{#1}% \@gobble \bgroup
-   \fi
-}% \tabu@spread@startpbox
-\def\tabu@spread@startpbox@setup{%
-   \let\tabu@vskipORI\vskip \let\tabu@adl@draw\adl@draw
-   \def\adl@draw{\let\vskip\tabu@vskipORI\tabu@adl@draw}%
-   \let\vss\relax\let\vfil\vss\let\vfill\vss\let\vskip\@tempskipa
-}% \tabu@spread@startpbox@setup
-\def\tabu@spread@endhbox{%
-   \ifnum\badness>\@M %<text does not fit>
-      \global\tabu@naturalX \tabu@target
-   \else
-      \setbox\tabu@box\lastbox
-      \setbox\tabu@box\hbox{\unhbox\tabu@box}%
-      \global\advance\tabu@X@cols \@ne
-      \ifcsname tabu@X\the\tabu@X@cols\endcsname
-         \global\advance\tabu@naturalX \wd\tabu@box
-      \else
-         \global\tabu@X@cols \@ne
-         \global\tabu@naturalX \wd\tabu@box
-      \fi
-      \ifdim \tabu@naturalX@max<\tabu@naturalX
-         \xdef\tabu@naturalX@max{\the\tabu@naturalX}%
-      \fi
-      \ifdim \tabu@naturalX@min<\dimexpr \wd\tabu@box * \tabu@X@sum /
-                  (65536*\csname tabu@X\the\tabu@X@cols\endcsname)\relax
-         \xdef\tabu@naturalX@min{\the\dimexpr \wd\tabu@box * \tabu@X@sum /
-                     (65536*\csname tabu@X\the\tabu@X@cols\endcsname)\relax}%
-      \fi
-   \fi
-   \box\tabu@box
-   \egroup % end of \vtop (measure)
-}% \tabu@spread@endhbox
-%    \end{macrocode}
 %    \end{macro}
 %    \end{macro}
 %
-% \subsection(Lines inside tabu){Lines inside \textt{tabu}}
 %
-% \subsubsection{Vertical lines}
+% \subsubsection(Natural width measure){Measuring the natural width for \textt{tabu spread} and negativ width-coefficients}
 %
+%    \begin{macro}{\tabu@measure@startpbox}
+%    \begin{macro}{\tabu@measure@endpbox}
 %
-%    \begin{macro}{\tabuvline@rewrite}
+%    When ``\textt{tabu spread}'' is used with \textt X columns, the first trial must
+%    measure the natural width of the columns. When \textt X columns have negativ coefficient,
+%    the natural is computed after the target has been reached, with the absolute coefficients.
 %
-%    \textt\textbar\ is defined as a new column type (only inside \textt{tabu}) in order to add an optional argument:
-%    the width of the rule.
+%    Nested trials may occur (\textt{tabu spread} inside a \textt X column with negativ
+%    coefficient for example).
 %
-%    \begin{macrocode}
-\newcommand*\tabuvline@rewrite[1][]{\tabuvline@arg{#1}%
-                     \expandafter \NC@find \tabu@temp}
-\def\tabu@vline#1{\vrule width#1}
-%    \end{macrocode}
-%    \end{macro}
+%    For the furthur trials, the standard scheme for \textt X column is used: the natural width
+%    is measured only once.
 %
-%    \begin{macro}{\tabuvline@arg}
+%    \hologo{pdfTeX} font expansion is disabled inside the \textt{varwidth} environment
+%    (we set \cs{pdfadjustspacing} to \textt 0).
 %
-%    A tedious (and fastidious) macro to parse the optional argument of \textt\textbar\ vertical lines...
-
 %    \begin{macrocode}
-\def\tabuvline@arg#1{%
-   \ifx\\#1\\%    <shortcut when no option>
-      \edef\tabu@temp{!{%
-         \iftabu@colortbl\begingroup\noexpand\CT@arc@\fi
-         \noexpand\tabu@vline\arrayrulewidth
-         \iftabu@colortbl\endgroup\fi}}%
-   \else \futurelet \tabu@temp \tabuvline@argi #1\p@\p@\@nnil \tabuvline@argiii
+\def\tabu@measure@startpbox#1{\bgroup
+   \let\@startpbox \tabu@startpboxORI           % in case of nesting
+   \in@{\tabu@dimexpr}{#1}%
+   \ifin@ 
+      \global\advance\tabu@X@cols \@ne
+      \ifcsname tabu@X\the\tabu@X@cols\endcsname\else
+         \global\tabu@X@cols \@ne
+         \global\tabu@naturalX \z@
+      \fi
    \fi
-}% \tabuvline@arg
-\def\tabuvline@argi{%
-   \let\tabu@color \@empty
-   \ifcat A\noexpand\tabu@temp
-         \@tempdima\arrayrulewidth
-         \expandafter\tabu@getlinecolor
-   \else \expandafter\tabuvline@argii
+   \iftabu@spread\else
+      \ifin@ {\let\tabu@dimexpr \@firstoftwo\expandafter}%
+             \ifdim \tabu@wd{#1}<\p@ \in@false\fi\fi\fi
+   \ifin@
+      \begingroup \let\tabu@dimexpr \@secondoftwo
+         \edef\x{\endgroup \def\noexpand\tabu@temp{\the\dimexpr#1}%
+      }\x
+      \setbox\tabu@box=\hbox\bgroup
+         \let\tabu@rewrite@X \tabu@@rewrite@X
+         \begin{varwidth}{\tabu@temp}\narrowragged\arraybackslash
+            \tabu@noadjustspacing \parfillskip\@flushglue
+               \bgroup \aftergroup\tabu@measure@endpbox
+   \else
+      \expandafter\@gobble\@startpbox{#1}% \@gobble \bgroup
    \fi
-}% \tabuvline@argi
-\def\tabuvline@argii#1\@nnil{%
-   \tabu@maybecolor \@tempdima #1 \@nnil
-}% \tabuvline@argii
-\def\tabuvline@argiii{%
-   \edef\tabu@temp{!{\begingroup
-      \ifx\tabu@color\@empty
-      \iftabu@colortbl \noexpand\CT@arc@ \fi
-      \else \tabu@color\fi
-      \noexpand\tabu@vline{\the\@tempdima}\endgroup}}%
-}% \tabuvline@argiii
+}% \tabu@measure@startpbox
+\ifdefined\pdfadjustspacing
+   \def\tabu@noadjustspacing{\pdfadjustspacing\z@}%
+\else
+   \let\tabu@noadjustspacing\relax
+\fi
+\def\tabu@measure@endpbox{%
+   \@finalstrut\@arstrutbox\end{varwidth}\egroup      % <got my \tabu@box>
+   \global\advance\tabu@naturalX \wd\tabu@box
+   \ifdim \tabu@naturalX@max<\tabu@naturalX
+      \xdef\tabu@naturalX@max{\the\tabu@naturalX}\fi
+   \@tempdima=\dimexpr \wd\tabu@box * \tabu@X@sum /
+         \dimexpr\csname tabu@X\the\tabu@X@cols\endcsname\p@\relax\relax
+   \ifdim \tabu@naturalX@min<\@tempdima
+      \xdef\tabu@naturalX@min{\the\@tempdima}\fi
+   \ifdim \tabu@wd\tabu@X@cols>\z@
+   \ifdim \tabu@wd\tabu@X@cols<\wd\tabu@box
+      \tabu@wddef\tabu@X@cols {\the\wd\tabu@box}%
+      \tabu@debug{\tabu@spaces\tabu@spaces
+         * \the\tabu@X@cols. X[-\csname tabu@X\the\tabu@X@cols\endcsname]:
+         target=\the\dimexpr\tabu@temp\relax\space
+         \expandafter\expandafter\expandafter\string\tabu@wd\tabu@X@cols
+         =\tabu@wd\tabu@X@cols}%
+   \fi\fi
+   \box\tabu@box \egroup % end of \vtop (measure)
+}% \tabu@measure@endpbox
+\def\tabu@wd#1{\csname tabu@W\the\tabu@nested @\number#1\endcsname}
+\def\tabu@wddef#1{\expandafter\xdef
+               \csname tabu@W\the\tabu@nested @\number#1\endcsname}
+\def\tabu@wdlet#1{\global\expandafter\let
+               \csname tabu@W\the\tabu@nested @\number#1\endcsname}
+\def\tabu@naturalX@min{\z@}
+\def\tabu@naturalX@max{\z@}
 %    \end{macrocode}
 %    \end{macro}
-%
-%
-%    \begin{macro}{\tabu@lines}
-%
-%  This macro is used in \cs{tabu@setup} to ``mount'' the character \textt\textbar\ as a column type.
-%
-%    \begin{macrocode}
-{
-\expandafter\let\csname NC@find@|\endcsname\relax
-\expandafter\let\csname NC@rewrite@|\endcsname\relax
-\xdef\tabu@lines{%
-   \let\csname NC@find@|\endcsname \noexpand\tabuvlines@find
-   \let\csname NC@rewrite@|\endcsname \noexpand\tabuvline@rewrite
-}% \tabu@vline
-}
-\def\tabuvlines@find#1|{\NC@{#1}}
-%    \end{macrocode}
 %    \end{macro}
 %
 %
-% \subsubsection{Horizontal lines: \cs{tabucline}}
+% \subsection{\cs{everycr} setup and \cs{tabuphantomline}}
 %
 %    \begin{macro}{\tabu@setup@everycr}
+%
+%    \cs{ialign} resets \cs{everycr} to an empty token. This macro sets \cs{everycr} for the
+%    \textt{tabu} environment.
+%
 %    \begin{macrocode}
 \def\tabu@setup@everycr{%
    \tabu@firstclinetrue
@@ -2820,7 +3256,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
       \global\minrowclearance \z@
    \fi
    \global\let\vcenter \vbox
-   \iftabu@nested\vspace*{\dimexpr\extrarowheight-\ht\@arstrutbox}\fi
+   \ifnum \tabu@nested>\z@ \vspace*{\dimexpr\extrarowheight-\ht\@arstrutbox}\fi
    \toks@{}\count@\@ne
    \@whilenum\count@<\tabu@nbcols\do{\advance\count@\@ne
                         \toks@\expandafter{\the\toks@&}}%
@@ -2836,6 +3272,77 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \end{macrocode}
 %    \end{macro}
 %
+%
+%
+% \subsection(Lines inside tabu){Lines inside \textt{tabu}}
+%
+% \subsubsection{Vertical lines}
+%
+%
+%    \begin{macro}{\tabuvline@rewrite}
+%
+%    \textt\textbar\ is defined as a new column type but only inside the group
+%    where \cs{@mkpream} does its job. This way, the modification is very local
+%    to \textt{tabu}.
+%
+%    \begin{macro}{\tabu@lines}
+%
+%    This feature is disabled with the \textt{light} option.
+%
+%    \begin{macrocode}
+\def\tabu@lines{{\endlinechar\m@ne \scantokens{\def\x{|}}%
+   \expandafter}\expandafter\tabu@lines@ \x
+}% \tabu@lines
+\def\tabu@lines@#1{%
+   \tabu@newcolumntype #1{\tabuvline@rewrite}%
+   \NC@list\expandafter{\the\NC@list \NC@do #1}%
+}% \tabu@lines@
+\newcommand*\tabuvline@rewrite[1][]{\tabuvline@arg{#1}%
+                     \expandafter \NC@find \tabu@temp}
+\def\tabu@vline#1{\vrule width#1}
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+%
+%    \begin{macro}{\tabuvline@arg}
+%
+%    A tedious (and fastidious) macro to parse the optional argument of \textt\textbar\ vertical lines...
+
+%    \begin{macrocode}
+\def\tabuvline@arg#1{%
+   \ifx\\#1\\%    <shortcut when no option>
+      \edef\tabu@temp{!{%
+         \iftabu@colortbl\begingroup\noexpand\CT@arc@\fi
+         \noexpand\tabu@vline\arrayrulewidth
+         \iftabu@colortbl\endgroup\fi}}%
+   \else \futurelet \tabu@temp \tabuvline@argi #1\p@\p@\@nnil \tabuvline@argiii
+   \fi
+}% \tabuvline@arg
+\def\tabuvline@argi{%
+   \let\tabu@color \@empty
+   \ifcat A\noexpand\tabu@temp
+         \@tempdima\arrayrulewidth
+         \expandafter\tabu@getlinecolor
+   \else \expandafter\tabuvline@argii
+   \fi
+}% \tabuvline@argi
+\def\tabuvline@argii#1\@nnil{%
+   \tabu@maybecolor \@tempdima #1 \@nnil
+}% \tabuvline@argii
+\def\tabuvline@argiii{%
+   \edef\tabu@temp{!{\begingroup
+      \ifx\tabu@color\@empty
+      \iftabu@colortbl \noexpand\CT@arc@ \fi
+      \else \tabu@color\fi
+      \noexpand\tabu@vline{\the\@tempdima}\endgroup}}%
+}% \tabuvline@argiii
+%    \end{macrocode}
+%    \end{macro}
+%
+%
+% \subsubsection{Horizontal lines: \cs{tabucline}}
+%
 %    \begin{macro}{\tabucline}
 %
 %     \cs{tabucline}\M[style or spec.]\M*{start-end}
@@ -2847,15 +3354,15 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \begin{macrocode}
 \def\tabu@linedash{4pt}%   <default value>
 \def\tabu@dashgap{4pt}%    <default value>
-\def\tabucline{\noalign{\ifnum0=`}\fi\@ifstar
+\def\tabucline{\noalign{\ifnum0=`}\fi \@ifstar
    {\@tempswatrue\tabu@cline}
    {\@tempswafalse\tabu@cline}}%
-\newcommand*\tabu@cline[2][]{%
+\newcommand*\tabu@cline[2][]{\toks@{}%
    \tabu@startstop{#2}\tabu@getlinespec{#1}\@multicnt\@ne
-   \ifnum\tabu@start>\tabu@stop \the\toks@
-   \else\ifx\tabu@xleaders\relax\the\toks@
+   \ifnum\tabu@start>\tabu@stop
+   \else\ifx\tabu@xleaders\relax
    \else
-      \toks@{\ifnum0=`{\fi}\noalign{\global\let\@arstrutbox \voidb@x}}%
+      \toks@{\noalign{\global\let\@arstrutbox \voidb@x}}%
 %%      \iftabu@firstcline\if\tabu@align t\vskip-\ht\@arstrutbox\fi\fi
       \@whilenum\@multicnt<\tabu@start\do{\advance\@multicnt\@ne
                               \toks@\expandafter{\the\toks@ &}}%
@@ -2865,11 +3372,11 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
          \expandafter \tabu@add \csname tabu@tok@\the\@multicnt L\endcsname \@nil
          \fi
          \ifcase 0\if@tempswa\else\ifnum \@multicnt<\tabu@stop 1\fi\fi\relax
-            \toks@\expandafter{\the\toks@ \color@begingroup}%
-            \toks@\expandafter\expandafter\expandafter{\expandafter\the
-                              \expandafter\toks@ \tabu@xleaders \color@endgroup}%
+            \toks@\expandafter{\the\toks@ \begingroup}%
+            \toks@\expandafter{\the\expandafter\toks@
+                               \tabu@xleaders \endgroup}%
          \fi
-         \ifcase 0\if@tempswa\else\ifnum \@multicnt<\tabu@stop 1\fi\fi %
+         \ifcase 0\if@tempswa\else\ifnum \@multicnt<\tabu@stop 1\fi\fi\relax
          \expandafter \tabu@add \csname tabu@tok@\the\@multicnt R\endcsname \@nil
          \fi
          \ifnum\@multicnt<\tabu@stop
@@ -2879,13 +3386,14 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
       \repeat
       \@whilenum\@multicnt<\tabu@nbcols\do{\advance\@multicnt\@ne
                               \toks@\expandafter{\the\toks@ &}}%
-      \toks@\expandafter{\the\toks@ \cr \noalign{%
-                     \global\let\@arstrutbox \tabu@arstrutbox}}%
-%%      \message{LIGNE AJOUTEE:\the\toks@}%
-      \the\toks@
+      \toks@\expandafter{\the\toks@ \cr
+            \noalign{\global\let\@arstrutbox \tabu@arstrutbox}}%
+%%      \tabu@debug{LIGNE AJOUTEE:\the\toks@}%
    \fi\fi
-}% \tabucline
-\def\tabu@add #1\@nil{\toks@\expandafter{\the\toks@ #1\ifmmode$\fi}}
+   \ifnum0=`{\fi\expandafter}\the\toks@
+}% \tabu@cline
+\def\tabu@add #1\@nil{\toks@\expandafter{\the\toks@
+              \begingroup #1\endgroup\ifmmode$\fi}}
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -2925,7 +3433,8 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \else \tabu@getline{#1\p@ on0pt off0pt}\fi\fi\fi\fi\fi
 }% \tabu@getlinespec
 \def\tabu@defleaders#1{%
-   \def\tabu@xleaders{\xleaders\hbox{\lower.5\extrarowheight#1}\tabu@leaderfill}}
+   \def\tabu@xleaders{\iftabu@colortbl\CT@arc@\fi
+      \xleaders\hbox{\lower.5\extrarowheight#1}\tabu@leaderfill}}
 \def\tabucline@warn#1{\PackageWarning{tabu}
    {Undefined line syle: #1
    \MessageBreak Using default line style instead}%
@@ -2955,13 +3464,16 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
       \tabu@lineoff #1 on#2 off\tabu@dashgap \p@ \@nnil
    \else
       \tabu@maybecolor \@tempdima \arrayrulewidth #1\p@\@nnil
-      \ifx\tabu@color\@empty \tabucline@warn{#4}\else
+      \ifx\tabu@color\@empty \tabucline@warn\@tempa\else
       \@tempdimb \z@
       \tabu@lineoff off0pt \p@\@nnil \fi
    \fi
 }% \tabu@lineon
 \def\tabu@lineoff #1off#2\@nnil{%
    \tabu@maybecolor \@tempdimc #2\p@ \@nnil
+   \iftabu@colortbl \ifx \tabu@color\@empty
+      \def\tabu@color{\noexpand\CT@arc@}%
+   \fi\fi
    \ifdim \@tempdimb=\z@
       \ifdim \@tempdimc>\z@ \@tempdimb \tabu@dashgap\relax\fi\fi
    \ifdim \@tempdimc=\z@
@@ -3030,8 +3542,9 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \endgroup
 }% \tabu@linestyle
 \expandafter\def \csname tabu@line@style@\endcsname {%
-                                     \let\tabu@xleaders \tabu@defaultleaders}%
-\def\tabu@defaultleaders{\leaders
+                                    \let\tabu@xleaders \tabu@defaultleaders}%
+\def\tabu@defaultleaders{\iftabu@colortbl\CT@arc@\fi
+   \leaders
    \iftabu@firstcline
       \vrule  depth \arrayrulewidth
    \else
@@ -3049,9 +3562,11 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    \begin{macro}{\tabu@sanitizetext}
 %    \begin{macrocode}
 {\catcode32=13\relax\catcode`\^^@=13\relax
-\gdef\tabu@verb{\@sanitize\makeatletter\catcode`\^=7\edef\^{\string^}%
-\catcode32=13\let =\ \catcode`\^^@=13\def^^@{\linebreak}\endlinechar\m@ne}%
-}
+\gdef\tabu@verb{\@sanitize\catcode`\^=7\edef\^{\string^}\tabu@makeatletter
+\catcode32=13\let =\ \catcode`\^^@=13\def^^@{\hskip\parfillskip\null\linebreak}%
+\endlinechar\m@ne}}
+{\catcode64=13\edef @{\string @}\expandafter\xdef
+   \csname tabu@makeatletter\endcsname{\catcode64=13\def\noexpand @{\unskip @}}}
 \newcommand\tabu@sanitizetext[1][\ttfamily]{\begingroup
                         \tabu@verb #1\tabu@s@nitizetext}
 \long\def\tabu@s@nitizetext#1{\@makeother\{\@makeother\}%
@@ -3064,12 +3579,15 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % \subsubsection{\cs{tabudecimal}}
 %
 %    \begin{macro}{\tabudecimal}
+%
+%    \cs{tabu@tabudecimal} is \cs{tabudecimal} inside \textt{tabu}.
+%
 %    \begin{macrocode}
 \def\tabu@tabudecimal#1{%
    \def\tabu@decimal{#1}\@temptokena{}%
    \let\tabu@getdecimal@ \tabu@getdecimal@ignorespaces
    \tabu@scandecimal
-}% \tabudecimal
+}% \tabu@tabudecimal
 \def\tabu@scandecimal{\futurelet \tabu@temp \tabu@getdecimal@}
 \def\tabu@skipdecimal#1{#1\tabu@scandecimal}
 \def\tabu@getdecimal@ignorespaces{%
@@ -3088,6 +3606,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \def\tabu@get@decimalspace#1{%
       \@temptokena\expandafter{\the\@temptokena #1}\tabu@scandecimal}%
 }\do{ }
+\let\tabu@@tabudecimal \tabu@tabudecimal
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -3138,37 +3657,78 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %    When this command is called by the user, the \textt{tabu} preamble and target are globally
 %    stored into a macro \cs{tabu@saved@\meta{user-name}}.
 %
-%    \begin{macro}{\tabu@saveX}
-%
-%    \cs{tabu@saveX} replaces \cs{savetabu} inside a \textt{tabu} with \textt X columns.
-%    The \textt X columns widths have to be stored, that is, the value in points of \cs{tabucolX}.
-%
 %    \begin{macrocode}
 \newcommand*\savetabu[1]{\noalign{%
    \ifx\\#1\\\tabu@savewarn{}{The tabu will not be saved}\else
-      \@ifundefined{tabu@save@\string#1}{}{\tabu@savewarn{#1}{Overwritting}}%
-      {\toks@\expandafter{\tabu@saved}%
-      \expandafter\xdef\csname tabu@saved@\string#1\endcsname{%
-         \tabu@target\the\tabu@target\relax
-         \the\toks@}}%
-   \fi}%
-}% \savetabu
-%    \end{macrocode}%
-%
-%    \begin{macrocode}
-\def\tabu@saveX#1{\noalign{%
-   \ifx\\#1\\\tabu@savewarn{}{The tabu will not be saved}\else
       \@ifundefined{tabu@saved@\string#1}{}{\tabu@savewarn{#1}{Overwritting}}%
-      {\toks@\expandafter{\tabu@saved}%
-      \expandafter\xdef\csname tabu@saved@\string#1\endcsname{%
-         \tabucolX\the\tabucolX\relax
-         \tabu@target\the\tabu@target\relax
-         \the\toks@}}%
+      {%
+      \toks0\expandafter{\@preamble}%
+      \toks1\expandafter{\tabu@savedparam}%
+      \toks2\expandafter{\tabu@savedpream}%
+      \iftabu@colortbl
+         \toks3\expandafter{\expandafter\gdef\expandafter\CT@arc@
+            \expandafter{\CT@arc@}}%
+         \toks3\expandafter{\the\toks\expandafter3
+            \expandafter\gdef\expandafter\CT@drsc@\expandafter{\CT@drsc@}}%
+      \else \toks3{}%
+      \fi
+      \iftabu@negcoef
+         \edef\tabu@savewd{\tabu@savewd{\number\numexpr1}}%
+         \toks3\expandafter{\the\toks\expandafter3\tabu@savewd}\fi
+      \expandafter\xdef\csname tabu@saved@\string#1\endcsname##1{%
+         \noexpand\ifcase##1\relax
+            \noexpand\ifdim\tabu@target>\z@
+               \noexpand\tabu@warn@usetabu
+            \noexpand\fi
+            \tabu@target \the\tabu@target\relax
+            \tabucolX \the\tabucolX\relax            
+            \the\toks1%
+            \gdef\noexpand\tabu@usetabu{%
+               \the\toks1%
+               \def\noexpand\@halignto{\@halignto}%
+               \tabucolX \the\tabucolX\relax
+               \def\noexpand\@preamble{\the\toks0}%
+               \noexpand\tabu@make@arstrutbox
+               \the\toks3
+               \noexpand\ifx \noexpand\tabu@align\noexpand\tabu@aligndefault@text
+                  \def\noexpand\tabu@align{\tabu@align}%
+               \noexpand\fi}%
+            \aftergroup\noexpand\tabu@usetabu
+         \noexpand\else
+            \noexpand\ifdim\tabu@target=\z@
+               \tabu@target \the\tabu@target\relax
+            \noexpand\fi
+            \gdef\noexpand\tabu@preamble{%
+               \noexpand\ifx \noexpand\tabu@align\noexpand\tabu@aligndefault@text
+                  \def\noexpand\tabu@align{\tabu@align}%
+               \noexpand\fi}%
+            \aftergroup\noexpand\tabu@preamble
+         \noexpand\fi
+         \the\toks2}%
+      \tabu@message@save{#1}}%
    \fi}%
-}% \tabu@saveX
+}% \savetabu
+\def\tabu@aligndefault@text{\tabu@aligndefault}%
+\def\tabu@warn@usetabu{\PackageWarning{tabu}
+   {Specifying a target with \string\usetabu\space is useless
+   \MessageBreak The target cannot be changed!}}
+\def\tabu@savewd#1{%
+   \ifnum#1>\tabu@nbcols \expandafter \@gobble
+   \else \ifdim\tabu@wd{#1}>\z@
+         \noexpand\tabu@wddef{#1}{\tabu@wd{#1}}\fi
+         \expandafter\tabu@savewd % loop
+   \fi{#1+1}%
+}% \tabu@savewd
+\def\tabu@make@arstrutbox{%
+  \@tempdima \ht \strutbox
+  \advance \@tempdima by\extrarowheight
+  \setbox \@arstrutbox \hbox{\vrule
+             \@height \arraystretch \@tempdima
+             \@depth \arraystretch \dp \strutbox
+             \@width \z@}%
+}% \tabu@make@arstrutbox
 %    \end{macrocode}
 %    \end{macro}
-%    \end{macro}
 %
 %    \begin{macro}{\tabu@savewarn}
 %    \begin{macro}{\tabu@saveerr}
@@ -3212,15 +3772,17 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 \def\tabu@rowfont{\noalign{\ifnum0=`}\fi\tabu@row@font}
 \newcommand*\tabu@row@font[2][]{%
    \global\let\tabu@rowfontreset \tabu@rowfont@reset
-   \global\let\tabu@@cellleft \tabu@cellleft
-   \global\let\tabu@@cellright \tabu@cellright
-   \gdef\tabu@cellfont{#2}%
+   \global\let\tabu@@cellleft    \tabu@cellleft
+   \global\let\tabu@@cellright   \tabu@cellright
+   \gdef\tabu@cellfont{\let\color \tabu@colorleavevmode#2\let\color \tabu@colorORI}%
    \ifcsname tabu@cell@#1\endcsname  % row alignment
          \csname tabu@cell@#1\endcsname \fi
    \toks@\expandafter {\tabu@cellleft\tabu@cellfont}% inside \noalign group ok
    \xdef\tabu@cellleft {\the\toks@}%
    \ifnum0=`{\fi}% end of noalign group
 }% \rowfont
+\def\tabu@colorleavevmode{\leavevmode\tabu@colorORI}
+\AtBeginDocument{\let\tabu@colorORI \color}
 %    \end{macrocode}
 %    \end{macro}
 %
@@ -3301,7 +3863,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %
 %    \begin{macrocode}
 \newif\iftabu@cellright
-\AtBeginDocument{\let\array@prepnext@tok \prepnext@tok }% original definition
+\AtBeginDocument{\let\tabu@prepnext@tokORI \prepnext@tok }% original definition
 \def\tabu@prepnext@tok{%
    \ifnum \count@<\z@  % <first initialisation>
       \@tempcnta \@M   % <not initialized by array.sty>
@@ -3319,9 +3881,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
             \tabu@cellrightfalse % <only once>
             \tabu@savetok R\tabu@preptokenright
          \fi
-         \ifnum \tabu@nbcols=\@ne
-            \tabu@savetok L% LEFT token is always empty unless >{...}
-         \fi
+         \ifnum \tabu@nbcols=\@ne \tabu@savetok L\fi
          \tabu@preptokenleft
       \or                     % (case 1) previous token is right
          \tabu@savetok R\tabu@cellrighttrue
@@ -3337,7 +3897,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
          \fi
       \fi % \ifcase
    \fi
-   \array@prepnext@tok
+   \tabu@prepnext@tokORI
 }% \tabu@prepnext@tok
 \def\tabu@preptokenright{%
    \advance \count@ \m@ne
@@ -3351,16 +3911,17 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \expandafter\tabu@savet@k\csname tabu@tok@\the\tabu@nbcols #1\endcsname
 }% \tabu@savetok
 \def\tabu@savet@k#1{%
-   \@temptokena\toks\count@
-   \ifx#1\relax\else \@temptokena\expandafter\expandafter
-                     \expandafter{\expandafter#1\the\@temptokena}%
-   \fi
-   \@temptokena\expandafter{\expandafter\def\expandafter#1\expandafter{%
-                                                      \the\@temptokena}}%
-   \toks@\expandafter\expandafter\expandafter{\expandafter\tabu@global@temp
-                                                      \the\@temptokena}%
-   \xdef\tabu@global@temp{\the\toks@}%
-   \expandafter\endgroup \the\@temptokena
+   \ifnum \@chclass=\@ne \toks@\toks\count@
+   \else\ifnum\@chclass=5 \toks@\toks\count@
+   \else \toks@{}\fi\fi
+   \unless\ifx#1\relax
+      \toks@\expandafter\expandafter\expandafter{%
+                        \expandafter#1\the\toks@}\fi
+   \toks@\expandafter{\expandafter\def\expandafter#1\expandafter{%
+                                                      \the\toks@}}%
+   \@temptokena\expandafter{\tabu@global@temp}%
+   \xdef\tabu@global@temp {\the\@temptokena \the\toks@}%
+   \expandafter\endgroup \the\toks@
 }% \tabu@savetok
 %    \end{macrocode}
 %    \end{macro}
@@ -3648,7 +4209,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 }% \tabu@adl@xarraydashrule
 %    \end{macrocode}
 %
-% \subsubsection{arydshln and empty \textt p columns}
+% \subsubsection{arydshln, colors without \xpackage{colortbl} and empty \textt p columns}
 %
 % \xpackage{arydshln} redefines \cs{@endpbox} for \textt p columns. The definition is stored in \cs{adl@act@endpbox}.
 % Here it is:
@@ -3665,13 +4226,23 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 % However, just like in \xfile{array.sty}, this array-\textt{strut} should be inserted inconditionnally,
 % and \cs{ifhmode} applies only to \cs{nobreak} (misplaced \cs{fi} in \xpackage{arydshln} definition).
 %
+% Finally, \xpackage{arydshln} is not compatible with colors in columns, such that: \textt{>\M*{\cs{color}\M*{red}}p{3in}},
+% Unless \xpackage{colortbl} is also loaded, the color group is missing.
+%
+% Fixed inside \textt{tabu}.
 %
 %    \begin{macrocode}
 \def\tabu@adl@act@endpbox{%
    \unskip \ifhmode \nobreak \fi    \@finalstrut \@arstrutbox
-   \egroup
+   \egroup \egroup
    \adl@colhtdp \box\adl@box \hfil
 }% \tabu@adl@act@endpbox
+\def\tabu@adl@fix{%
+   \let\adl@xarraydashrule \tabu@adl@xarraydashrule % <fix> arydshln
+   \let\adl@act@endpbox    \tabu@adl@act@endpbox    % <fix> arydshln
+   \let\adl@act@@endpbox   \tabu@adl@act@endpbox    % <fix> arydshln
+   \let\@preamerror        \@preamerr               % <fix> arydshln
+}% \tabu@adl@fix
 %    \end{macrocode}
 %
 %
@@ -3687,10 +4258,50 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %  head/left=\moveleft1cm\vbox to0pt{\vss\setbox0=\null\ht0=0pt\wd0=\paperwidth\dp0=\headheight\rlap{\colorbox{GhostWhite}{\box0}}}\vskip-\headheight t\,a\,b\,u\,\ \ i\,n\,d\,e\,x,
 %  }
 %
+% \begin{thebibliography}{9}
+%
+% \bibitem{array}
+%   \textit{A new implementation of \LaTeX's \textt{tabular} and \textt{array} environments} by Frank Mittelbach\\
+%   2008/09/09 v2.4c -- Tabular extension package (FMi) \\
+%   \href{http://www.tex.ac.uk/tex-archive/help/Catalogue/entries/array.html}{\nolinkurl{CTAN:help/Catalogue/entries/array.html}}
+%
+% \bibitem{varwidth}
+% \textit{The \xpackage{varwidth} package} by Donald Arseneau \\
+%   2009/03/30 ver 0.92 -- Variable-width minipages \\
+%   \href{http://www.ctan.org/tex-archive/help/Catalogue/entries/varwidth.html}{\nolinkurl{CTAN:help/Catalogue/entries/varwidth.html}}
+%
+% \bibitem{enumitem-zref}
+% \textit{The \xpackage{enumitem-zref} package} by \FC \\
+%   2010/11/28 ver 1.1 -- Extended references for enumitem pkg \\
+%   \href{http://www.ctan.org/tex-archive/help/Catalogue/entries/enumitem-zref.html}{\nolinkurl{CTAN:help/Catalogue/entries/enumitem-zref.html}}
+%  \label{enumitem-zref}
+%
+% \end{thebibliography}
+%
+% 
+% 
 % \begin{History}
 %
+%   \def\Version#1{\HistVersion{#1}\setitemize{name=#1,leftmargin=2em}\itemize}
+%
 %   \sectionformat\subsection[hang]{font=\large\bfseries\macrocodecolor}
 %
+%   \begin{Version}{2010/12/07 v1.5}
+%   \item Implementation of negativ width coefficients for \textt X columns (cf. \refitem{tabu X columns,2}[\nameref*{tabu X columns} point \ref]).
+%   \item Columns natural widths computation (for \textt{tabu spread} with \textt X columns and negativ coefficients)
+%         is based on the code of the \xpackage{varwidth} package by Donald Arseneau.
+%   \item \textt{longtabu} is now provided, based on the \xpackage{longtable} package by David Carlisle. \\
+%         \textt{longtabu} can be used just like \textt{tabu}.
+%   \item Vertical lines can be used whatever the catcode of \textbf\textbar\ is.
+%   \item \csref{savetabu} reports saved informations in the \xext{log} (\hyperref[debugshow]{\textt{debugshow}} option).
+%   \item \cs{savetabu} ... \cs{usetabu} now restores the \cs{halign} preamble rather than the \textt{tabu} preamble! \\
+%         \csref{preamble} can be use in the \textt{tabu} preamble to restore a \texttt{tabu} preamble.
+%   \item \csref{tabucline} is more robust with ``special'' preambles containing\, \texttbf>\, or\, \texttbf<\, tokens. \\
+%         \cs{tabucline} now takes care of \cs{arrayrulecolor} (package \xpackage{colortbl}).
+%   \item \Xpackage{enumitem-zref} package has been added to the documentation (see the link \refitem{2010/12/07 v1.5,1}[point 1])
+%   \item Optimisation of some parts of the code.
+%   \end{Version}
+%
 %   \begin{Version}{2010/11/22 v1.4}
 %   \item Compatibility improvement with \xpackage{linegoal} for the syntax: \\
 %     \cs{begin}\M*{tabu}\textt{ to\cs{linegoal}}\M*{...}
@@ -3720,13 +4331,12 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
 %         and also when \cs{minrowclearance} $>0$ (package \xpackage{colortbl}).
 %   \end{Version}
 %
-%
 %   \begin{Version}{2010/10/28 v1.1}
 %   \item First version.
 %   \end{Version}
 %
 % \end{History}
-%
+% 
 %
 % \PrintIndex
 %
diff --git a/Master/texmf-dist/source/latex/tabu/tabu.ins b/Master/texmf-dist/source/latex/tabu/tabu.ins
index 889294e144a..ffce078a079 100644
--- a/Master/texmf-dist/source/latex/tabu/tabu.ins
+++ b/Master/texmf-dist/source/latex/tabu/tabu.ins
@@ -8,7 +8,7 @@
 %% 
 %% This is a generated file.
 %% 
-%% tabu : 2010/11/22 v1.4 - tabu : Flexible LaTeX tabulars
+%% tabu : 2010/12/07 v1.5 - tabu : Flexible LaTeX tabulars
 %% 
 %% This work may be distributed and/or modified under the
 %% conditions of the LaTeX Project Public License, either
@@ -26,7 +26,7 @@
 \input docstrip.tex
 \Msg{************************************************************************}
 \Msg{* Installation}
-\Msg{* Package: 2010/11/22 v1.4 - tabu: Flexible LaTeX tabulars}
+\Msg{* Package: 2010/12/07 v1.5 - tabu: Flexible LaTeX tabulars}
 \Msg{************************************************************************}
 
 \keepsilent
@@ -37,7 +37,7 @@
 
 This is a generated file.
 
-tabu : 2010/11/22 v1.4 - tabu : Flexible LaTeX tabulars
+tabu : 2010/12/07 v1.5 - tabu : Flexible LaTeX tabulars
 
 This work may be distributed and/or modified under the
 conditions of the LaTeX Project Public License, either
@@ -60,7 +60,7 @@ Copyright (C) 2010 by Florent Chervet <florent.chervet@free.fr>
    \file{tabu.sty}{\from{tabu.dtx}{package}}%
 }
 
-\askforoverwritefalse
+\askforoverwritetrue
 \generate{%
    \file{tabu.drv}{\from{tabu.dtx}{driver}}%
 }
diff --git a/Master/texmf-dist/tex/latex/tabu/tabu.sty b/Master/texmf-dist/tex/latex/tabu/tabu.sty
index 4b09df52b1b..8d3aef8aa16 100644
--- a/Master/texmf-dist/tex/latex/tabu/tabu.sty
+++ b/Master/texmf-dist/tex/latex/tabu/tabu.sty
@@ -8,7 +8,7 @@
 %% 
 %% This is a generated file.
 %% 
-%% tabu : 2010/11/22 v1.4 - tabu : Flexible LaTeX tabulars
+%% tabu : 2010/12/07 v1.5 - tabu : Flexible LaTeX tabulars
 %% 
 %% This work may be distributed and/or modified under the
 %% conditions of the LaTeX Project Public License, either
@@ -25,8 +25,10 @@
 %% 
 
 \NeedsTeXFormat{LaTeX2e}[2005/12/01]
-\ProvidesPackage{tabu}[2010/11/22 v1.4 - flexible LaTeX tabulars (FC)]
+\ProvidesPackage{tabu}[2010/12/07 v1.5 - flexible LaTeX tabulars (FC)]
 \RequirePackage{array}[2008/09/09]
+\RequirePackage{varwidth}[2009/03/30]
+\let\DEBUG\@gobble%\message
 \AtEndOfPackage{\tabu@AtEnd\let\tabu@AtEnd\@undefined}
 \let\tabu@AtEnd\@empty
 \def\TMP@EnsureCode#1#2{%
@@ -40,27 +42,34 @@
 \TMP@EnsureCode{124}{12}% |
 \TMP@EnsureCode{0}{12}%  ^^@
 \TMP@EnsureCode{36}{3}% $ = math shift
-\let\tabu@message\@gobble
-\def\tracingtabu{\let\tabu@message\message}
-\let\tabudefaulttarget\linewidth
-\DeclareOption{debugshow}{\tracingtabu}
+\let\tabu@message         \@gobble
+\let\tabu@message@save    \@gobble
+\let\tabu@debug           \@gobble
+\def\tracingtabu{%
+   \let\tabu@message \message
+   \let\tabu@message@save \tabu@tracing@save
+   \@ifnextchar={\tabu@tracing}{}}
+\def\tabu@tracing{\begingroup\afterassignment\tabu@tr@cing\count@}
+\def\tabu@tr@cing{\expandafter\endgroup\ifnum\count@>\@ne
+   \let\tabu@debug\message\else\let\tabu@debug\@gobble\fi}
+\DeclareOption{debugshow}{\AtEndOfPackage\tracingtabu}
+\let\tabudefaulttarget    \linewidth
 \DeclareOption{linegoal}{%
-   \AtEndOfPackage{\RequirePackage{linegoal}[2010/10/31]}%
-   \def\tabudefaulttarget{\linegoal}% \linegoal is \linewidth if not pdfTeX
-}% linegoal option
+   \AtEndOfPackage{%
+      \RequirePackage{linegoal}[2010/12/07]%
+      \let\tabudefaulttarget \linegoal% \linegoal is \linewidth if not pdfTeX
+}}
 \DeclareOption{delarray}{%
    \AtEndOfPackage{\RequirePackage{delarray}}%
-}% delarray option
+}
 \DeclareOption{light}{%
    \AtEndOfPackage{%
-      \let\tabu@prepnext@tok \prepnext@tok
-      \let\tabu@save@decl \save@decl
-      \let\tabu@rowfont \tabu@norowfont
-      \let\tabucline \tabu@nocline
-      \let\tabu@firstcline \relax
-      \let\tabu@lines \relax
+   \let\tabu@prepnext@tok \prepnext@tok    \let\tabu@save@decl \save@decl
+   \let\tabu@rowfont      \tabu@norowfont  \let\tabucline      \tabu@nocline
+   \let\tabu@firstcline   \relax           \let\tabu@lines     \relax
+   \let\tabu@setup@everycr\relax
    }
-}% light option
+}
 \def\tabu@norowfont{\PackageError{tabu}
    {\string\rowfont\space is not available with option `light'}\@ehd}
 \def\tabu@nocline{\PackageError{tabu}
@@ -68,158 +77,174 @@
 \ProcessOptions
 \AtBeginDocument{%
    \@ifundefined{NC@rewrite@X}{\newcolumntype{X}{}}{}% new column X if not exists
-   \expandafter\in@\expandafter\@arrayright\expandafter{\endarray}%
-   \ifin@ \let\tabu@endarray\endarray
-   \else \tabu@fix@arrayright \fi % <fix for colortbl & arydshln (delarray)>
+   \expandafter\in@ \expandafter\@arrayright\expandafter{\endarray}%
+   \ifin@ \let\tabu@endarray \endarray
+   \else  \tabu@fix@arrayright \fi % <fix for colortbl & arydshln (delarray)>
    \@ifpackageloaded{colortbl} \tabu@colortbltrue \tabu@colortblfalse
+   \@ifpackageloaded{arydshln}{}
+      {\let\tabu@adl@fix \relax \let\tabu@adl@endTRIAL \@empty}%
+   \@ifpackageloaded{longtable}{}{\let\longtabu \tabu@nolongtabu}%
 }
-\newcount\tabu@cnt
-\newcount\tabu@nbcols
-\newcount\tabu@X@cols
-\newcount\tabu@start
-\newcount\tabu@stop
-\newdimen\tabu@target
-\newdimen\tabu@spreadtarget
-\newdimen\tabu@naturalX
-\newdimen\tabucolX
-\newdimen\tabu@X@sum
-\newif\iftabu@measuring
-\newif\iftabu@spread
-\newif\iftabu@nested
-\newif\iftabu@firstcline
-\newsavebox\tabu@box
-\chardef\tabu@arstrutbox=\@arstrutbox
+\newcount \tabu@cnt
+\newcount \tabu@nbcols
+\newcount \tabu@X@cols
+\newcount \tabu@start
+\newcount \tabu@stop
+\newcount \tabu@nested
+\newdimen \tabu@target
+\newdimen \tabu@spreadtarget
+\newdimen \tabu@naturalX
+\newdimen \tabucolX
+\newdimen \tabu@X@sum
+\newdimen \tabucolX@error \tabucolX@error=1em
+\newif \iftabu@measuring
+\newif \iftabu@spread
+\newif \iftabu@firstcline
+\newif \iftabu@negcoef
+\newsavebox \tabu@box
+\chardef \tabu@arstrutbox=\@arstrutbox
 \let\tabu@vcenter \vcenter
 \def\tabu@gobblespace#1 {#1}
+\def\tabu@gobbleopt#1{\@ifnextchar [{\tabu@gobble@pt{#1}}{#1}}%]
+\def\tabu@gobble@pt#1[#2]{#1}
+\def\tabu@save@decl{%
+   \toks\count@ = \expandafter{\the\toks\expandafter\count@\@nextchar}%
+}% \tabu@save@decl
 \newcommand\tabu@NC@rewrite@X[1][]{\tabu@rewrite@X{#1}%
                                  \let\@halignto \relax
-                  \expandafter \NC@find \tabucolX@spec}
-\expandafter\def\csname NC@rewrite@\string\usetabu\endcsname#1{%
+                  \expandafter \NC@find \tabucolX@rw}
+\def\tabu@newcolumntype #1{%
+   \expandafter\def\csname NC@find@\string#1\endcsname##1#1{\NC@{##1}}%
+   \expandafter\def\csname NC@rewrite@\string#1\endcsname%
+}% \tabu@newcolumntype
+\tabu@newcolumntype \usetabu #1{%
    \ifx\\#1\\\tabu@saveerr{}\else
       \@ifundefined{tabu@saved@\string#1}
          {\tabu@saveerr{#1}}
          {\let\tabu@rewrite@X \tabu@rewrite@Xrestore
-         \def\tabu@temp{\xdef\tabu@usetabu{%
-            \col@sep \the\col@sep\relax
-            \arrayrulewidth \the\arrayrulewidth\relax
-            \@tempdima \ht\@arstrutbox \advance\@tempdima -\extrarowheight
-            \extrarowheight \the\extrarowheight\relax
-            \advance\@tempdima \extrarowheight
-            \ht\@arstrutbox \@tempdima
-            \extratabsurround \the\extratabsurround\relax
-            \doublerulesep \the\doublerulesep\relax}}%
-         \aftergroup \tabu@usetabu
-         \csname tabu@saved@\string#1\expandafter\endcsname}%
+          \csname tabu@saved@\string#1\expandafter\endcsname\expandafter\z@}%
    \fi
 }% \NC@rewrite@\usetabu
-\expandafter\def\csname NC@find@\string\usetabu\endcsname#1\usetabu{\NC@{#1}}
-\expandafter\def\csname NC@rewrite@\string\tabu@rewritefirst\endcsname{%
-   \ifx\tabu@lines\relax
-   \NC@list\expandafter{\expandafter\NC@do \expandafter\usetabu
-                        \NC@do X\NC@do\tabu@rewritelast}%
-   \else
-   \NC@list\expandafter{\expandafter\NC@do \expandafter\usetabu
-                        \expandafter\NC@do \expandafter|\tabu@NC@list
-                        \NC@do X\NC@do\tabu@rewritelast}%
-      \tabu@lines % defines NC@rewrite@| for tabu only (inside @mkpream group)
+\tabu@newcolumntype \preamble #1{%
+   \ifx\\#1\\\tabu@saveerr{}\else
+      \@ifundefined{tabu@saved@\string#1}
+         {\tabu@saveerr{#1}}
+         {\csname tabu@saved@\string#1\expandafter\endcsname\expandafter\@ne}%
    \fi
-   \let\save@decl \tabu@save@decl % inversion of tokens in text mode
-   \let\NC@rewrite@X \tabu@NC@rewrite@X
-   \aftergroup \tabu@global@temp
+}% \NC@rewrite@\preamble
+\tabu@newcolumntype \tabu@rewritefirst{%
+   \tabu@X@cols \z@  \let\NC@rewrite@X \tabu@NC@rewrite@X
+   \let\tabu@dimexpr \relax \aftergroup \tabu@global@temp
+   \aftergroup \tabu@restore@NC@list
+   \NC@list{\NC@do\usetabu \NC@do\preamble \NC@do *}%
+   \tabu@lines % defines NC@rewrite@| for tabu only (inside @mkpream group)
+   \NC@list\expandafter{\the\NC@list \NC@do X\NC@do\tabu@rewritelast}%
+   \ifcat$\d@llarend\else
+      \let\save@decl \tabu@save@decl \fi % no inversion of tokens in text mode
    \NC@find \tabu@rewritelast
 }% NC@rewrite@\tabu@rewritefirst
-\expandafter\def\csname NC@find@\string\tabu@rewritefirst\endcsname
-                                          #1\tabu@rewritefirst{\NC@{#1}}
-\def\tabu@rewritefirst{%
-   \edef\tabu@NC@list{\the\NC@list}%
-   \NC@list{\NC@do \tabu@rewritefirst \NC@do *}%
-}% \tabu@rewritefirst
-\expandafter\def\csname NC@rewrite@\string\tabu@rewritelast\endcsname{%
-   \global\NC@list\expandafter{\tabu@NC@list}%
-   \futurelet \tabu@temp \tabu@rewritelast
-}% \NC@rewrite@\tabu@rewritelast
-\expandafter\def\csname NC@find@\string\tabu@rewritelast\endcsname
-                                          #1\tabu@rewritelast{\NC@{#1}}
-\def\tabu@rewritelast{%
+\def\tabu@restore@NC@list{\NC@list\expandafter{\tabu@NC@list}}
+\tabu@newcolumntype \tabu@rewritelast{%
+   \NC@list\expandafter{\tabu@NC@list}%
+   \let\tabu@next \NC@find
    \ifx \@halignto\relax   % found a X column
-      \let\tabu@temp \@empty
       \ifx \tabu@halignto\relax % X column measure
+         \tabu@global@Xnested
+         \iftabu@negcoef \aftergroup\tabu@negcoeftrue \fi
          \aftergroup \tabu@prep@TRIAL
       \else \aftergroup \tabu@setup@everycr
       \fi
    \else
-      \ifdim \tabu@target=\z@ \let\tabu@temp \@empty
-      \else
-         \if |\noexpand\tabu@temp\def\tabu@temp{@{\extracolsep\@flushglue}}\else
-         \if !\noexpand\tabu@temp\def\tabu@temp{@{\extracolsep\@flushglue}}\else
-                                 \def\tabu@temp{!{\extracolsep\@flushglue}}\fi\fi
-      \fi
-      \aftergroup\tabu@setup@everycr
+      \aftergroup \tabu@setup@everycr
+      \ifdim \tabu@target=\z@ \else
+         \let\tabu@next \tabu@rewritelast \fi % <need \extracolsep ?>
    \fi
    \let\@halignto \tabu@halignto
-   \expandafter\NC@find \tabu@temp
+   \tabu@next
+}% \NC@rewrite@\tabu@rewritelast
+\def\tabu@rewritelast{\futurelet\tabu@temp \tabu@rewrite@last}
+\def\tabu@rewrite@last{%
+   \ifx \tabu@temp\@sptoken
+      \expandafter\tabu@gobblespace \expandafter\tabu@rewritelast
+   \else
+      {\endlinechar\m@ne\scantokens{\let\x |}%
+      \expandafter}\ifx \x\tabu@temp
+         \def\tabu@next {\NC@find @{\extracolsep\@flushglue}}\else
+      {\endlinechar\m@ne\scantokens{\let\x !}%
+      \expandafter}\ifx \x\tabu@temp
+         \def\tabu@next {\NC@find @{\extracolsep\@flushglue}}\else
+         \def\tabu@next {\NC@find !{\extracolsep\@flushglue}}\fi\fi
+      \expandafter\tabu@next
+   \fi
 }% \tabu@rewritelast
+\def\tabu@global@Xnested{\global\expandafter\let
+         \csname tabu@global@X\the\tabu@nested\endcsname\tabu@global@X
+   \aftergroup\let \aftergroup\tabu@global@X
+   \expandafter\aftergroup \csname tabu@global@X\the\tabu@nested\endcsname
+}% \tabu@global@Xnested
 \newif\iftabu@colortbl
-\def\tabu@nowrite{% cancels a \write command (tabularx method)
-   \begingroup
-     \def\let{\afterassignment\endgroup\toks@}%
-        \afterassignment\let\count@
-}% \tabu@nowrite
+\def\tabu@nowrite#1#{{\afterassignment}\toks@}
 \let\tabu@write\write
+\let\tabu@immediate\immediate
+\protected\def\tabu@GenericError{\begingroup
+   \def\immediate\write{\aftergroup\endgroup
+      \tabu@immediate\tabu@write}\tabu@GenericErrorORI}%
+\let\tabu@GenericErrorORI \GenericError
+\protected\def\tabu@warn{\begingroup
+   \def\immediate\write{\aftergroup\endgroup
+      \tabu@immediate\tabu@write}\PackageWarning{tabu}}
 \def\tabu{%
-   \ifmmode \def\endtabu{\endarray}%
-   \else    \def\endtabu{\endtabular}\fi
+   \ifmmode \def\tabu@{\array}\def\endtabu{\endarray}%
+   \else    \def\tabu@{\tabular}\def\endtabu{\endtabular}\fi
    \tabu@setup \tabu@settarget
 }% \tabu
+\def\longtabu{%
+   \ifmmode\PackageError{tabu}{longtabu not allowed in math mode}\fi
+   \def\tabu@{\longtable}\def\endlongtabu{\endlongtable}%
+   \let\tabu@arrayleft@measure \tabu@long@arrayleft@measure
+   \let\tabu@endTRIAL \tabu@long@endTRIAL
+   \tabu@setup \tabu@settarget
+}% \longtabu
+\def\tabu@nolongtabu{\PackageError{tabu}
+   {longtabu requires the longtable package}\@ehd}
 \def\tabu@setup{%
-   \let\adl@xarraydashrule \tabu@adl@xarraydashrule % <fix> arydshln
-   \let\adl@act@endpbox \tabu@adl@act@endpbox       % <fix> arydshln
-   \let\adl@act@@endpbox \tabu@adl@act@endpbox      % <fix> arydshln
-   \let\@preamerror \@preamerr                      % <fix> arydshln
-   \let\endarray \tabu@endarray          % <fix> colortbl & arydshln (delarray)
+   \tabu@adl@fix \let\endarray \tabu@endarray % <fix> colortbl & arydshln (delarray)
    \let\tabu@global@temp \@empty \let\tabu@global@X \@empty
-   \ifx\verbatim \tabu@sanitizetext
-         \tabu@nestedtrue
-         \def\tabu@aligndefault{t}\def\tabudefaulttarget{\linewidth}%
-   \else \tabu@nestedfalse
-         \def\tabu@aligndefault{c}%
-         \global\tabu@footnotes{}%
-         \aftergroup\the\aftergroup\tabu@footnotes
-         \ifdim\parindent>\z@ \ifx\linewidth\tabudefaulttarget
-         \everypar\expandafter{%                    % correction for indentation
+   \ifx \verbatim\tabu@sanitizetext      % <nested tabu>
+      \tabu@setup@saveglobal
+      \advance\tabu@nested \@ne
+      \def\tabu@aligndefault{t}\let\tabudefaulttarget \linewidth
+   \else
+      \def\tabu@aligndefault{c}\edef\tabu@hfuzz {\the\hfuzz}%
+      \global\tabu@footnotes{}\aftergroup\the\aftergroup\tabu@footnotes
+      \ifdim\parindent>\z@ \ifx\linewidth\tabudefaulttarget
+         \everypar\expandafter{%         % correction for indentation
             \the\everypar\everypar\expandafter{\the\everypar}%
             \setbox\z@=\lastbox
             \ifdim\wd\z@>\z@ \advance\linewidth -\wd\z@\fi
             \box\z@
             }%
-         \fi\fi
+      \fi\fi
    \fi
-   \let\@footnotetext \tabu@footnotetext
-   \let\@xfootnotetext\tabu@xfootnotetext
-   \let\@xfootnote \tabu@xfootnote
-   \let\centering \tabu@centering
-   \let\raggedright \tabu@raggedright
-   \let\raggedleft \tabu@raggedleft
-   \let\@trivlist \tabu@trivlist           %<restore \\=\@centercr inside lists>
-   \let\tabudecimal \tabu@tabudecimal
-   \let\verbatim \tabu@sanitizetext
-   \let\fbox \tabu@fbox
-   \let\prepnext@tok \tabu@prepnext@tok            % <for rowfont and tabucline>
-   \let\rowfont \tabu@rowfont
+   \let\@footnotetext \tabu@footnotetext \let\@xfootnotetext \tabu@xfootnotetext
+   \let\@xfootnote    \tabu@xfootnote    \let\centering      \tabu@centering
+   \let\raggedright   \tabu@raggedright  \let\raggedleft     \tabu@raggedleft
+   \let\@trivlist     \tabu@trivlist     %<restore \\=\@centercr inside lists>
+   \def\tabudecimal   {\tabu@tabudecimal}\let\verbatim       \tabu@sanitizetext
+   \let\fbox          \tabu@fbox         \let\rowfont        \tabu@rowfont
+   \let\prepnext@tok  \tabu@prepnext@tok %<for \rowfont and \tabucline>
    \everycr{}\let\tabu@everycr \everycr
-   \tabu@spreadfalse \tabu@measuringfalse
-   \edef\tabu@hfuzz{\ifdim\hfuzz<.1\p@ .1\p@\else\the\hfuzz\fi}%
-   \tabu@rewritefirst
+   \tabu@spreadfalse  \tabu@measuringfalse \tabu@negcoeffalse
+   \edef\tabu@NC@list{\the\NC@list}\NC@list{\NC@do\tabu@rewritefirst \NC@do *}%
 }% \tabu@setup
-\def\tabu@save@decl{% no inversion on tokens when not in math mode
-   \ifcat$\d@llarend
-      \toks\count@\expandafter\expandafter\expandafter{%
-               \expandafter\@nextchar \the\toks\count@}%
-   \else
-      \toks\count@\expandafter\expandafter\expandafter{%
-         \expandafter\the\expandafter\toks\expandafter\count@\@nextchar}%
-   \fi
-}% \tabu@save@decl
+\def\tabu@setup@saveglobal{%
+   \expandafter\xdef\csname tabu@global@\the\tabu@nested\endcsname{%
+      \global\tabu@X@cols \the\tabu@X@cols\relax
+      \global\tabu@naturalX \the\tabu@naturalX\relax
+      \gdef\noexpand\tabu@naturalX@min {\tabu@naturalX@min}%
+      \gdef\noexpand\tabu@naturalX@max {\tabu@naturalX@max}}%
+      \expandafter\aftergroup\csname tabu@global@\the\tabu@nested\endcsname
+}% \tabu@setup@saveglobal
 \def\tabu@settarget{\futurelet\@let@token \tabu@sett@rget}
 \def\tabu@sett@rget{\tabu@target\z@
    \ifcase \ifx \bgroup\@let@token 0\else
@@ -228,62 +253,62 @@
            \if t\@let@token 2\else
            \if s\@let@token 3\else
            \m@ne\fi\fi\fi\fi\fi\relax
-       \expandafter\tabu@begin
-   \or \expandafter\tabu@gobblespace\expandafter\tabu@settarget
-   \or \expandafter\tabu@to
-   \or \expandafter\tabu@spread
-   \else\expandafter\tabu@begin
+         \expandafter\tabu@begin
+   \or   \expandafter\tabu@gobblespace\expandafter\tabu@settarget
+   \or   \expandafter\tabu@to
+   \or   \expandafter\tabu@spread
+   \else \expandafter\tabu@begin
    \fi
 }% \tabu@sett@rget
 \def\tabu@to to{\def\@halignto{to}\tabu@gettarget}
 \def\tabu@spread spread{\tabu@spreadtrue\def\@halignto{spread}\tabu@gettarget}
-\def\tabu@gettarget{\afterassignment\tabu@linegoaltarget\tabu@target}
-\def\tabu@linegoaltarget{\futurelet\tabu@temp\tabu@linegoal@target}
-\def\tabu@linegoal@target{\ifx\tabu@temp\LNGL@setlinegoal
-   \LNGL@setlinegoal
-      \expandafter\expandafter\expandafter \tabu@begin
-      \expandafter\@gobble
-   \else \expandafter\tabu@begin
-   \fi
+\def\tabu@gettarget {\afterassignment\tabu@linegoaltarget \tabu@target}
+\def\tabu@linegoaltarget {\futurelet\tabu@temp \tabu@linegoal@target}
+\def\tabu@linegoal@target {%
+   \ifx \tabu@temp\LNGL@setlinegoal
+        \LNGL@setlinegoal \expandafter \@firstoftwo \fi % @gobbles \LNGL@setlinegoal
+   \tabu@begin
 }% \tabu@linegoal@target
-\def\tabu@begin#1#{%
-   \edef\@halignto{\ifdim\tabu@target>\z@ \@halignto\the\tabu@target\fi}%
+\def\tabu@begin #1#{%
+   \edef\@halignto {\ifdim\tabu@target>\z@ \@halignto\the\tabu@target\fi}%
    \let\tabu@halignto \@halignto
-   \expandafter\@testopt \expandafter\tabu@@begin \tabu@aligndefault #1\@nil
+   \@testopt \tabu@@begin \tabu@aligndefault #1\@nil
 }% \tabu@begin
-\def\tabu@@begin[#1]#2\@nil#3{%
-   \edef\tabu@align{#1}%
-   \edef\tabu@saved{%
+\def\tabu@@begin [#1]#2\@nil#3{%
+   \tabu@preparesave{#3}%     <for \savetabu>
+   \def\tabu@align {#1}%
+   \tabu@ [{\tabu@align}]#2{\tabu@rewritefirst #3}%
+}% \tabu@@begin
+\def\tabu@preparesave #1{%
+   \edef\tabu@savedparam{%
       \ifmmode \col@sep \the\arraycolsep
       \else    \col@sep \the\tabcolsep     \fi\relax
-      \arrayrulewidth \the\arrayrulewidth\relax
-      \extrarowheight \the\extrarowheight\relax
+      \arrayrulewidth   \the\arrayrulewidth\relax
+      \doublerulesep    \the\doublerulesep\relax
+      \extrarowheight   \the\extrarowheight\relax
       \extratabsurround \the\extratabsurround\relax
-      \doublerulesep \the\doublerulesep\relax}%
-   \expandafter\def\expandafter\tabu@saved\expandafter{\tabu@saved
-            \tabu@temp \edef\tabu@halignto{to\the\tabu@target}\NC@find #3}%
-   \ifmmode \expandafter\array
-   \else    \expandafter\tabular
-   \fi      [{#1}]#2{\tabu@rewritefirst #3}%
-}% \tabu@@begin
+      \def\noexpand\arraystretch {\arraystretch}%
+      \iftabu@colortbl \minrowclearance\the\minrowclearance\relax \fi}%
+   \def\tabu@savedpream {\edef\tabu@halignto{to\the\tabu@target}\NC@find #1}%
+}% \tabu@preparesave
 \newtoks\tabu@footnotes
-\long\def\tabu@footnotetext#1{%
+\long\def\tabu@footnotetext #1{%
    \edef\@tempa{\the\tabu@footnotes
       \noexpand\footnotetext [\the\csname c@\@mpfn\endcsname]}%
-   \global\tabu@footnotes\expandafter{\@tempa{#1}}}%
-\long\def\tabu@xfootnotetext[#1]#2{%
+   \global\tabu@footnotes\expandafter{\@tempa {#1}}}%
+\long\def\tabu@xfootnotetext [#1]#2{%
   \global\tabu@footnotes\expandafter{\the\tabu@footnotes
-                           \footnotetext[{#1}]{#2}}}
+                              \footnotetext [{#1}]{#2}}}
 \let\tabu@xfootnote \@xfootnote
 \long\def\tabu@Hy@ftntext{\tabu@Hy@ftntxt {\the \c@footnote }}
-\long\def\tabu@Hy@xfootnote[#1]{%
+\long\def\tabu@Hy@xfootnote [#1]{%
    \begingroup
       \value\@mpfn #1\relax
       \protected@xdef \@thefnmark  {\thempfn}%
    \endgroup
    \@footnotemark \tabu@Hy@ftntxt {#1}%
 }% \tabu@Hy@xfootnote
-\long\def\tabu@Hy@ftntxt#1#2{%
+\long\def\tabu@Hy@ftntxt #1#2{%
    \edef\@tempa{%
       \the\tabu@footnotes
       \begingroup
@@ -296,92 +321,78 @@
           }%
       }%
       \global\tabu@footnotes\expandafter{%
-          \@tempa{#2}%
+          \@tempa {#2}%
         \endgroup
       }%
 }% \tabu@Hy@ftntxt
-\long\def\tabu@Hy@footnotetext#1#2{%
+\long\def\tabu@Hy@footnotetext #1#2{%
    \H@@footnotetext{%
       \ifHy@nesting
-         \hyper@@anchor{#1}{#2}%
+         \hyper@@anchor {#1}{#2}%
       \else
          \Hy@raisedlink{%
-            \hyper@@anchor{#1}{\relax}%
+            \hyper@@anchor {#1}{\relax}%
          }%
-         \def\@currentHref{#1}%
-         \let\@currentlabelname\@empty
+         \def\@currentHref {#1}%
+         \let\@currentlabelname \@empty
          #2%
       \fi
    }%
 }% \tabu@Hy@footnotetext
 \AtBeginDocument{%
-   \@ifpackageloaded{hyperref}
-      {\ifHy@hyperfootnotes
-         \let\tabu@footnotetext \tabu@Hy@ftntext
-         \let\tabu@xfootnote    \tabu@Hy@xfootnote
-       \fi}
-      {}%
-}%
-\def\tabu@rewrite@X#1{\tabu@Xarg{#1}%
-   \iftabu@spread \tabu@rewrite@Xspread
-   \else          \tabu@rewrite@Xto
+   \csname\ifcsname ifHy@hyperfootnotes\endcsname
+    ifHy@hyperfootnotes\else iffalse\fi\endcsname
+      \let\tabu@footnotetext \tabu@Hy@ftntext
+      \let\tabu@xfootnote    \tabu@Hy@xfootnote
    \fi
-}% \tabu@rewrite@X
-\def\tabu@rewrite@Xnested#1{\in@ ${#1}\ifin@
-   \def\tabucolX@spec{>{$}p{\tabucolX}<{$}}\else
-   \def\tabucolX@spec{p{\tabucolX}}\fi}
-\def\tabu@rewrite@Xrestore#1{\tabu@Xarg{#1}\let\tabucolX@spec\tabu@temp}%
-\def\tabu@rewrite@Xto{%
+}
+\def\tabu@rewrite@X #1{\tabu@Xarg {#1}%
+   \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \relax
    \iftabu@measuring % not the first X column found in preamble
-      \xdef\tabu@global@X {\tabu@global@X
-         \advance\tabu@X@sum \the\tabu@X@sum\relax}%
+      \edef\tabu@global@X {\tabu@global@X
+            \advance\tabu@X@cols \@ne
+            \def\csname tabu@X\the\tabu@X@cols\endcsname {\strip@pt\tabu@X@sum}%
+            \advance\tabu@X@sum \the\tabu@X@sum\relax}%
    \else % first X column found in preamble
       \tabu@measuringtrue
+      \iftabu@spread \tabu@spreadtarget\tabu@target \tabu@target\z@
+      \else          \tabu@spreadtarget \z@ \fi
       \ifdim\tabu@target=\z@
-         \setlength \tabu@target \tabudefaulttarget
-      \fi
-      \xdef\tabu@global@X{%
-         \tabu@X@sum \the\tabu@X@sum\relax
-         \tabu@target \the\tabu@target\relax}%
-      \let\tabu@halignto \relax
-   \fi
-}% \tabu@rewrite@Xto
-\def\tabu@rewrite@Xspread{% tabu spread with X columns: need to store each coef
-   \iftabu@measuring % not the first X column found in preamble
-      \advance\tabu@X@cols \@ne
-      \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \relax
-      \xdef\tabu@global@X {\tabu@global@X
-            \advance\tabu@X@cols\@ne
-            \advance\tabu@X@sum \the\tabu@X@sum\relax
-            \def\csname tabu@X\the\tabu@X@cols\endcsname{\strip@pt\tabu@X@sum}}%
-   \else % first X column found in preamble
-      \tabu@measuringtrue
-      \tabu@X@cols \@ne  \tabu@spreadtarget=\tabu@target
-      \setlength \tabu@target \tabudefaulttarget
-      \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \relax
-      \xdef\tabu@global@X {%
+         \setlength\tabu@target \tabudefaulttarget
+         \tabu@message{(tabu) Default target:
+            \ifx\tabudefaulttarget\linewidth\string\linewidth
+            \else\ifx\tabudefaulttarget\linegoal\string\linegoal
+            \fi\fi=\the\tabu@target \on@line, page \the\c@page}\fi
+      \tabu@message{\tabu@titles}%
+      \edef\tabu@global@X {\tabu@global@X
          \tabu@X@cols \@ne
-         \tabu@X@sum \the\tabu@X@sum\relax
+         \def\csname tabu@X1\endcsname{\strip@pt\tabu@X@sum}%
+         \tabu@X@sum  \the\tabu@X@sum\relax
          \tabu@target \the\tabu@target\relax
-         \tabu@spreadtarget \the\tabu@spreadtarget\relax
-         \def\csname tabu@X\the\tabu@X@cols\endcsname{\strip@pt\tabu@X@sum}}%
+         \tabu@spreadtarget \the\tabu@spreadtarget\relax}%
       \let\tabu@halignto \relax
    \fi
-}% \tabu@rewrite@Xspread
+}% \tabu@rewrite@X
+\let\tabu@@rewrite@X \tabu@rewrite@X
+\def\tabu@rewrite@Xnested #1{\in@ ${#1}\ifin@
+   \def\tabucolX@rw {>{$}p{\tabucolX}<{$}}\else
+   \def\tabucolX@rw {p{\tabucolX}}\fi}
+\def\tabu@rewrite@Xrestore #1{\tabu@gobbleopt{\def\tabucolX@rw{l}}}
 \def\tabu@Xarg#1{%
-   \ifx\\#1\\%    <shortcut when no option>
-      \tabu@X@sum \p@
-      \def\tabucolX@spec{p{\tabucolX}}%
-      \edef\tabu@temp{p{\the\tabucolX}}%  <required for \usetabu>
-   \else
-      \tabu@X@sum \z@
-      \let\tabucolX@align \@empty
-      \let\tabucolX@spec \@empty
-      \let\tabu@Xmath \relax
-      \tabu@Xparse {}#1\relax\@nnil
-   \fi
+  \advance\tabu@X@cols \@ne
+  \tabu@wdlet\tabu@X@cols \z@
+  \ifx\\#1\\%    <shortcut when no option>
+     \tabu@X@sum \p@
+     \edef\tabucolX@rw {p{\tabu@dimexpr{\the\tabu@X@cols}{\tabucolX}}}%
+     \edef\tabu@temp {p{\the\tabucolX}}%  <required for \usetabu>
+  \else
+     \tabu@X@sum \z@
+     \let\tabucolX@align \@empty \let\tabucolX@rw \@empty
+     \let\tabu@Xmath     \@empty \let\tabu@temp     \@empty
+     \tabu@Xparse {}#1\relax\@nnil
+  \fi
 }% \tabu@Xarg
-\def\tabu@Xparse#1{\futurelet\@let@token\tabu@Xtest}
+\def\tabu@Xparse #1{\futurelet\@let@token \tabu@Xtest}
 \expandafter\def\expandafter\tabu@Xparsespace\space{\tabu@Xparse{}}
 \def\tabu@Xtest{%
    \ifcase \ifx \@nnil\@let@token \z@ \else
@@ -393,28 +404,29 @@
            \if l\@let@token 4\else
            \if c\@let@token 5\else
            \if r\@let@token 6\else
-           \if .\@let@token 7\else
-           \ifx \@sptoken\@let@token 8\else
-           \if L\@let@token 9\else
-           \if C\@let@token 10\else
-           \if R\@let@token 11\else
+           \if L\@let@token 7\else
+           \if C\@let@token 8\else
+           \if R\@let@token 9\else
+           \ifx \@sptoken\@let@token 10\else
+           \if .\@let@token 11\else
+           \if -\@let@token 11\else
            \ifcat $\@let@token 12\else
-           13\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\relax
-       \tabucolX@do \expandafter\remove@to@nnil
-   \or \tabu@Xcolspec{p}%
-   \or \tabu@Xcolspec{m}%
-   \or \tabu@Xcolspec{b}%
-   \or \tabu@Xalign{>{\raggedright}}%
-   \or \tabu@Xalign{>{\centering}}%
-   \or \tabu@Xalign{>{\raggedleft}}%
-   \or \expandafter\tabu@Xcoef
-   \or \expandafter\tabu@Xparsespace
-   \or \tabu@Xalign{>{\RaggedRight}}%
-   \or \tabu@Xalign{>{\Centering}}%
-   \or \tabu@Xalign{>{\RaggedLeft}}%
-   \or \let\tabu@Xmath=$\expandafter\tabu@Xparse
+           13\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\relax
+       \tabucolX@do \expandafter \remove@to@nnil
+   \or \tabu@Xtype {p}%
+   \or \tabu@Xtype {m}%
+   \or \tabu@Xtype {b}%
+   \or \tabu@Xalign \raggedright
+   \or \tabu@Xalign \centering
+   \or \tabu@Xalign \raggedleft
+   \or \tabu@Xalign \RaggedRight
+   \or \tabu@Xalign \Centering
+   \or \tabu@Xalign \RaggedLeft
+   \or \expandafter \tabu@Xparsespace
+   \or \expandafter \tabu@Xcoef
+   \or \let\tabu@Xmath=$\expandafter \tabu@Xparse
    \or \tabu@Xcoef{}%
-   \else \expandafter\tabu@Xparse
+   \else\expandafter \tabu@Xparse
    \fi
 }% \tabu@Xtest
 \def\tabu@Xalign#1{%
@@ -422,166 +434,240 @@
       {Duplicate horizontal alignment specification}\fi
    \def\tabucolX@align{#1}\expandafter\tabu@Xparse
 }% \tabu@Xalign
-\def\tabu@Xcolspec#1{%
-   \ifx\tabucolX@spec\@empty\else \PackageWarning{tabu}
+\def\tabu@Xtype#1{%
+   \ifx \tabucolX@rw\@empty \else \PackageWarning{tabu}
       {Duplicate vertical alignment specification}\fi
-   \def\tabucolX@spec{#1}\expandafter\tabu@Xparse
-}% \tabu@Xcolspec
-\def\tabu@Xcoef#1{\def\@tempa{#1}%
-   \afterassignment\tabu@Xc@ef \tabu@cnt
+   \def\tabucolX@rw{#1}\expandafter\tabu@Xparse
+}% \tabu@Xtype
+\def\tabu@Xcoef#1{\edef\tabu@temp{\tabu@temp#1}%
+   \afterassignment\tabu@Xc@ef \tabu@cnt\number\if-#10\fi
 }% \tabu@Xcoef
 \def\tabu@Xc@ef{%
-   \advance\tabu@X@sum \@tempa\the\tabu@cnt\p@
+   \advance\tabu@X@sum \tabu@temp\the\tabu@cnt\p@
    \tabu@Xparse{}%
 }% \tabu@Xc@ef
 \def\tabucolX@do{%
-   \ifx\tabucolX@spec\@empty \def\tabucolX@spec{p}\fi
-   \ifdim \tabu@X@sum=\z@ \tabu@X@sum \p@\fi
+   \ifx\tabucolX@rw\@empty \def\tabucolX@rw{p}\fi
+   \ifdim\tabu@X@sum<\z@ \tabu@negcoeftrue
+                         \tabu@X@sum \m@ne\tabu@X@sum
+                         \tabu@wdlet \tabu@X@cols \p@
+   \else \ifdim \tabu@X@sum=\z@ \tabu@X@sum \p@ \fi
+   \fi
    \begingroup
-      \edef\tabucolX@spec##1{\tabucolX@spec{##1}}%
-      \edef\tabu@temp{\dimexpr\strip@pt\tabu@X@sum \tabucolX \relax}%
-      \toks@\expandafter{\tabucolX@align}%
-      \edef\x{%
-         \def\noexpand\tabu@temp{%
-            \ifx \tabu@Xmath\relax\else >{$}\fi
-            \the\toks@ \tabucolX@spec{\the\tabu@temp}%
-            \ifx \tabu@Xmath\relax\else <{$}\fi}%
-         \def\noexpand\tabucolX@spec{%
-            \ifx \tabu@Xmath\relax\else >{$}\fi
-            \the\toks@ \tabucolX@spec{\tabu@temp}%
-            \ifx \tabu@Xmath\relax\else <{$}\fi}%
-      }\expandafter\endgroup\x
+      \toks@\expandafter {\tabucolX@align}%
+      \edef\tabu@temp {\strip@pt\tabu@X@sum \tabucolX}%
+      \edef\tabucolX@rw##1{%
+         \ifx$\tabu@Xmath>{\noexpand\the\toks@ $}\else
+         \ifx \tabucolXalign\@empty \else
+            >{\noexpand\the\toks@}\fi\fi
+            \tabucolX@rw{##1}%
+         \ifx$\tabu@Xmath<{$}\fi}%
+      \edef\x{\endgroup
+         \def\noexpand\tabu@temp {\tabucolX@rw{\the\dimexpr\tabu@temp}}%
+         \def\noexpand\tabucolX@rw{%
+            \tabucolX@rw{\tabu@dimexpr{\the\tabu@X@cols}{\tabu@temp}}}%
+         }\x
 }% \tabucolX@do
+\def\tabu@dimexpr#1#2{%
+   \ifdim \tabu@wd{#1}>\p@
+      \ifdim \tabu@wd{#1}<#2 \tabu@wd{#1}\else#2\fi\else #2\fi
+}% \tabu@dimexpr
 \def\tabu@prep@TRIAL{%
    \let\tabu@savedpreamble \@preamble
-   \def\savetabu {\tabu@saveX}%
-   \begingroup\iffalse{\fi\ifnum0=`}\fi
+   \begingroup \iffalse{\fi \ifnum0=`}\fi
       \tabu@setup@TRIAL
-      \iftabu@spread % first trial only
+      \tabucolX \tabu@target
+      \ifcase 0\iftabu@negcoef \else\iftabu@spread \else 1\fi\fi
          \advance\tabu@X@cols \@ne
          \expandafter\let\csname tabu@X\the\tabu@X@cols\endcsname \@undefined
-         \tabu@X@cols \z@ \tabu@naturalX \z@ \tabucolX \z@
-         \let\tabu@naturalX@max \z@
-         \let\tabu@naturalX@min \z@
+         \tabu@X@cols \z@
+         \def\tabu@naturalX@max {\z@}%
+         \def\tabu@naturalX@min {\z@}%
          \let\tabu@startpboxORI \@startpbox
-         \let\@startpbox \tabu@spread@startpbox
-      \else
-         \tabucolX = \tabu@target
+         \let\@startpbox \tabu@measure@startpbox
       \fi
-      \tabu@cnt \z@  % number of trials
-      \def\tabu@lasttry{\m@ne\p@}%
+      \def\tabu@lasttry{\m@ne\p@}\tabu@cnt \z@  % number of trials
       \tabu@arrayleft@measure
 }% \tabu@prep@TRIAL
-\def\tabu@setup@TRIAL{\tabu@global@X
+\def\tabu@setup@TRIAL{\tabu@global@X \let\tabu@global@X \@empty
+   \let\@halignto \@empty  \tabu@naturalX \z@
+   \tabu@savecounters  \let\tabu@savecounters \relax
+   \hbadness \@M    \let\hbadness \@tempcnta
+   \hfuzz \maxdimen \let\hfuzz \@tempdima
    \let\tabu@rewrite@X \tabu@rewrite@Xnested
-   \def\tabudefaulttarget{\linewidth}%
-   \def\@elt##1{\global\value{##1}\the\value{##1}\relax}%
-   \xdef\tabu@global@X {\cl@@ckpt}\let\@elt \relax
-   \hbadness\@M \hfuzz\maxdimen
-   \let\hbadness \@tempcnta
-   \let\hfuzz \@tempdima
-   \let\write \tabu@nowrite
-   \let\@footnotetext\@gobble
-   \long\def\@xfootnote[##1]##2{}%
-   \let\tabu@saveX \@gobble
+   \let\savetabu \@gobble        \let\tabudefaulttarget \linewidth
+   \let\write \tabu@nowrite      \let\GenericError  \tabu@GenericError
+   \long\def\@xfootnote[##1]##2{}\let\@footnotetext \@gobble
+   \ifx\@arrayright\relax \let\@arrayright \@empty\fi
    \tabu@TRIAL@hook
 }% \tabu@setup@TRIAL
-\let\tabu@TRIAL@hook\@empty
-\newcommand\tabuDisableCommands[1]{\g@addto@macro\tabu@TRIAL@hook{#1}}
+\def\tabu@savecounters{%
+   \def\@elt##1{\global\value{##1}\the\value{##1}\relax}%
+   \edef\tabu@global@X {\cl@@ckpt}\let\@elt \relax
+}% \tabu@savecounters
+\let\tabu@TRIAL@hook \@empty
+\newcommand\tabuDisableCommands[1]{\g@addto@macro\tabu@TRIAL@hook {#1}}
 \def\tabu@arrayleft@measure#1\bgroup{%
-  \def\tabu@Xfinish{\ifnum0=`{\fi\iffalse}\fi\endgroup\tabu@global@X #1\bgroup}%
-  \toks@{%
-      \tabu@setup@everycr
-      \let\@preamble\tabu@savedpreamble}% <required for multicolumn>
-  \tabu@collect
+   \def\tabu@Xfinish{%
+      \tabu@global@Xnested \ifnum0=`{}\fi\endgroup
+      \tabu@global@X #1\bgroup}%
+   \def\tabu@TRIAL {\setbox\tabu@box \hbox\bgroup $#1\bgroup
+                                   \the\toks@ \tabu@endTRIAL}%
+   \toks@{\tabu@setup@everycr
+      \let\@preamble \tabu@savedpreamble}% <required for multicolumn>
+   \tabu@collect
 }% \tabu@arrayleft@measure
+\long\def\tabu@long@arrayleft@measure #1\LT@bchunk #2\LT@bchunk{%
+   \def\tabu@Xfinish{%
+      \tabu@global@Xnested \ifnum0=`{}\fi\endgroup
+      \tabu@setup@everycr \let\@preamble \tabu@savedpreamble
+      \tabu@global@X #1\LT@bchunk #2\LT@bchunk}%
+  \def\tabu@TRIAL{%
+      \setbox\tabu@box \hbox\bgroup
+      \tabu@setup@everycr \let\@preamble \tabu@savedpreamble
+      \tabu@global@X \LTchunksize\@M
+      #1\LT@bchunk #2\LT@bchunk \the\toks@ \tabu@endTRIAL}%
+  \toks@{}%\let\LT@output\relax
+  \tabu@collect
+}% \tabu@long@arrayleft@measure
+\def\tabu@long@endTRIAL{%
+   \LT@echunk
+   \global\setbox\@ne \hbox{\unhbox\@ne}\kern\wd\@ne
+   \LT@get@widths
+   \egroup        % got \tabu@box
+   \iftabu@spread \tabu@spreadarith % <only once>
+   \else          \tabu@arith
+   \fi
+   \iftabu@measuring \tabu@measuringfalse
+      \expandafter \tabu@TRIAL % <continue trials>
+   \else
+      \expandafter \tabu@Xfinish
+         \the \expandafter\toks@ \tabu@endenvir  % <we are then!>
+   \fi
+}% \tabu@long@endTRIAL
 \def\tabu@collect{\catcode`\^^@=13\def\tabu@stack{b}\tabu@collectbody}
 \long\def\tabu@collectbody#1\end#2{%
    \edef\tabu@stack{\tabu@pushbegins #1\begin\end\expandafter\@gobble\tabu@stack}%
    \ifx\tabu@stack\@empty
       \toks@\expandafter{\the\toks@#1}\def\tabu@endenvir{\end{#2}}%
-      \expandafter\tabu@TRIAL
+      \expandafter \tabu@TRIAL
    \else
       \toks@\expandafter{\the\toks@#1\end{#2}}%
-      \expandafter\tabu@collectbody
+      \expandafter \tabu@collectbody
    \fi
 }% \tabu@collectbody
 \long\def\tabu@pushbegins#1\begin#2{%
       \ifx\end#2\else b\expandafter\tabu@pushbegins\fi}
-\def\tabu@TRIAL{\setbox\tabu@box \hbox\bgroup $\@arrayleft
-   \if c\tabu@align\vcenter\else\vbox\fi\bgroup \the\toks@
-                                           \tabu@endTRIAL}% constant
 \def\tabu@endTRIAL{%
-   \ifdefined\adl@ncol  % <arydshln in trials>
-      \csname crcr\endcsname
-      \noalign{\global\adl@ncol\tabu@nbcols}\fi
+   \tabu@adl@endTRIAL   % <arydshln in nested trials>
    \endarray$\egroup
-   \iftabu@spread \tabu@spreadfalse
-      \let\@startpbox \tabu@startpboxORI
-      \tabu@spreadarith % <only once>
-   \else \tabu@arith
+   \iftabu@spread \tabu@spreadarith % <only once>
+   \else          \tabu@arith
    \fi
    \iftabu@measuring \tabu@measuringfalse
-         \expandafter \tabu@TRIAL % <continue trials>
+      \expandafter \tabu@TRIAL % <continue trials>
    \else
-         \toks@\expandafter\expandafter\expandafter{%
-               \the\expandafter\toks@ \tabu@endenvir}%
-         \expandafter \tabu@Xfinish \the\toks@ % <we are then!>
+      \expandafter \tabu@Xfinish
+         \the \expandafter\toks@ \tabu@endenvir  % <we are then!>
    \fi
 }% \tabu@endTRIAL
+\def\tabu@adl@endTRIAL{\crcr \noalign{\global\adl@ncol \tabu@nbcols}}
 \def\tabu@arith{%
-   \advance\tabu@cnt \@ne
-%%   \showbox\tabu@box
-   \ifdim \tabu@lasttry=\wd\tabu@box
-      \tabu@message{\tabu@header Reached minimum width. Backing up}%
-   \else
-      \edef\tabu@lasttry{\the\wd\tabu@box}%
-      \tabu@message{\tabu@message@arith}%
-      \ifdim \dimexpr \wd \tabu@box - \tabu@target <\tabu@hfuzz
-         \tabu@message{\tabu@message@reached}%
-         \xdef\tabu@global@X {\tabu@target\the\tabu@target\relax \tabu@global@X
-                              \tabucolX \the\tabucolX\relax}%
-      \else
-         \advance\tabucolX-\dimexpr(\wd\tabu@box-\tabu@target-\tabu@X@sum/65536)
-                              *65536/\tabu@X@sum\relax
+   \advance\tabu@cnt \@ne \tabu@message{\tabu@message@arith}%
+   \ifx \@startpbox\tabu@measure@startpbox
+            \let\@startpbox \tabu@startpboxORI \fi
+   \dimen@ \tabu@X@sum
+   \iftabu@negcoef \tabu@arith@negcoef \fi
+   \ifcase 0\ifdim \dimexpr\wd\tabu@box-\tabu@hfuzz-1sp<\tabu@target
+            \else \ifdim \tabu@lasttry=\wd\tabu@box 1\else
+            2\fi\fi\relax
+      \ifdim \tabu@X@sum=\dimen@ \tabu@message{\tabu@message@reached}%
+      \else\ifdim\tabu@X@sum=\z@ \tabu@message{\tabu@message@reached}%
+      \else\ifnum \tabu@cnt>\@ne \tabu@message{\tabu@message@reached}%
+      \else \tabu@measuringtrue
+            \tabucolX = \dimexpr\tabucolX*\p@/\tabu@X@sum\relax
+      \fi\fi\fi
+   \or \tabu@message{\tabu@header Reached minimum width. Backing up}%
+       \tabu@warn{tabu width = \the\wd\tabu@box\space>
+                  \the\tabu@target\space+ \tabu@hfuzz}%
+   \or
+      \ifdim \tabu@X@sum=\z@ \tabu@measuringtrue \tabucolX=\@tempdima
+      \else \tabu@message{\tabu@message@arith}%
+         \advance\tabucolX-\dimexpr(\wd\tabu@box-\tabu@target-\tabu@X@sum/\p@)
+                                                      *\p@/\tabu@X@sum\relax
          \ifdim \tabucolX<\z@
-            {\let\write\tabu@write\PackageWarning{tabu}
-               {X Columns too narrow (table too wide)\MessageBreak}}%
-               \tabucolX=1em%
+            \tabu@warn{X Columns too narrow (table too wide)}%
+            \tabucolX=\tabucolX@error
          \else \tabu@measuringtrue
+            \ifdim \tabu@X@sum=\dimen@
+               \edef\tabu@lasttry{\the\wd\tabu@box}%
+            \else
+               \ifnum \tabu@cnt>\@ne \edef\tabu@lasttry{\the\wd\tabu@box}\fi
+               \ifdim \tabucolX<\@tempdima \tabucolX \@tempdima\fi
+            \fi
          \fi
       \fi
+   \fi %(ifcase)
+   \iftabu@measuring
+   \else \edef\tabu@global@X{\tabu@global@X
+            \tabucolX    \the\tabucolX\relax
+            \tabu@target \the\tabu@target\relax % < for \savetabu >
+            \ifnum \tabu@nested=\z@
+            \ifx \@arrayright\@empty
+            \ifdim \tabu@X@sum>\z@
+               \def\noexpand\@halignto{to\the\tabu@target}\fi\fi\fi}%
    \fi
+   \tabu@X@sum \dimen@
 }% \tabu@arith
+\def\tabu@arith@negcoef{%
+   \tabu@X@cols \@ne \count@ \tabu@X@cols
+   \@whilesw \ifcsname tabu@X\the\tabu@X@cols\endcsname\fi{%
+      \ifdim \tabu@wd\tabu@X@cols>\p@
+         \expandafter\let\expandafter\tabu@temp
+                   \csname tabu@X\the\tabu@X@cols\endcsname
+         \ifdim \tabu@wd\tabu@X@cols <\tabu@temp\tabucolX
+            \advance\tabu@X@sum -\tabu@temp\p@
+            \tabu@message{\tabu@message@negcoef{\the\tabu@X@cols}}%
+            \ifdim \tabu@wd\tabu@X@cols >\tabu@wd\count@ \count@ \tabu@X@cols \fi
+      \fi\fi
+      \advance\tabu@X@cols \@ne
+   }%
+   \@tempdima=\dimexpr\tabu@wd\count@ * \p@/
+                     \dimexpr\csname tabu@X\the\count@\endcsname\p@\relax\relax
+}% \tabu@arith@negcoef
 \def\tabu@spreadarith{%
    \tabu@naturalX \tabu@naturalX@max\relax
    \tabucolX \tabu@naturalX@min\relax
    \tabu@message{\tabu@message@spread}%
    \ifdim \dimexpr \wd\tabu@box + \tabu@spreadtarget <\tabu@target
-      \advance\tabu@spreadtarget \dimexpr\wd\tabu@box-\tabu@naturalX+\tabucolX\relax
+      \advance\tabu@spreadtarget
+               \dimexpr\wd\tabu@box-\tabu@naturalX+\tabucolX\relax
       \ifdim \tabu@spreadtarget <\tabu@target
-         \tabu@target = \tabu@spreadtarget
+         \tabu@target =\tabu@spreadtarget
       \fi
-      \tabu@message{\expandafter\tabu@msg@align \the\tabu@target {}{}{}{}{}\@@}%
+      \tabu@message{\the\tabu@target}%
       \tabu@message{\ifdim \tabu@spreadtarget>\tabu@target
-                           (tabu) default target used.\fi}%
+                           (tabu) spread reduced to fit default target.\fi}%
    \else
       \tabu@message{\expandafter\tabu@msg@align \the\tabu@target { }{}{}{}{}\@@}
       \tabu@message{(tabu)\ifdim\wd\tabu@box<\tabu@target spread too large\else
                                                  tabu spread is useless here\fi,
                     default target used.}%
    \fi
+   \let\@startpbox \tabu@startpboxORI
    \xdef\tabu@halignto {to\the\tabu@target}%
    \tabucolX \tabu@target
-   \tabu@measuringtrue
+   \tabu@spreadfalse \tabu@measuringtrue
 }% \tabu@spreadarith
 \def\tabu@message@arith{\tabu@header
    \expandafter\tabu@msg@align \the\tabucolX { }{ }{ }{ }{}\@@
    \expandafter\tabu@msg@align \the\wd\tabu@box { }{ }{ }{ }{}\@@
    \expandafter\tabu@msg@align \the\tabu@target { }{ }{ }{ }{}\@@
    \expandafter\tabu@msg@align \the\tabu@X@sum {}{}{}{}{}\@@
+   \ifx\@startpbox\tabu@measure@startpbox\tabu@spaces (coefs<0)\else
+   \ifdim\tabu@X@sum>\z@
    \expandafter\tabu@msg@align \the\dimexpr(\tabu@target-\wd\tabu@box)
-                                      *65536/\tabu@X@sum\relax {}{}{}{}{}\@@}
+                                 *\p@/\tabu@X@sum\relax {}{}{}{}{}\@@\fi\fi}%
 \def\tabu@message@spread{\tabu@spreadheader
    \expandafter\tabu@msg@align \the\tabu@spreadtarget {}{}{}{}{}\@@
    \expandafter\tabu@msg@align \the\wd\tabu@box {}{}{}{}{}\@@
@@ -589,102 +675,112 @@
    \expandafter\tabu@msg@align \expandafter-\the\tabu@naturalX {}{}{}{}{}\@@}
 \def\tabu@message@reached{\tabu@header
    \expandafter\tabu@msg@align \the\tabucolX { }{ }{ }{ }{}\@@
-   ******** Reached Target : hfuzz=\tabu@hfuzz\space ********^^J}
+   \expandafter\tabu@msg@align \the\wd\tabu@box {}{}{}{}{}\@@
+  <\expandafter\tabu@msg@align \the\tabu@target { }{ }{ }{ }{}\@@
+  + \tabu@hfuzz\space= hfuzz *****^^J%
+  (tabu)\tabu@spaces******* Reached Target:
+         hfuzz = \tabu@hfuzz\on@line\space *******^^J
+         \ifnum\tabu@nested=\z@^^J\fi}%
+\def\tabu@message@negcoef #1{\tabu@spaces\tabu@spaces
+   * #1. X[-\csname tabu@X#1\endcsname]: natural width
+   = \tabu@wd{#1}
+   < \csname tabu@X#1\endcsname X
+   = \the\dimexpr\csname tabu@X#1\endcsname\tabucolX
+}% \tabu@message@negcoef
+\edef\tabu@spaces{\@spaces}
 \def\do#1{%
    \def\tabu@msg@align##1.##2##3##4##5##6##7##8##9\@@{%
-   \ifnum##1<10 #1#1#1\else
-   \ifnum##1<100 #1#1\else
+   \ifnum##1<10 #1 #1\else
+   \ifnum##1<100 #1 \else
    \ifnum##1<\@m #1\fi\fi\fi
    ##1.##2##3##4##5##6##7##8#1}%
-   \def\tabu@header{%
-      \ifnum\tabu@cnt=\@ne (tabu)
-       Try#1#1#1#1tabu X#1#1#1#1#1#1tabu Width#1#1#1#1#1Target%
-                  #1#1#1#1#1#1#1#1#1Coefs#1#1#1#1#1#1#1Update^^J\fi
-       (tabu) \ifnum\tabu@cnt<10 #1\fi\the\tabu@cnt)#1#1}%
+   \def\tabu@header{(tabu) \ifnum\tabu@cnt<10 #1\fi\the\tabu@cnt) #1}%
+   \def\tabu@titles{\ifnum \tabu@nested=\z@
+      (tabu) Try#1 #1 tabu X #1 #1 #1tabu Width #1 #1 Target
+                  #1 #1 #1 #1 Coefs #1 #1 #1 Update^^J\fi}%
    \def\tabu@spreadheader{%
-      (tabu) Try#1#1#1#1Spread#1#1#1tabu Width#1#1#1#1#1Min Nat.#1#1#1#1Nat.X%
-                                              #1#1#1#1#1#1#1#1#1New Target^^J%
+      (tabu) Try#1 #1 Spread #1 #1 tabu Width #1 #1 Nat. Min. #1 #1 #1 Nat.X
+                                                      #1 #1 #1 New Target^^J%
       (tabu)spread}%
+   \def\tabu@tracing@save##1{\begingroup
+      \def\col@sep ####1\relax       {(tabu) column sep #1 #1 #1 = ####1^^J}%
+      \def\arrayrulewidth ####1\relax{(tabu) arrayrulewidth #1 = ####1^^J}%
+      \def\doublerulesep ####1\relax {(tabu) doublerulesep #1 #1= ####1^^J}%
+      \def\extrarowheight ####1\relax{(tabu) extrarowheight #1 = ####1^^J}%
+      \def\extratabsurround ####1\relax{(tabu) extratabsurround = ####1^^J}%
+      \def\minrowclearance ####1\relax {(tabu) minrowclearance#1 = ####1^^J}%
+      \def\arraystretch ####1{(tabu) arraystretch #1 #1 = ####1^^J}%
+      \def\NC@find ####1\@nil{(tabu) tabu preamble#1 #1 = \detokenize{####1}^^J}%
+      \def\tabu@wddef####1####2{(tabu) Natural width ####1 = ####2^^J}%
+      \let\edef \@gobbletwo \let\def \@empty
+      \tabu@message{%
+         (tabu) \string\savetabu{##1}: \on@line^^J%
+      \ifx \savetabu\tabusaveX
+         (tabu) X columns width #1 = \the\tabucolX^^J\fi
+         (tabu) target #1 #1 #1 #1 #1 = \the\tabu@target^^J%
+         \tabu@savedparam
+         \tabu@savedpream \@nil
+         \iftabu@negcoef \tabu@savewd\fi}%
+      \endgroup}%
 }\do{ }
-\def\tabu@spread@startpbox#1{\bgroup
-   \in@{\tabucolX}{#1}%
+\def\tabu@measure@startpbox#1{\bgroup
+   \let\@startpbox \tabu@startpboxORI           % in case of nesting
+   \in@{\tabu@dimexpr}{#1}%
    \ifin@
-      \hbox to\tabu@target\bgroup\aftergroup\tabu@spread@endhbox
-         \tabu@spread@startpbox@setup \hfil
-   \else
-      \expandafter\@gobble\tabu@startpboxORI{#1}% \@gobble \bgroup
-   \fi
-}% \tabu@spread@startpbox
-\def\tabu@spread@startpbox@setup{%
-   \let\tabu@vskipORI\vskip \let\tabu@adl@draw\adl@draw
-   \def\adl@draw{\let\vskip\tabu@vskipORI\tabu@adl@draw}%
-   \let\vss\relax\let\vfil\vss\let\vfill\vss\let\vskip\@tempskipa
-}% \tabu@spread@startpbox@setup
-\def\tabu@spread@endhbox{%
-   \ifnum\badness>\@M %<text does not fit>
-      \global\tabu@naturalX \tabu@target
-   \else
-      \setbox\tabu@box\lastbox
-      \setbox\tabu@box\hbox{\unhbox\tabu@box}%
       \global\advance\tabu@X@cols \@ne
-      \ifcsname tabu@X\the\tabu@X@cols\endcsname
-         \global\advance\tabu@naturalX \wd\tabu@box
-      \else
+      \ifcsname tabu@X\the\tabu@X@cols\endcsname\else
          \global\tabu@X@cols \@ne
-         \global\tabu@naturalX \wd\tabu@box
-      \fi
-      \ifdim \tabu@naturalX@max<\tabu@naturalX
-         \xdef\tabu@naturalX@max{\the\tabu@naturalX}%
-      \fi
-      \ifdim \tabu@naturalX@min<\dimexpr \wd\tabu@box * \tabu@X@sum /
-                  (65536*\csname tabu@X\the\tabu@X@cols\endcsname)\relax
-         \xdef\tabu@naturalX@min{\the\dimexpr \wd\tabu@box * \tabu@X@sum /
-                     (65536*\csname tabu@X\the\tabu@X@cols\endcsname)\relax}%
+         \global\tabu@naturalX \z@
       \fi
    \fi
-   \box\tabu@box
-   \egroup % end of \vtop (measure)
-}% \tabu@spread@endhbox
-\newcommand*\tabuvline@rewrite[1][]{\tabuvline@arg{#1}%
-                     \expandafter \NC@find \tabu@temp}
-\def\tabu@vline#1{\vrule width#1}
-
-\def\tabuvline@arg#1{%
-   \ifx\\#1\\%    <shortcut when no option>
-      \edef\tabu@temp{!{%
-         \iftabu@colortbl\begingroup\noexpand\CT@arc@\fi
-         \noexpand\tabu@vline\arrayrulewidth
-         \iftabu@colortbl\endgroup\fi}}%
-   \else \futurelet \tabu@temp \tabuvline@argi #1\p@\p@\@nnil \tabuvline@argiii
-   \fi
-}% \tabuvline@arg
-\def\tabuvline@argi{%
-   \let\tabu@color \@empty
-   \ifcat A\noexpand\tabu@temp
-         \@tempdima\arrayrulewidth
-         \expandafter\tabu@getlinecolor
-   \else \expandafter\tabuvline@argii
+   \iftabu@spread\else
+      \ifin@ {\let\tabu@dimexpr \@firstoftwo\expandafter}%
+             \ifdim \tabu@wd{#1}<\p@ \in@false\fi\fi\fi
+   \ifin@
+      \begingroup \let\tabu@dimexpr \@secondoftwo
+         \edef\x{\endgroup \def\noexpand\tabu@temp{\the\dimexpr#1}%
+      }\x
+      \setbox\tabu@box=\hbox\bgroup
+         \let\tabu@rewrite@X \tabu@@rewrite@X
+         \begin{varwidth}{\tabu@temp}\narrowragged\arraybackslash
+            \tabu@noadjustspacing \parfillskip\@flushglue
+               \bgroup \aftergroup\tabu@measure@endpbox
+   \else
+      \expandafter\@gobble\@startpbox{#1}% \@gobble \bgroup
    \fi
-}% \tabuvline@argi
-\def\tabuvline@argii#1\@nnil{%
-   \tabu@maybecolor \@tempdima #1 \@nnil
-}% \tabuvline@argii
-\def\tabuvline@argiii{%
-   \edef\tabu@temp{!{\begingroup
-      \ifx\tabu@color\@empty
-      \iftabu@colortbl \noexpand\CT@arc@ \fi
-      \else \tabu@color\fi
-      \noexpand\tabu@vline{\the\@tempdima}\endgroup}}%
-}% \tabuvline@argiii
-{
-\expandafter\let\csname NC@find@|\endcsname\relax
-\expandafter\let\csname NC@rewrite@|\endcsname\relax
-\xdef\tabu@lines{%
-   \let\csname NC@find@|\endcsname \noexpand\tabuvlines@find
-   \let\csname NC@rewrite@|\endcsname \noexpand\tabuvline@rewrite
-}% \tabu@vline
-}
-\def\tabuvlines@find#1|{\NC@{#1}}
+}% \tabu@measure@startpbox
+\ifdefined\pdfadjustspacing
+   \def\tabu@noadjustspacing{\pdfadjustspacing\z@}%
+\else
+   \let\tabu@noadjustspacing\relax
+\fi
+\def\tabu@measure@endpbox{%
+   \@finalstrut\@arstrutbox\end{varwidth}\egroup      % <got my \tabu@box>
+   \global\advance\tabu@naturalX \wd\tabu@box
+   \ifdim \tabu@naturalX@max<\tabu@naturalX
+      \xdef\tabu@naturalX@max{\the\tabu@naturalX}\fi
+   \@tempdima=\dimexpr \wd\tabu@box * \tabu@X@sum /
+         \dimexpr\csname tabu@X\the\tabu@X@cols\endcsname\p@\relax\relax
+   \ifdim \tabu@naturalX@min<\@tempdima
+      \xdef\tabu@naturalX@min{\the\@tempdima}\fi
+   \ifdim \tabu@wd\tabu@X@cols>\z@
+   \ifdim \tabu@wd\tabu@X@cols<\wd\tabu@box
+      \tabu@wddef\tabu@X@cols {\the\wd\tabu@box}%
+      \tabu@debug{\tabu@spaces\tabu@spaces
+         * \the\tabu@X@cols. X[-\csname tabu@X\the\tabu@X@cols\endcsname]:
+         target=\the\dimexpr\tabu@temp\relax\space
+         \expandafter\expandafter\expandafter\string\tabu@wd\tabu@X@cols
+         =\tabu@wd\tabu@X@cols}%
+   \fi\fi
+   \box\tabu@box \egroup % end of \vtop (measure)
+}% \tabu@measure@endpbox
+\def\tabu@wd#1{\csname tabu@W\the\tabu@nested @\number#1\endcsname}
+\def\tabu@wddef#1{\expandafter\xdef
+               \csname tabu@W\the\tabu@nested @\number#1\endcsname}
+\def\tabu@wdlet#1{\global\expandafter\let
+               \csname tabu@W\the\tabu@nested @\number#1\endcsname}
+\def\tabu@naturalX@min{\z@}
+\def\tabu@naturalX@max{\z@}
 \def\tabu@setup@everycr{%
    \tabu@firstclinetrue
    \let\tabu@first@cline \z@
@@ -708,7 +804,7 @@
       \global\minrowclearance \z@
    \fi
    \global\let\vcenter \vbox
-   \iftabu@nested\vspace*{\dimexpr\extrarowheight-\ht\@arstrutbox}\fi
+   \ifnum \tabu@nested>\z@ \vspace*{\dimexpr\extrarowheight-\ht\@arstrutbox}\fi
    \toks@{}\count@\@ne
    \@whilenum\count@<\tabu@nbcols\do{\advance\count@\@ne
                         \toks@\expandafter{\the\toks@&}}%
@@ -721,17 +817,55 @@
          \global\let\tabu@first@cline \@ne}}%
    \expandafter}\the\toks@
 }% \tabuphantomline
+\def\tabu@lines{{\endlinechar\m@ne \scantokens{\def\x{|}}%
+   \expandafter}\expandafter\tabu@lines@ \x
+}% \tabu@lines
+\def\tabu@lines@#1{%
+   \tabu@newcolumntype #1{\tabuvline@rewrite}%
+   \NC@list\expandafter{\the\NC@list \NC@do #1}%
+}% \tabu@lines@
+\newcommand*\tabuvline@rewrite[1][]{\tabuvline@arg{#1}%
+                     \expandafter \NC@find \tabu@temp}
+\def\tabu@vline#1{\vrule width#1}
+
+\def\tabuvline@arg#1{%
+   \ifx\\#1\\%    <shortcut when no option>
+      \edef\tabu@temp{!{%
+         \iftabu@colortbl\begingroup\noexpand\CT@arc@\fi
+         \noexpand\tabu@vline\arrayrulewidth
+         \iftabu@colortbl\endgroup\fi}}%
+   \else \futurelet \tabu@temp \tabuvline@argi #1\p@\p@\@nnil \tabuvline@argiii
+   \fi
+}% \tabuvline@arg
+\def\tabuvline@argi{%
+   \let\tabu@color \@empty
+   \ifcat A\noexpand\tabu@temp
+         \@tempdima\arrayrulewidth
+         \expandafter\tabu@getlinecolor
+   \else \expandafter\tabuvline@argii
+   \fi
+}% \tabuvline@argi
+\def\tabuvline@argii#1\@nnil{%
+   \tabu@maybecolor \@tempdima #1 \@nnil
+}% \tabuvline@argii
+\def\tabuvline@argiii{%
+   \edef\tabu@temp{!{\begingroup
+      \ifx\tabu@color\@empty
+      \iftabu@colortbl \noexpand\CT@arc@ \fi
+      \else \tabu@color\fi
+      \noexpand\tabu@vline{\the\@tempdima}\endgroup}}%
+}% \tabuvline@argiii
 \def\tabu@linedash{4pt}%   <default value>
 \def\tabu@dashgap{4pt}%    <default value>
-\def\tabucline{\noalign{\ifnum0=`}\fi\@ifstar
+\def\tabucline{\noalign{\ifnum0=`}\fi \@ifstar
    {\@tempswatrue\tabu@cline}
    {\@tempswafalse\tabu@cline}}%
-\newcommand*\tabu@cline[2][]{%
+\newcommand*\tabu@cline[2][]{\toks@{}%
    \tabu@startstop{#2}\tabu@getlinespec{#1}\@multicnt\@ne
-   \ifnum\tabu@start>\tabu@stop \the\toks@
-   \else\ifx\tabu@xleaders\relax\the\toks@
+   \ifnum\tabu@start>\tabu@stop
+   \else\ifx\tabu@xleaders\relax
    \else
-      \toks@{\ifnum0=`{\fi}\noalign{\global\let\@arstrutbox \voidb@x}}%
+      \toks@{\noalign{\global\let\@arstrutbox \voidb@x}}%
 %%      \iftabu@firstcline\if\tabu@align t\vskip-\ht\@arstrutbox\fi\fi
       \@whilenum\@multicnt<\tabu@start\do{\advance\@multicnt\@ne
                               \toks@\expandafter{\the\toks@ &}}%
@@ -741,11 +875,11 @@
          \expandafter \tabu@add \csname tabu@tok@\the\@multicnt L\endcsname \@nil
          \fi
          \ifcase 0\if@tempswa\else\ifnum \@multicnt<\tabu@stop 1\fi\fi\relax
-            \toks@\expandafter{\the\toks@ \color@begingroup}%
-            \toks@\expandafter\expandafter\expandafter{\expandafter\the
-                              \expandafter\toks@ \tabu@xleaders \color@endgroup}%
+            \toks@\expandafter{\the\toks@ \begingroup}%
+            \toks@\expandafter{\the\expandafter\toks@
+                               \tabu@xleaders \endgroup}%
          \fi
-         \ifcase 0\if@tempswa\else\ifnum \@multicnt<\tabu@stop 1\fi\fi %
+         \ifcase 0\if@tempswa\else\ifnum \@multicnt<\tabu@stop 1\fi\fi\relax
          \expandafter \tabu@add \csname tabu@tok@\the\@multicnt R\endcsname \@nil
          \fi
          \ifnum\@multicnt<\tabu@stop
@@ -755,13 +889,14 @@
       \repeat
       \@whilenum\@multicnt<\tabu@nbcols\do{\advance\@multicnt\@ne
                               \toks@\expandafter{\the\toks@ &}}%
-      \toks@\expandafter{\the\toks@ \cr \noalign{%
-                     \global\let\@arstrutbox \tabu@arstrutbox}}%
-%%      \message{LIGNE AJOUTEE:\the\toks@}%
-      \the\toks@
+      \toks@\expandafter{\the\toks@ \cr
+            \noalign{\global\let\@arstrutbox \tabu@arstrutbox}}%
+%%      \tabu@debug{LIGNE AJOUTEE:\the\toks@}%
    \fi\fi
-}% \tabucline
-\def\tabu@add #1\@nil{\toks@\expandafter{\the\toks@ #1\ifmmode$\fi}}
+   \ifnum0=`{\fi\expandafter}\the\toks@
+}% \tabu@cline
+\def\tabu@add #1\@nil{\toks@\expandafter{\the\toks@
+              \begingroup #1\endgroup\ifmmode$\fi}}
 \def\tabu@startstop#1{\tabu@start@stop #1\relax 1-\tabu@nbcols\@nnil}
 \def\tabu@start@stop #1-#2\@nnil{%
    \@defaultunits \tabu@start \number0#1\relax\@nnil
@@ -782,7 +917,8 @@
    \else \tabu@getline{#1\p@ on0pt off0pt}\fi\fi\fi\fi\fi
 }% \tabu@getlinespec
 \def\tabu@defleaders#1{%
-   \def\tabu@xleaders{\xleaders\hbox{\lower.5\extrarowheight#1}\tabu@leaderfill}}
+   \def\tabu@xleaders{\iftabu@colortbl\CT@arc@\fi
+      \xleaders\hbox{\lower.5\extrarowheight#1}\tabu@leaderfill}}
 \def\tabucline@warn#1{\PackageWarning{tabu}
    {Undefined line syle: #1
    \MessageBreak Using default line style instead}%
@@ -803,13 +939,16 @@
       \tabu@lineoff #1 on#2 off\tabu@dashgap \p@ \@nnil
    \else
       \tabu@maybecolor \@tempdima \arrayrulewidth #1\p@\@nnil
-      \ifx\tabu@color\@empty \tabucline@warn{#4}\else
+      \ifx\tabu@color\@empty \tabucline@warn\@tempa\else
       \@tempdimb \z@
       \tabu@lineoff off0pt \p@\@nnil \fi
    \fi
 }% \tabu@lineon
 \def\tabu@lineoff #1off#2\@nnil{%
    \tabu@maybecolor \@tempdimc #2\p@ \@nnil
+   \iftabu@colortbl \ifx \tabu@color\@empty
+      \def\tabu@color{\noexpand\CT@arc@}%
+   \fi\fi
    \ifdim \@tempdimb=\z@
       \ifdim \@tempdimc>\z@ \@tempdimb \tabu@dashgap\relax\fi\fi
    \ifdim \@tempdimc=\z@
@@ -862,8 +1001,9 @@
    \endgroup
 }% \tabu@linestyle
 \expandafter\def \csname tabu@line@style@\endcsname {%
-                                     \let\tabu@xleaders \tabu@defaultleaders}%
-\def\tabu@defaultleaders{\leaders
+                                    \let\tabu@xleaders \tabu@defaultleaders}%
+\def\tabu@defaultleaders{\iftabu@colortbl\CT@arc@\fi
+   \leaders
    \iftabu@firstcline
       \vrule  depth \arrayrulewidth
    \else
@@ -873,9 +1013,11 @@
    \tabu@leaderfill}
 \let\tabu@leaderfill \hfil
 {\catcode32=13\relax\catcode`\^^@=13\relax
-\gdef\tabu@verb{\@sanitize\makeatletter\catcode`\^=7\edef\^{\string^}%
-\catcode32=13\let =\ \catcode`\^^@=13\def^^@{\linebreak}\endlinechar\m@ne}%
-}
+\gdef\tabu@verb{\@sanitize\catcode`\^=7\edef\^{\string^}\tabu@makeatletter
+\catcode32=13\let =\ \catcode`\^^@=13\def^^@{\hskip\parfillskip\null\linebreak}%
+\endlinechar\m@ne}}
+{\catcode64=13\edef @{\string @}\expandafter\xdef
+   \csname tabu@makeatletter\endcsname{\catcode64=13\def\noexpand @{\unskip @}}}
 \newcommand\tabu@sanitizetext[1][\ttfamily]{\begingroup
                         \tabu@verb #1\tabu@s@nitizetext}
 \long\def\tabu@s@nitizetext#1{\@makeother\{\@makeother\}%
@@ -884,7 +1026,7 @@
    \def\tabu@decimal{#1}\@temptokena{}%
    \let\tabu@getdecimal@ \tabu@getdecimal@ignorespaces
    \tabu@scandecimal
-}% \tabudecimal
+}% \tabu@tabudecimal
 \def\tabu@scandecimal{\futurelet \tabu@temp \tabu@getdecimal@}
 \def\tabu@skipdecimal#1{#1\tabu@scandecimal}
 \def\tabu@getdecimal@ignorespaces{%
@@ -903,6 +1045,7 @@
    \def\tabu@get@decimalspace#1{%
       \@temptokena\expandafter{\the\@temptokena #1}\tabu@scandecimal}%
 }\do{ }
+\let\tabu@@tabudecimal \tabu@tabudecimal
 \def\tabu@getdecimal{%
    \ifcase    0\ifx 0\tabu@temp\else
                \ifx 1\tabu@temp\else
@@ -939,23 +1082,73 @@
 }% \tabu@printdecimal
 \newcommand*\savetabu[1]{\noalign{%
    \ifx\\#1\\\tabu@savewarn{}{The tabu will not be saved}\else
-      \@ifundefined{tabu@save@\string#1}{}{\tabu@savewarn{#1}{Overwritting}}%
-      {\toks@\expandafter{\tabu@saved}%
-      \expandafter\xdef\csname tabu@saved@\string#1\endcsname{%
-         \tabu@target\the\tabu@target\relax
-         \the\toks@}}%
-   \fi}%
-}% \savetabu
-\def\tabu@saveX#1{\noalign{%
-   \ifx\\#1\\\tabu@savewarn{}{The tabu will not be saved}\else
       \@ifundefined{tabu@saved@\string#1}{}{\tabu@savewarn{#1}{Overwritting}}%
-      {\toks@\expandafter{\tabu@saved}%
-      \expandafter\xdef\csname tabu@saved@\string#1\endcsname{%
-         \tabucolX\the\tabucolX\relax
-         \tabu@target\the\tabu@target\relax
-         \the\toks@}}%
+      {%
+      \toks0\expandafter{\@preamble}%
+      \toks1\expandafter{\tabu@savedparam}%
+      \toks2\expandafter{\tabu@savedpream}%
+      \iftabu@colortbl
+         \toks3\expandafter{\expandafter\gdef\expandafter\CT@arc@
+            \expandafter{\CT@arc@}}%
+         \toks3\expandafter{\the\toks\expandafter3
+            \expandafter\gdef\expandafter\CT@drsc@\expandafter{\CT@drsc@}}%
+      \else \toks3{}%
+      \fi
+      \iftabu@negcoef
+         \edef\tabu@savewd{\tabu@savewd{\number\numexpr1}}%
+         \toks3\expandafter{\the\toks\expandafter3\tabu@savewd}\fi
+      \expandafter\xdef\csname tabu@saved@\string#1\endcsname##1{%
+         \noexpand\ifcase##1\relax
+            \noexpand\ifdim\tabu@target>\z@
+               \noexpand\tabu@warn@usetabu
+            \noexpand\fi
+            \tabu@target \the\tabu@target\relax
+            \tabucolX \the\tabucolX\relax
+            \the\toks1%
+            \gdef\noexpand\tabu@usetabu{%
+               \the\toks1%
+               \def\noexpand\@halignto{\@halignto}%
+               \tabucolX \the\tabucolX\relax
+               \def\noexpand\@preamble{\the\toks0}%
+               \noexpand\tabu@make@arstrutbox
+               \the\toks3
+               \noexpand\ifx \noexpand\tabu@align\noexpand\tabu@aligndefault@text
+                  \def\noexpand\tabu@align{\tabu@align}%
+               \noexpand\fi}%
+            \aftergroup\noexpand\tabu@usetabu
+         \noexpand\else
+            \noexpand\ifdim\tabu@target=\z@
+               \tabu@target \the\tabu@target\relax
+            \noexpand\fi
+            \gdef\noexpand\tabu@preamble{%
+               \noexpand\ifx \noexpand\tabu@align\noexpand\tabu@aligndefault@text
+                  \def\noexpand\tabu@align{\tabu@align}%
+               \noexpand\fi}%
+            \aftergroup\noexpand\tabu@preamble
+         \noexpand\fi
+         \the\toks2}%
+      \tabu@message@save{#1}}%
    \fi}%
-}% \tabu@saveX
+}% \savetabu
+\def\tabu@aligndefault@text{\tabu@aligndefault}%
+\def\tabu@warn@usetabu{\PackageWarning{tabu}
+   {Specifying a target with \string\usetabu\space is useless
+   \MessageBreak The target cannot be changed!}}
+\def\tabu@savewd#1{%
+   \ifnum#1>\tabu@nbcols \expandafter \@gobble
+   \else \ifdim\tabu@wd{#1}>\z@
+         \noexpand\tabu@wddef{#1}{\tabu@wd{#1}}\fi
+         \expandafter\tabu@savewd % loop
+   \fi{#1+1}%
+}% \tabu@savewd
+\def\tabu@make@arstrutbox{%
+  \@tempdima \ht \strutbox
+  \advance \@tempdima by\extrarowheight
+  \setbox \@arstrutbox \hbox{\vrule
+             \@height \arraystretch \@tempdima
+             \@depth \arraystretch \dp \strutbox
+             \@width \z@}%
+}% \tabu@make@arstrutbox
 \def\tabu@savewarn#1#2{\PackageInfo{tabu}
    {User-name `#1' already used for \string\savetabu
    \MessageBreak #2}}%
@@ -965,15 +1158,17 @@
 \def\tabu@rowfont{\noalign{\ifnum0=`}\fi\tabu@row@font}
 \newcommand*\tabu@row@font[2][]{%
    \global\let\tabu@rowfontreset \tabu@rowfont@reset
-   \global\let\tabu@@cellleft \tabu@cellleft
-   \global\let\tabu@@cellright \tabu@cellright
-   \gdef\tabu@cellfont{#2}%
+   \global\let\tabu@@cellleft    \tabu@cellleft
+   \global\let\tabu@@cellright   \tabu@cellright
+   \gdef\tabu@cellfont{\let\color \tabu@colorleavevmode#2\let\color \tabu@colorORI}%
    \ifcsname tabu@cell@#1\endcsname  % row alignment
          \csname tabu@cell@#1\endcsname \fi
    \toks@\expandafter {\tabu@cellleft\tabu@cellfont}% inside \noalign group ok
    \xdef\tabu@cellleft {\the\toks@}%
    \ifnum0=`{\fi}% end of noalign group
 }% \rowfont
+\def\tabu@colorleavevmode{\leavevmode\tabu@colorORI}
+\AtBeginDocument{\let\tabu@colorORI \color}
 \def\tabu@rowfont@reset{%
    \noalign{%
       \global\let\tabu@rowfontreset \@empty
@@ -986,7 +1181,7 @@
 }% \tabu@rowfont@reset
 \let\tabu@rowfontreset\@empty
 \newif\iftabu@cellright
-\AtBeginDocument{\let\array@prepnext@tok \prepnext@tok }% original definition
+\AtBeginDocument{\let\tabu@prepnext@tokORI \prepnext@tok }% original definition
 \def\tabu@prepnext@tok{%
    \ifnum \count@<\z@  % <first initialisation>
       \@tempcnta \@M   % <not initialized by array.sty>
@@ -1004,9 +1199,7 @@
             \tabu@cellrightfalse % <only once>
             \tabu@savetok R\tabu@preptokenright
          \fi
-         \ifnum \tabu@nbcols=\@ne
-            \tabu@savetok L% LEFT token is always empty unless >{...}
-         \fi
+         \ifnum \tabu@nbcols=\@ne \tabu@savetok L\fi
          \tabu@preptokenleft
       \or                     % (case 1) previous token is right
          \tabu@savetok R\tabu@cellrighttrue
@@ -1022,7 +1215,7 @@
          \fi
       \fi % \ifcase
    \fi
-   \array@prepnext@tok
+   \tabu@prepnext@tokORI
 }% \tabu@prepnext@tok
 \def\tabu@preptokenright{%
    \advance \count@ \m@ne
@@ -1036,16 +1229,17 @@
    \expandafter\tabu@savet@k\csname tabu@tok@\the\tabu@nbcols #1\endcsname
 }% \tabu@savetok
 \def\tabu@savet@k#1{%
-   \@temptokena\toks\count@
-   \ifx#1\relax\else \@temptokena\expandafter\expandafter
-                     \expandafter{\expandafter#1\the\@temptokena}%
-   \fi
-   \@temptokena\expandafter{\expandafter\def\expandafter#1\expandafter{%
-                                                      \the\@temptokena}}%
-   \toks@\expandafter\expandafter\expandafter{\expandafter\tabu@global@temp
-                                                      \the\@temptokena}%
-   \xdef\tabu@global@temp{\the\toks@}%
-   \expandafter\endgroup \the\@temptokena
+   \ifnum \@chclass=\@ne \toks@\toks\count@
+   \else\ifnum\@chclass=5 \toks@\toks\count@
+   \else \toks@{}\fi\fi
+   \unless\ifx#1\relax
+      \toks@\expandafter\expandafter\expandafter{%
+                        \expandafter#1\the\toks@}\fi
+   \toks@\expandafter{\expandafter\def\expandafter#1\expandafter{%
+                                                      \the\toks@}}%
+   \@temptokena\expandafter{\tabu@global@temp}%
+   \xdef\tabu@global@temp {\the\@temptokena \the\toks@}%
+   \expandafter\endgroup \the\toks@
 }% \tabu@savetok
 \let\tabu@cellleft\@empty
 \let\tabu@cellright\@empty
@@ -1239,9 +1433,15 @@
 }% \tabu@adl@xarraydashrule
 \def\tabu@adl@act@endpbox{%
    \unskip \ifhmode \nobreak \fi    \@finalstrut \@arstrutbox
-   \egroup
+   \egroup \egroup
    \adl@colhtdp \box\adl@box \hfil
 }% \tabu@adl@act@endpbox
+\def\tabu@adl@fix{%
+   \let\adl@xarraydashrule \tabu@adl@xarraydashrule % <fix> arydshln
+   \let\adl@act@endpbox    \tabu@adl@act@endpbox    % <fix> arydshln
+   \let\adl@act@@endpbox   \tabu@adl@act@endpbox    % <fix> arydshln
+   \let\@preamerror        \@preamerr               % <fix> arydshln
+}% \tabu@adl@fix
 \endinput
 %%
 %% End of file `tabu.sty'.