[texhax] \vline and fat column rules

[Fabian Scheler]

Hi,

while creating an appropriate example I found out, that the behaviour
described above only occurs, when I pass the width of  the rule
created by my version of \vline as parameter, but not if this width is
fixed. The example pasted below should demonstrate this.  The first
table uses a specialized \vline command with hard coded rule width and
the second table one with a vairable rule width. Can anybody explain
this?

Thanks in advance.

Ciao, Fabian

\documentclass{article}
\usepackage{array}
\usepackage{multirow}

\newlength{\savedwidth}
\newcolumntype{I}{!{\vrule width 1pt}}
\newcommand\wvlinevar[1]{{\global\savedwidth\arrayrulewidth%
\global\arrayrulewidth #1}%
\vline
{\global\arrayrulewidth\savedwidth}}
\newcommand\wvlineconst{{\global\savedwidth\arrayrulewidth%
\global\arrayrulewidth 1pt}%
\vline
{\global\arrayrulewidth\savedwidth}}

\begin{document}

\begin{table*}[htbp]
\begin{tabular}{Il|*{5}{l|}lI}
  \hline
  \multirow{2}*{column A} & \multicolumn{2}{c}{Multicolumn}
\wvlineconst & & & \multicolumn{2}{c}{Multicolumn} \wvlineconst \\
\cline{2-7}
  & column B & column C & column D & column E & column F & column G \\ \hline
\end{tabular}
\end{table*}

\vspace{2cm}

\begin{table*}[htbp]
\begin{tabular}{Il|*{5}{l|}lI}
  \hline
  \multirow{2}*{column A} & \multicolumn{2}{c}{Multicolumn}
\wvlinevar{1pt}  & & & \multicolumn{2}{c}{Multicolumn} \wvlinevar{1pt}
\\ \cline{2-7}
  & column B & column C & column D & column E & column F & column G \\ \hline
\end{tabular}
\end{table*}
\end{document}