[pstricks] bug pstricks x positions of nodes set before and after fnode, not center of fnode

[Herbert Voss]

jean-pierre moreau schrieb:
> See below latex source for this intricate bug. I think it is a bug, but I am
> somewhat confused, I find it difficult to explain. I include below latex file
> to explain it, by trying to confine this (supposed) bug of pstricks node.
> 
> The pdf output is same as the ps output (as seen by gv, of
> ghostscript, which I think
> does the ps2pdf too). It is from:
>     $ latex bug-pstricks-node-positions.tex
>     $ dvips -o bug-pstricks-node-positions.ps bug-pstricks-node-positions.dvi
>     $ ps2pdf bug-pstricks-node-positions.ps bug-pstricks-node-positions.pdf
> on my GNU/Linux Slackware-12.1 system, with an old pstricks and a much
> recent one

yes, that looks like a bug. But I have no idea why the maxro
uses a \hbox, which causes the problem. Here is an example
which should work in the expected way:

\documentclass[12pt]{article}
\usepackage{pst-node}

\makeatletter
\def\fnode at ii(#1)#2{%
  \begin at ClosedObj%
  \ifnodealign%
    \kern\psk at framewidth\p@%
    \vrule width\z@ height \psk at frameheight\p@ depth \psk at frameheight\p@%
    \def\pst at coor{0 0 }%
  \else\pst@@getcoor{#1}\fi
  \pst at newnode{#2}{14}{}{
    \pst at coor
    /Y ED /X ED
    /d \psk at dimen .5 sub CLW mul neg def
    /r \psk at framewidth d add def
    /l r neg def
    /u \psk at frameheight d add def
    /d u neg def
    /NodePos { \tx at GetRnodePos } def}%
  \addto at pscode{
    /x2 \psk at framewidth CLW \psk at dimen mul sub def
    /y2 \psk at frameheight CLW \psk at dimen mul sub def
    \pst at coor 2 copy
    y2 sub /y1 ED  x2 sub /x1 ED
    y2 add /y2 ED  x2 add /x2 ED
    \psk at cornersize
    1 index 0 eq { pop pop \tx at Rect } { \tx at OvalFrame } ifelse}%
  \def\pst at linetype{2}%
  \end at ClosedObj%
  \ifnodealign\pst at dimb=\psk at framewidth\p@%
    \kern0.5\pst at dimb\fi
  \ignorespaces}
\makeatother

\begin{document}
foo

     z  \quad
        \pnode{testL1}
        \fnode[linecolor=lightgray,framesize=6pt 50pt](0,.5ex){eqL}
        \pnode(0,2ex){testL2}
        \quad
     =
        \quad%
        \pnode{testR1}
        \fnode[linecolor=lightgray,framesize=6pt 50pt](0,.5ex){eqR}
        \pnode(0,2ex){testR2}
        \quad
     z
  \ncline[linecolor=red]{testL1}{testR1}
  \ncline[linecolor=blue]{testL2}{testR2}

bar

\bigskip now with an aligned node
\psset{nodealign=true}

foo

     z  \quad
        \pnode{testL1}
        \fnode[linecolor=lightgray,framesize=6pt 50pt](0,.5ex){eqL}
        \pnode(0,2ex){testL2}
        \quad
     =
        \quad%
        \pnode{testR1}
        \fnode[linecolor=lightgray,framesize=6pt 50pt](0,.5ex){eqR}
        \pnode(0,2ex){testR2}
        \quad
     z
  \ncline[linecolor=red]{testL1}{testR1}
  \ncline[linecolor=blue]{testL2}{testR2}

bar
\end{document}


Herbert