[pstricks] Trouble with \pssin inside clipping path

[Uwe Siart]

On 9 May 2015 at 16:43, Herbert Voss wrote:

> try it with the attached pst-coil.pro The problem is that the Sin
> function uses the translate operator. All following coordinates refer
> to this new origin. 

Thanks, Herbert, for making effort on a solution. The new prologue file 
seems to allow for using \pssin just once. If it appears a second time 
it bombs again:

\documentclass{article}
\usepackage{pstricks}
\usepackage{pst-coil}
\begin{document}
\begin{pspicture}[showgrid=true](0,0)(9,7)
  \pscustom{%
    \psline(0,4)(2,6)%
    \pssin(2,6)(6,6)%
    \psline(6,6)(8,4)%
    \pssin(8,4)(8,0)%
    \psline(8,0)(0,0)%
  }
\end{pspicture}
\end{document}

-- 
Uwe